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  Subjects -> BIOLOGY (Total: 2998 journals)
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MICROBIOLOGY (255 journals)                  1 2 | Last

Showing 1 - 200 of 255 Journals sorted alphabetically
Acta Microbiologica et Immunologica Hungarica     Full-text available via subscription   (Followers: 4)
Acta Neurobiologiae Experimentalis     Open Access  
Addiction Genetics     Open Access   (Followers: 7)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 22)
Advances in Microbiology     Open Access   (Followers: 23)
Advances in Molecular Imaging     Open Access   (Followers: 1)
African Journal of Clinical and Experimental Microbiology     Open Access   (Followers: 1)
African Journal of Microbiology Research     Open Access   (Followers: 2)
Algorithms for Molecular Biology     Open Access   (Followers: 4)
American Journal of Infectious Diseases and Microbiology     Open Access   (Followers: 23)
American Journal of Microbiological Research     Open Access   (Followers: 2)
American Journal of Microbiology     Open Access   (Followers: 18)
American Journal of Molecular Biology     Open Access   (Followers: 3)
American Journal of Stem Cell Research     Open Access   (Followers: 4)
Annals of Clinical Microbiology and Antimicrobials     Open Access   (Followers: 8)
Annals of Microbiology     Hybrid Journal   (Followers: 10)
Annual Review of Microbiology     Full-text available via subscription   (Followers: 41)
Antimicrobial Agents and Chemotherapy     Hybrid Journal   (Followers: 25)
Antiviral Research     Hybrid Journal   (Followers: 7)
Applied and Environmental Microbiology     Hybrid Journal   (Followers: 46)
Applied Biochemistry and Microbiology     Hybrid Journal   (Followers: 17)
Applied Microbiology and Biotechnology     Hybrid Journal   (Followers: 62)
Aquatic Microbial Ecology     Hybrid Journal   (Followers: 5)
Archives of Microbiology     Hybrid Journal   (Followers: 8)
Avicenna Journal of Clinical Microbiology and Infection     Open Access   (Followers: 2)
Bangladesh Journal of Medical Microbiology     Open Access   (Followers: 3)
Beneficial Microbes     Full-text available via subscription   (Followers: 2)
Bio-Research     Full-text available via subscription   (Followers: 2)
BioArchitecture     Full-text available via subscription  
Bioethanol     Open Access  
Biomaterials Science     Full-text available via subscription   (Followers: 10)
BioMolecular Concepts     Hybrid Journal   (Followers: 2)
Biomolecular Detection and Quantification     Open Access  
Biomolecules     Open Access   (Followers: 2)
Biotechnology and Molecular Biology Reviews     Open Access   (Followers: 1)
BMC Microbiology     Open Access   (Followers: 11)
Brazilian Journal of Microbiology     Open Access   (Followers: 3)
Canadian Journal of Infectious Diseases and Medical Microbiology     Open Access   (Followers: 4)
Canadian Journal of Microbiology     Hybrid Journal   (Followers: 5)
Cell Biology : Research & Therapy     Hybrid Journal   (Followers: 5)
Cell Host & Microbe     Full-text available via subscription   (Followers: 19)
Cell Medicine     Open Access   (Followers: 4)
Cell Regeneration     Open Access   (Followers: 1)
Cell Stem Cell     Full-text available via subscription   (Followers: 34)
CellBio     Open Access  
Cells     Open Access   (Followers: 2)
Cellular & Molecular Immunology     Hybrid Journal   (Followers: 13)
Cellular and Molecular Biology Letters     Open Access   (Followers: 1)
Cellular and Molecular Life Sciences (CMLS)     Hybrid Journal   (Followers: 5)
Cellular Microbiology     Hybrid Journal   (Followers: 9)
Cheese: Chemistry, Physics and Microbiology     Full-text available via subscription   (Followers: 2)
Chimerism     Full-text available via subscription  
Clinical Microbiology and Infection     Hybrid Journal   (Followers: 22)
Clinical Microbiology Newsletter     Hybrid Journal   (Followers: 8)
Clinical Microbiology Reviews     Hybrid Journal   (Followers: 17)
Comparative Immunology, Microbiology and Infectious Diseases     Hybrid Journal   (Followers: 11)
Computational Molecular Bioscience     Open Access   (Followers: 2)
Critical Reviews in Microbiology     Hybrid Journal   (Followers: 14)
Current Clinical Microbiology Reports     Hybrid Journal   (Followers: 2)
Current Issues in Molecular Biology     Open Access   (Followers: 3)
Current Microbiology     Hybrid Journal   (Followers: 14)
Current Molecular Biology Reports     Hybrid Journal   (Followers: 1)
Current Molecular Imaging     Hybrid Journal  
Current Opinion in Microbiology     Hybrid Journal   (Followers: 33)
Current Tissue Engineering     Hybrid Journal   (Followers: 2)
Current Topics in Microbiology and Immunology     Hybrid Journal   (Followers: 12)
Diagnostic Microbiology and Infectious Disease     Hybrid Journal   (Followers: 9)
DNA Barcodes     Open Access  
Egyptian Journal of Biochemistry and Molecular Biology     Full-text available via subscription  
Emerging Microbes & Infections     Open Access   (Followers: 3)
Environmental Microbiology     Hybrid Journal   (Followers: 20)
Environmental Microbiology Reports     Hybrid Journal   (Followers: 6)
Enzyme and Microbial Technology     Hybrid Journal   (Followers: 13)
Epigenetics of Degenerative Diseases     Open Access   (Followers: 5)
European Journal of Clinical Microbiology & Infectious Diseases     Hybrid Journal   (Followers: 18)
European Journal of Microbiology and Immunology     Open Access   (Followers: 8)
Experimental and Molecular Pathology     Hybrid Journal   (Followers: 4)
Experimental Cell Research     Hybrid Journal   (Followers: 5)
Fems Microbiology Ecology     Hybrid Journal   (Followers: 9)
Fems Microbiology Letters     Hybrid Journal   (Followers: 21)
Fems Microbiology Reviews     Hybrid Journal   (Followers: 26)
Fermentation     Open Access   (Followers: 1)
Folia Histochemica et Cytobiologica     Open Access  
Folia Microbiologica     Hybrid Journal   (Followers: 1)
Food Microbiology     Hybrid Journal   (Followers: 17)
Frontiers in Cell and Developmental Biology     Open Access   (Followers: 5)
Frontiers in Cellular and Infection Microbiology     Open Access   (Followers: 3)
Frontiers in Cellular Neuroscience     Open Access   (Followers: 8)
Frontiers in Microbiology     Open Access   (Followers: 14)
Frontiers in Molecular Neuroscience     Open Access   (Followers: 5)
Future Microbiology     Hybrid Journal   (Followers: 5)
Future Virology     Hybrid Journal   (Followers: 8)
Gene Expression     Full-text available via subscription  
Genetics and Molecular Research     Open Access   (Followers: 4)
Geomicrobiology Journal     Hybrid Journal   (Followers: 3)
Gut Microbes     Full-text available via subscription   (Followers: 8)
IAWA Journal     Hybrid Journal   (Followers: 1)
Indian Journal of Microbiology     Hybrid Journal   (Followers: 2)
Indian Journal of Pathology and Microbiology     Open Access   (Followers: 1)
Infection Ecology & Epidemiology     Open Access   (Followers: 6)
Inside the Cell     Open Access  
International Journal of Antimicrobial Agents     Hybrid Journal   (Followers: 9)
International Journal of Bioassays     Open Access   (Followers: 2)
International Journal of Biotechnology and Molecular Biology Research     Open Access   (Followers: 2)
International Journal of Food Microbiology     Hybrid Journal   (Followers: 13)
International Journal of Genetics and Molecular Biology     Open Access  
International Journal of Infection and Microbiology     Open Access   (Followers: 1)
International Journal of Medical Microbiology     Hybrid Journal   (Followers: 8)
International Journal of Molecular Medicine     Full-text available via subscription   (Followers: 5)
International Journal of Mycobacteriology     Open Access  
International Journal of Systematic and Evolutionary Microbiology     Full-text available via subscription   (Followers: 4)
International Journal of Virology and Molecular Biology     Open Access  
International Microbiology     Open Access   (Followers: 4)
Invertebrate Immunity     Open Access   (Followers: 1)
JMM Case Reports     Open Access  
Journal of Cell Science & Therapy     Open Access   (Followers: 2)
Journal of Microbial & Biochemical Technology     Open Access   (Followers: 2)
Journal of Applied Biology & Biotechnology     Open Access   (Followers: 2)
Journal of Applied Microbiology     Hybrid Journal   (Followers: 15)
Journal of Bacteriology     Hybrid Journal   (Followers: 29)
Journal of Basic Microbiology     Hybrid Journal   (Followers: 3)
Journal of Biochemistry and Molecular Biology Research     Open Access  
Journal of Biomolecular Structure and Dynamics     Hybrid Journal   (Followers: 2)
Journal of Bionanoscience     Full-text available via subscription  
Journal of Bone Marrow Research     Open Access   (Followers: 2)
Journal of Brewing and Distilling     Open Access   (Followers: 2)
Journal of Cell and Animal Biology     Open Access  
Journal of Cell Biology and Genetics     Open Access   (Followers: 2)
Journal of Clinical Microbiology     Hybrid Journal   (Followers: 32)
Journal of Clinical Pathology     Full-text available via subscription   (Followers: 10)
Journal of Extracellular Vesicles     Open Access   (Followers: 4)
Journal of Food Microbiology     Open Access   (Followers: 5)
Journal of General and Molecular Virology     Open Access   (Followers: 1)
Journal of Genes and Cells     Open Access   (Followers: 1)
Journal of Global Antimicrobial Resistance     Hybrid Journal   (Followers: 2)
Journal of Industrial Microbiology and Biotechnology     Hybrid Journal   (Followers: 16)
Journal of Medical Microbiology     Full-text available via subscription   (Followers: 5)
Journal of Microbiological Methods     Hybrid Journal   (Followers: 3)
Journal of Microbiology     Hybrid Journal   (Followers: 8)
Journal of Microbiology and Antimicrobials     Open Access   (Followers: 2)
Journal of Microbiology Research     Open Access   (Followers: 6)
Journal of Micropalaeontology     Hybrid Journal   (Followers: 7)
Journal of Molecular Biochemistry     Open Access   (Followers: 3)
Journal of Molecular Biology Research     Open Access   (Followers: 3)
Journal of Molecular Microbiology and Biotechnology     Full-text available via subscription   (Followers: 14)
Journal of Molecular Psychiatry     Open Access   (Followers: 9)
Journal of Morphology     Hybrid Journal   (Followers: 5)
Journal of Pharmacy & Bioresources     Full-text available via subscription   (Followers: 2)
Journal of Plant Pathology & Microbiology     Open Access   (Followers: 1)
Journal of Proteome Science and Computational Biology     Open Access  
Journal of Regenerative Medicine and Tissue Engineering     Open Access   (Followers: 4)
Journal of The Academy of Clinical Microbiologists     Open Access  
Journal of the American Society of Brewing Chemists     Full-text available via subscription   (Followers: 2)
Journal of the Institute of Brewing     Free   (Followers: 3)
Journal of Tropical Microbiology and Biotechnology     Full-text available via subscription  
Jundishapur Journal of Microbiology     Open Access  
Letters In Applied Microbiology     Hybrid Journal   (Followers: 7)
Macrophage     Open Access  
MAP Kinase     Open Access  
Medical Mycology     Open Access   (Followers: 4)
Memórias do Instituto Oswaldo Cruz     Open Access  
Metagenomics     Unknown  
Methods in Molecular Biology     Hybrid Journal   (Followers: 18)
Microbes and Health     Open Access   (Followers: 1)
Microbes and Infection     Full-text available via subscription   (Followers: 5)
Microbial Biotechnology     Open Access   (Followers: 9)
Microbial Cell Factories     Open Access   (Followers: 7)
Microbial Drug Resistance     Hybrid Journal   (Followers: 4)
Microbial Ecology     Hybrid Journal   (Followers: 11)
Microbial Ecology in Health and Disease     Open Access   (Followers: 1)
Microbial Informatics and Experimentation     Open Access   (Followers: 1)
Microbial Pathogenesis     Hybrid Journal   (Followers: 7)
Microbial Risk Analysis     Full-text available via subscription  
Microbiologia Medica     Open Access   (Followers: 1)
Microbiological Research     Hybrid Journal   (Followers: 6)
Microbiology     Hybrid Journal   (Followers: 15)
Microbiology (SGM)     Full-text available via subscription   (Followers: 19)
Microbiology and Immunology     Hybrid Journal   (Followers: 10)
Microbiology and Molecular Biology Reviews     Hybrid Journal   (Followers: 26)
Microbiology Australia     Hybrid Journal  
Microbiology Discovery     Open Access   (Followers: 2)
Microbiology Indonesia     Open Access  
Microbiology Research     Open Access   (Followers: 7)
MicrobiologyOpen     Open Access   (Followers: 2)
Microbiome     Hybrid Journal   (Followers: 9)
Microbiome Science and Medicine     Open Access   (Followers: 3)
Microorganisms     Open Access   (Followers: 2)
MicroRNA     Hybrid Journal   (Followers: 1)
Molecular and Cellular Therapies     Open Access  
Molecular Biology and Genetic Engineering     Open Access   (Followers: 2)
Molecular Biology Research Communications     Open Access   (Followers: 1)
Molecular Genetics and Metabolism Reports     Open Access   (Followers: 3)
Molecular Genetics, Microbiology and Virology     Hybrid Journal   (Followers: 7)
Molecular Imaging     Open Access  
Molecular Imaging and Biology     Hybrid Journal   (Followers: 2)
Molecular Medicine     Open Access   (Followers: 3)
Molecular Medicine Reports     Full-text available via subscription   (Followers: 4)
Molecular Microbiology     Hybrid Journal   (Followers: 33)
Molecular Neuropsychiatry     Full-text available via subscription  
Molecular Oral Microbiology     Partially Free   (Followers: 3)

        1 2 | Last

Journal Cover International Journal of Food Microbiology
  [SJR: 1.64]   [H-I: 142]   [13 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0168-1605
   Published by Elsevier Homepage  [3049 journals]
  • Optimization of PMAxx pretreatment to distinguish between human norovirus
           with intact and altered capsids in shellfish and sewage samples
    • Authors: Walter Randazzo; Mohammad Khezri; Joanna Ollivier; Françoise S. Le Guyader; Jesús Rodríguez-Díaz; Rosa Aznar; Gloria Sánchez
      Pages: 1 - 7
      Abstract: Publication date: 2 February 2018
      Source:International Journal of Food Microbiology, Volume 266
      Author(s): Walter Randazzo, Mohammad Khezri, Joanna Ollivier, Françoise S. Le Guyader, Jesús Rodríguez-Díaz, Rosa Aznar, Gloria Sánchez
      Shellfish contamination by human noroviruses (HuNoVs) is a serious health and economic problem. Recently an ISO procedure based on RT-qPCR for the quantitative detection of HuNoVs in shellfish has been issued, but these procedures cannot discriminate between inactivated and potentially infectious viruses. The aim of the present study was to optimize a pretreatment using PMAxx to better discriminate between intact and heat-treated HuNoVs in shellfish and sewage. To this end, the optimal conditions (30min incubation with 100μM of PMAxx and 0.5% of Triton, and double photoactivation) were applied to mussels, oysters and cockles artificially inoculated with thermally-inactivated (99°C for 5min) HuNoV GI and GII. This pretreatment reduced the signal of thermally-inactivated HuNoV GI in cockles and HuNoV GII in mussels by >3 log. Additionally, this pretreatment reduced the signal of thermally-inactivated HuNoV GI and GII between 1 and 1.5 log in oysters. Thermal inactivation of HuNoV GI and GII in PBS, sewage and bioaccumulated oysters was also evaluated by the PMAxx-Triton pretreatment. Results showed significant differences between reductions observed in the control and PMAxx-treated samples in PBS following treatment at 72 and 95°C for 15min. In sewage, the RT-qPCR signal of HuNoV GI was completely removed by the PMAxx pretreatment after heating at 72 and 95°C, while the RT-qPCR signal for HuNoV GII was completely eliminated only at 95°C. Finally, the PMAxx-Triton pretreatment was applied to naturally contaminated sewage and oysters, resulting in most of the HuNoV genomes quantified in sewage and oyster samples (12 out of 17) corresponding to undamaged capsids. Although this procedure may still overestimate infectivity, the PMAxx-Triton pretreatment represents a step forward to better interpret the quantification of intact HuNoVs in complex matrices, such as sewage and shellfish, and it could certainly be included in the procedures based on RT-qPCR.

      PubDate: 2017-12-01T02:53:27Z
      DOI: 10.1016/j.ijfoodmicro.2017.11.011
      Issue No: Vol. 266 (2017)
       
  • Isolation and characterization of polyvalent bacteriophages infecting
           multi drug resistant Salmonella serovars isolated from broilers in Egypt
    • Authors: Mayada Mahmoud; Ahmed Askora; Ahmed Barakat Barakat; Omar El-Farouk Rabie; Sayed Emam Hassan
      Pages: 8 - 13
      Abstract: Publication date: 2 February 2018
      Source:International Journal of Food Microbiology, Volume 266
      Author(s): Mayada Mahmoud, Ahmed Askora, Ahmed Barakat Barakat, Omar El-Farouk Rabie, Sayed Emam Hassan
      In this study, we isolated and characterized three phages named as Salmacey1, Salmacey2 and Salmacey3, infecting multi drug resistant Salmonella serovars isolated from broilers in Egypt. The most prevalent Salmonella serovars were S. typhimurium, S. enteritidis, and S. kentucky. All these Salmonella serovars were found to be resistant to more than two of the ten antimicrobial agents tested. Only S. kentucky was found to be resistant to seven antimicrobial agents. Examination of these phage particles by transmission electron microscopy (TEM), demonstrated that two phages (Salmacey1, Salmacey2) were found to belong to family Siphoviridae, and Salmacey3 was assigned to the family Myoviridae. The results of host range assay revealed that these bacteriophages were polyvalent and thus capable of infecting four strains of Salmonella serovars and Citrobacter freundii. Moreover, the two phages (Salmacey1, Salmacey2) had a lytic effect on Enterobacter cloacae and Salmacey3 was able to infect E. coli. All phages could not infect S. para Typhi, Staphylococus aureus and Bacillus cereus. One-step growth curves of bacteriophages revealed that siphovirus phages (Salmacey1, Salmacey2) have burst size (80 and 90pfu per infected cell with latent period 35min and 40min respectively), and for the myovirus Salmacey3 had a burst size 110pfu per infected cell with latent period 60min. Molecular analyses indicated that these phages contained double-stranded DNA genomes. The lytic activity of the phages against the most multidrug resistant serovars S. kentucky as host strain was evaluated. The result showed that these bacteriophages were able to completely stop the growth of S. kentucky in vitro. These results suggest that phages have a high potential for phage application to control Salmonella serovars isolated from broilers in Egypt.

      PubDate: 2017-12-01T02:53:27Z
      DOI: 10.1016/j.ijfoodmicro.2017.11.009
      Issue No: Vol. 266 (2017)
       
  • Microbial diversity of consumption milk during processing and storage
    • Authors: Davide Porcellato; Marina Aspholm; Siv Borghild Skeie; Marte Monshaugen; Johanne Brendehaug; Hilde Mellegård
      Pages: 21 - 30
      Abstract: Publication date: 2 February 2018
      Source:International Journal of Food Microbiology, Volume 266
      Author(s): Davide Porcellato, Marina Aspholm, Siv Borghild Skeie, Marte Monshaugen, Johanne Brendehaug, Hilde Mellegård
      Bovine milk contains a complex microbial community that affects the quality and safety of the product. Detailed knowledge of this microbiota is, therefore, of importance for the dairy industry. In this study, the bacterial composition of consumption milk was assessed during different stages in the production line and throughout the storage in cartons by using culturing techniques and 16S rRNA marker gene sequencing. Monthly samples from two dairies were analyzed to capture the seasonal variations in the milk microbiota. Although there was a core microbiota present in milk samples from both dairies, the composition of the bacterial communities were significantly influenced by sampling month, processing stage and storage temperature. Overall, a higher abundance of operational taxonomic units (OTUs) within the order Bacillales was detected in samples of raw and pasteurized milk from the spring and summer months, while Pseudomonadales and Lactobacillales OTUs were predominant in the winter months. OTUs belonging to the order Lactobacillales, Pseudomonadales, Clostridiales and Bacillales were significantly more abundant in milk samples taken immediately after pasteurization compared to raw milk samples. During storage of milk in cartons at 4°C, the bacterial composition remained stable throughout the product shelf life, while storage at 8°C significantly increased the abundance of OTUs belonging to the genus Bacillus and the plate count levels of presumptive Bacillus cereus. The knowledge obtained in this work will be useful to the dairy industry during their quality assurance work and risk assessment practices.

      PubDate: 2017-12-01T02:53:27Z
      DOI: 10.1016/j.ijfoodmicro.2017.11.004
      Issue No: Vol. 266 (2017)
       
  • Effect of vacuum and modified atmosphere packaging on the microbiological,
           chemical and sensory properties of tropical red drum (Sciaenops ocellatus)
           fillets stored at 4°C
    • Authors: Adèle Silbande; Sandra Adenet; Christine Chopin; Josiane Cornet; Juliette Smith-Ravin; Katia Rochefort; Françoise Leroi
      Pages: 31 - 41
      Abstract: Publication date: 2 February 2018
      Source:International Journal of Food Microbiology, Volume 266
      Author(s): Adèle Silbande, Sandra Adenet, Christine Chopin, Josiane Cornet, Juliette Smith-Ravin, Katia Rochefort, Françoise Leroi
      Aims The effect of vacuum (VP – 4°C) and CO2/N2–atmosphere (MAP – 4°C) packaging on the quality of red drum fillets compared with whole gutted iced fish was investigated. Methods and results A metagenomic approach, bacterial enumeration and isolation, biochemical and sensory analyses were carried out. The organoleptic rejection of whole fish was observed at day 15 whereas VP and MAP fillets appeared unacceptable only after 29days. At these dates, total mesophilic counts reached 107–108 CFU g−1. According to Illumina MiSeq sequencing, Arthrobacter, Chryseobacterium, Brevibacterium, Staphylococcus and Kocuria were the main genera of the fresh red drum fillets. At the sensory rejection time, lactic acid bacteria (LAB), particularly Carnobacterium sp., dominated the microbiota of both types of packaging. The pH value of fresh samples was between 5.96 and 6.37 and did not vary greatly in all trials. Total volatile basic nitrogen (TVBN) and trimethylamine (TMA) concentrations were low and not represent reliable indicators of the spoilage, contrary to some biogenic amines (cadaverine, putrescine and tyramine). Conclusion Chilled packed fillets of red drum have an extended shelf-life compared to whole gutted iced fish. Overall, few differences in sensory and microbial quality were observed between the VP and MAP samples. Significance and impact of the study Next-Generation Sequencing (NGS) provided data on the microbiota of a tropical fish.

      PubDate: 2017-12-01T02:53:27Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.015
      Issue No: Vol. 266 (2017)
       
  • Novel insights into microbial community dynamics during the fermentation
           of Central European ice wine
    • Authors: Mária Bučková; Andrea Puškárová; Katarína Ženišová; Lucia Kraková; Ľubica Piknová; Tomáš Kuchta; Domenico Pangallo
      Pages: 42 - 51
      Abstract: Publication date: 2 February 2018
      Source:International Journal of Food Microbiology, Volume 266
      Author(s): Mária Bučková, Andrea Puškárová, Katarína Ženišová, Lucia Kraková, Ľubica Piknová, Tomáš Kuchta, Domenico Pangallo
      Culture-dependent and culture-independent strategies were applied to investigate the microbiota of autumn undamaged and damaged berries, winter berries and ice wine must samples of Grüner Veltliner (Veltlínske zelené) from Small Carpathian wine-producing region. One hundred twenty-six yeasts and 242 bacterial strains isolated from several microbiological media (YPD, PDA, R2A, GYC, MRS and MRS-T) were clustered by ITS-PCR and subsequent Qiaxcel electrophoresis. Representatives of each cluster were identified by sequencing. The extracellular hydrolytic properties and intracellular activities of esterase and β-glucosidase of isolates were assayed. The culture-independent approach permitted the analysis of extracted DNA and RNA coupling DGGE fingerprinting with construction of clone libraries (bacterial and fungal; DGGE-cloning). The combination of the two approaches provided comprehensive data that evidenced the presence of a complex microbiota in each analyzed sample. RNA and DNA analyses facilitated differentiation of living microorganisms from the entire microbiota. Diverse microbial communities colonized the autumn and winter berries. Generally, the combination of results obtained by the methods suggested that the must samples contained mainly Saccharomyces cerevisiae, Metschnikowia spp., Hanseniaspora uvarum, Lactococcus lactis and Leuconostoc spp. The strains exhibited interesting esterase and β-glucosidase properties, which are important for aroma formation in wine. Fermentation strategies utilising these microorganisms, could be attempted in the future in order to modulate the ice wine characteristics.

      PubDate: 2017-12-01T02:53:27Z
      DOI: 10.1016/j.ijfoodmicro.2017.11.010
      Issue No: Vol. 266 (2017)
       
  • The effect of essential oils on microbial composition and quality of grass
           carp (Ctenopharyngodon idellus) fillets during chilled storage
    • Authors: Zhan Huang; Xiaochang Liu; Shiliang Jia; Longteng Zhang; Yongkang Luo
      Pages: 52 - 59
      Abstract: Publication date: 2 February 2018
      Source:International Journal of Food Microbiology, Volume 266
      Author(s): Zhan Huang, Xiaochang Liu, Shiliang Jia, Longteng Zhang, Yongkang Luo
      Antimicrobial and antioxidant effects of essential oils (oregano, thyme, and star anise) on microbial composition and quality of grass carp fillets were investigated. Essential oils treatment was found to be effective in inhibiting microbial growth, delaying lipid oxidation, and retarding the increase of TVB-N, putrescine, hypoxanthine, and K-value. Based on sensory analysis, shelf-life of grass carp fillets was 6days for control and 8days for treatment groups. Among the essential oils, oregano essential oil exhibited the highest antimicrobial and antioxidant activities. GC-MS analysis of essential oils components revealed that carvacrol (88.64%) was the major component of oregano essential oil. According to the results of high-throughput sequencing, Aeromonas, Glutamicibacter, and Aequorivita were the predominant microbiota in fresh control samples. However, oregano essential oil decreased the relative abundance of Aeromonas, while thyme and star anise essential oils decreased the relative abundance of Glutamicibacter and Aequorivita in fresh treated samples. The microbial composition of both control and treatment groups became less diverse as storage time increased. Aeromonas and Pseudomonas were dominant in spoiled samples and contributed to fish spoilage. Compared to the control, essential oils effectively inhibited the growth of Aeromonas and Shewanella in grass carp fillets during chilled storage.

      PubDate: 2017-12-01T02:53:27Z
      DOI: 10.1016/j.ijfoodmicro.2017.11.003
      Issue No: Vol. 266 (2017)
       
  • Preservation of large yellow croaker (Pseudosciaena crocea) by Coagulin
           L1208, a novel bacteriocin produced by Bacillus coagulans L1208
    • Authors: Linglin Fu; Chong Wang; Xinming Ruan; Gang Li; Yu Zhao; Yanbo Wang
      Pages: 60 - 68
      Abstract: Publication date: 2 February 2018
      Source:International Journal of Food Microbiology, Volume 266
      Author(s): Linglin Fu, Chong Wang, Xinming Ruan, Gang Li, Yu Zhao, Yanbo Wang
      Large yellow croaker (Pseudosciaena crocea) is a cultivated fish of great economic importance and abundant nutritional value. However, due to its high protein and water contents, it is susceptible to decomposition, leading to considerable economic loss and adverse effects on consumer health. Here, we assessed the function of the bacterial strain Bacillus coagulans L1208 (Bcoa) in preserving large yellow croaker during storage at 4°C and found that Bcoa elongates the shelf-life significantly. Further investigations showed that Bcoa prolongs the storage time mainly by suppressing the growth of spoilage bacteria. Moreover, a novel bacteriocin, designated as Coagulin L1208 and produced by Bcoa, was purified and identified by N-terminal sequencing. Finally, the activity of Coagulin L1208 for suppressing spoilage bacteria during the preservation of large yellow croaker was assessed. Our results reveal the mechanism by which Bcoa aids the preservation of large yellow croaker and identify Coagulin L1208 as a potential novel antiseptic.

      PubDate: 2017-12-01T02:53:27Z
      DOI: 10.1016/j.ijfoodmicro.2017.11.012
      Issue No: Vol. 266 (2017)
       
  • The antibacterial activity of clove oil/chitosan nanoparticles embedded
           gelatin nanofibers against Escherichia coli O157:H7 biofilms on cucumber
    • Authors: Haiying Cui; Mei Bai; Marwan M.A. Rashed; Lin Lin
      Pages: 69 - 78
      Abstract: Publication date: 2 February 2018
      Source:International Journal of Food Microbiology, Volume 266
      Author(s): Haiying Cui, Mei Bai, Marwan M.A. Rashed, Lin Lin
      This study aims to evaluate the antibacterial activity of clove oil-loaded chitosan nanoparticles (CO@CNPs) and gelatin electrospun nanofibers against Escherichia coli O157:H7 (E. coli O157:H7) biofilms on cucumbers. The optimal CO@CNPs were prepared when the initial concentration of clove oil (CO) was 2.5mg/mL according to the ionic crosslinking method. CO@CNPs showed high antibacterial activity against E. coli O157:H7 biofilms. After 8h treatment, almost 99.98% reduction in E. coli O157:H7 population was achieved when CO@CNPs were applied at 30% (w/v). Subsequently, the prepared CO@CNPs were incorporated successfully within gelatin nanofibers by electrospinning. After 9mg/mL gelatin/CO@CNPs treatment for 24h, the population of E. coli O157:H7 biofilm reduced by about 99.99% in vitro. Further, the application of gelatin/CO@CNPs nanofibers on cucumber against E. coli O157:H7 biofilm was evaluated as well. After 6mg/mL and 9mg/mL gelatin/CO@CNPs nanofibers treatment at 12°C for 4days, 4.28 and 4.97 log10 reductions of E. coli O157:H7 biofilm in population were observed, respectively. Finally, the sensory evaluation results implied that the gelatin/CO@CNPs nanofibers treatment could maintain the color and flavor of cucumber well for >4days.

      PubDate: 2017-12-01T02:53:27Z
      DOI: 10.1016/j.ijfoodmicro.2017.11.019
      Issue No: Vol. 266 (2017)
       
  • Influence of fermentation and other processing steps on the folate content
           of a traditional African cereal-based fermented food
    • Authors: Fabien Saubade; Youna M. Hemery; Isabelle Rochette; Jean-Pierre Guyot; Christèle Humblot
      Pages: 79 - 86
      Abstract: Publication date: 2 February 2018
      Source:International Journal of Food Microbiology, Volume 266
      Author(s): Fabien Saubade, Youna M. Hemery, Isabelle Rochette, Jean-Pierre Guyot, Christèle Humblot
      Folate deficiency can cause a number of diseases including neural tube defects and megaloblastic anemia, and still occurs in both developed and developing countries. Cereal-based food products are staple foods in many countries, and may therefore be useful sources of folate. The production of folate by microorganisms has been demonstrated in some cereal-based fermented foods, but has never been studied in a traditional African cereal based food spontaneously fermented. The microbiota of ben-saalga, a pearl-millet based fermented porridge frequently consumed in Burkina Faso, has a good genetic potential for the synthesis of folate, but the folate content of ben-saalga is rather low, suggesting that folate is lost during the different processing steps. The aim of this study was therefore to monitor changes in folate content during the different steps of preparing ben-saalga, from pearl-millet grains to porridge. Traditional processing involves seven different steps: washing, soaking, grinding, kneading, sieving, (spontaneous) fermentation, and cooking. Two type of porridge were prepared, one using a process adapted from the traditional process, the other a modified process based on fermentation by backslopping. Dry matter and total folate contents were measured at each step, and a mass balance assessment was performed to follow folate losses and gains. Folate production was observed during the soaking of pearl-millet grains (+26% to +79%), but the folate content of sieved batters (2.5 to 3.4μg/100g fresh weight) was drastically lower than that of milled soaked grains (17.3 to 19.4μg/100g FW). The final folate content of the porridges was very low (1.5 to 2.4μg/100g FW). The fermentation had no significant impact on folate content, whatever the duration and the process used. This study led to a better understanding of the impact on folate of the different processing steps involved in the preparation of ben-saalga.

      PubDate: 2017-12-01T02:53:27Z
      DOI: 10.1016/j.ijfoodmicro.2017.11.015
      Issue No: Vol. 266 (2017)
       
  • Control of anthracnose caused by Colletotrichum species in guava, mango
           and papaya using synergistic combinations of chitosan and Cymbopogon
           citratus (D.C. ex Nees) Stapf. essential oil
    • Authors: Priscila Dinah Lima Oliveira; Kataryne Árabe Rimá de Oliveira; Willie Anderson dos Santos Vieira; Marcos Paz Saraiva Câmara; Evandro Leite de Souza
      Pages: 87 - 94
      Abstract: Publication date: 2 February 2018
      Source:International Journal of Food Microbiology, Volume 266
      Author(s): Priscila Dinah Lima Oliveira, Kataryne Árabe Rimá de Oliveira, Willie Anderson dos Santos Vieira, Marcos Paz Saraiva Câmara, Evandro Leite de Souza
      This study assessed the efficacy of chitosan (Chi) and Cymbopogon citratus (D.C. ex Nees) Stapf. essential oil (CCEO) combinations to control the mycelial growth of five pathogenic Colletotrichum species (C. asianum, C. siamense, C. fructicola, C. tropicale and C. karstii) in vitro, as well as the anthracnose development in guava (Psidium guajava L.) cv. Paluma, mango (Mangifera indica L.) cv. Tommy Atkins and papaya (Carica papaya L.) cv. Papaya artificially inoculated with these species. Combinations of Chi (2.5, 5 or 7.5mg/mL) and CCEO (0.15, 0.3, 0.6 or 1.25μL/mL) inhibited the mycelial growth of all tested fungal species in vitro. Examined Chi-CCEO combinations showed additive or synergistic interactions to inhibit the target Colletotrichum species based on the Abbott index. Coatings formed by synergistic Chi (5mg/mL) and CCEO (0.15, 0.3 or 0.6μL/mL) combinations decreased anthracnose lesion development in guava, mango and papaya inoculated with any of the tested Colleotrichum species during storage. Overall, anthracnose lesion development inhibition in fruit coated with synergistic Chi-CCEO combinations was higher than that observed in fruit treated with synthetic fungicides. These results show that the application of coatings formed by Chi-CCEO synergistic combinations could be effective to control postharvest anthracnose development in fruit.

      PubDate: 2017-12-01T02:53:27Z
      DOI: 10.1016/j.ijfoodmicro.2017.11.018
      Issue No: Vol. 266 (2017)
       
  • Abundance and potential contribution of Gram-negative cheese rind bacteria
           from Austrian artisanal hard cheeses
    • Authors: Stephan Schmitz-Esser; Monika Dzieciol; Eva Nischler; Elisa Schornsteiner; Othmar Bereuter; Evelyne Mann; Martin Wagner
      Pages: 95 - 103
      Abstract: Publication date: 2 February 2018
      Source:International Journal of Food Microbiology, Volume 266
      Author(s): Stephan Schmitz-Esser, Monika Dzieciol, Eva Nischler, Elisa Schornsteiner, Othmar Bereuter, Evelyne Mann, Martin Wagner
      Many different Gram-negative bacteria have been shown to be present on cheese rinds. Their contribution to cheese ripening is however, only partially understood until now. Here, cheese rind samples were taken from Vorarlberger Bergkäse (VB), an artisanal hard washed-rind cheese from Austria. Ripening cellars of two cheese production facilities in Austria were sampled at the day of production and after 14, 30, 90 and 160days of ripening. To obtain insights into the possible contribution of Advenella, Psychrobacter, and Psychroflexus to cheese ripening, we sequenced and analyzed the genomes of one strain of each genus isolated from VB cheese rinds. Additionally, quantitative PCRs (qPCRs) were performed to follow the abundance of Advenella, Psychrobacter, and Psychroflexus on VB rinds during ripening in both facilities. qPCR results showed that Psychrobacter was most abundant on cheese rinds and the abundance of Advenella decreased throughout the first month of ripening and increased significantly after 30days of ripening (p<0.01). Psychrobacter and Psychroflexus increased significantly during the first 30 ripening days (p<0.01), and decreased to their initial abundance during the rest of the ripening time (p<0.05). Genome sequencing resulted in 17 to 27 contigs with assembly sizes of 2.7 Mbp for Psychroflexus, 3 Mbp for Psychrobacter, and 4.3 Mbp for Advenella. Our results reveal that each genome harbors enzymes shown to be important for cheese ripening in other bacteria such as: Cystathionine/Methionine beta or gamma-lyases, many proteases and peptidases (including proline iminopeptidases), aminotransferases, and lipases. Thus, all three isolates have the potential to contribute positively to cheese ripening. In conclusion, the three species quantified were stable community members throughout the ripening process and their abundance on cheese rinds together with the results from genome sequencing suggest an important contribution of these bacteria to cheese ripening.

      PubDate: 2017-12-01T02:53:27Z
      DOI: 10.1016/j.ijfoodmicro.2017.11.013
      Issue No: Vol. 266 (2017)
       
  • A novel non-dairy beverage from durian pulp fermented with selected
           probiotics and yeast
    • Authors: Yuyun Lu; Satya Dwi Putra; Shao-Quan Liu
      Pages: 1 - 8
      Abstract: Publication date: 16 January 2018
      Source:International Journal of Food Microbiology, Volume 265
      Author(s): Yuyun Lu, Satya Dwi Putra, Shao-Quan Liu
      This study investigated the effects of sequential inoculation (Seq-I) of Bifidobacterium animalis subsp. lactis or Lactobacillus casei with yeast Williopsis saturnus on durian pulp fermentation. Seq-I of W. saturnus following B. animalis subsp. lactis did not bring about any significant differences compared to the B. animalis subsp. lactis monoculture due to the sharp early death of W. saturnus soon after inoculation. However, Seq-I of W. saturnus significantly enhanced the survival of L. casei and improved the utilization of fructose and glucose compared to L. casei monoculture. In addition, there were significant differences in the metabolism of organic acids especially for lactic acid and succinic acid. Furthermore, Seq-I produced significantly higher levels of volatile compounds including alcohols (ethanol and 2-phenylethyl alcohol) and acetate esters (2-phenylethyl acetate, isoamyl acetate and ethyl acetate), which would positively contribute to the flavour notes. Although the initial volatile sulphur compounds were reduced to trace levels after fermentation, but the durian odour still remained. This study suggests that the use of probiotics and W. saturnus to ferment durian pulp could act as a potential avenue to develop a novel non-dairy durian-based functional beverage to deliver probiotics.

      PubDate: 2017-11-05T12:45:39Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.030
      Issue No: Vol. 265 (2017)
       
  • A comparison of bioinformatic approaches for 16S rRNA gene profiling of
           food bacterial microbiota
    • Authors: Francesca De Filippis; Eugenio Parente; Teresa Zotta; Danilo Ercolini
      Pages: 9 - 17
      Abstract: Publication date: 16 January 2018
      Source:International Journal of Food Microbiology, Volume 265
      Author(s): Francesca De Filippis, Eugenio Parente, Teresa Zotta, Danilo Ercolini
      The different pipelines that may be used in 16S rRNA gene profiling of bacterial communities are known to have a significant impact on alpha and beta diversity measures and this may prevent direct comparison of results obtained in studies using different bioinformatic approaches to analyse raw sequences. To evaluate the feasibility of meta-studies on food bacterial communities, we compared four analysis procedures, varying in OTU picking and taxonomy assignment strategies. A closed reference OTU picking resulted in the most divergent results in terms of both alpha and beta diversity, compared to open reference methods. Nevertheless, when OTUs were collapsed at the genus level, a high correlation was obtained among the estimated abundances of taxa for most studies. Aggregation of samples by their nature and occurrence of food spoilage or fermentation resulted in a very similar classification using two beta diversity analysis methods. We conclude that comparisons of data obtained from different studies are feasible at the genus level, when the same OTU picking strategy is used. Finally, we provide a new version of FoodMicrobionet (Parente et al., 2016), including data from 26 recent studies on food bacterial communities, together with R scripts allowing both the extraction of data in formats which can be used in several analysis tools (including the R package phyloseq and the Cytoscape app CoNet) and the statistical and graphical analysis using common alpha- and beta-diversity analysis methods.

      PubDate: 2017-11-19T01:18:34Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.028
      Issue No: Vol. 265 (2017)
       
  • Volatile organic compounds from Wickerhamomyces anomalus, Metschnikowia
           pulcherrima and Saccharomyces cerevisiae inhibit growth of decay causing
           fungi and control postharvest diseases of strawberries
    • Authors: Lucia Oro; Erica Feliziani; Maurizio Ciani; Gianfranco Romanazzi; Francesca Comitini
      Pages: 18 - 22
      Abstract: Publication date: 16 January 2018
      Source:International Journal of Food Microbiology, Volume 265
      Author(s): Lucia Oro, Erica Feliziani, Maurizio Ciani, Gianfranco Romanazzi, Francesca Comitini
      The effectiveness of Wickerhamomyces anomalus, Metschnikowia pulcherrima and Saccharomyces cerevisiae as biocontrol agents on postharvest decay of strawberry (Fragaria x ananassa, cv. ‘Alba’) fruit, and their inhibitory activities on some decay-causing fungi were evaluated. Volatile organic compounds from these yeasts decreased mycelial growth of Botrytis cinerea by 69%, and by less for Monilinia fructicola, Alternaria alternata, Aspergillus carbonarius, Penicillium digitatum, Cladosporium spp., and Colletotrichum spp. Strawberry fruit exposed to 6-day-old liquid cultures of W. anomalus, M. pulcherrima and S. cerevisiae for 48h showed 89%, 40%, and 32% reductions, respectively, in gray mold McKinney Index. Vapours of ethyl acetate, the main volatile organic compound of these yeasts, completely inhibited B. cinerea growth at 8.97mg/cm3, and suppressed gray mold on strawberry fruit at 0.718mg/cm3. The biocontrol activities of these yeasts can be ascribed to ethyl acetate, which can be used for control of postharvest gray mold of strawberry fruit.

      PubDate: 2017-11-05T12:45:39Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.027
      Issue No: Vol. 265 (2017)
       
  • Staphylococcal food poisoning caused by Staphylococcus argenteus harboring
           staphylococcal enterotoxin genes
    • Authors: Yuki Wakabayashi; Kaoru Umeda; Shinya Yonogi; Hiromi Nakamura; Kaori Yamamoto; Yuko Kumeda; Kentaro Kawatsu
      Pages: 23 - 29
      Abstract: Publication date: 16 January 2018
      Source:International Journal of Food Microbiology, Volume 265
      Author(s): Yuki Wakabayashi, Kaoru Umeda, Shinya Yonogi, Hiromi Nakamura, Kaori Yamamoto, Yuko Kumeda, Kentaro Kawatsu
      Staphylococcal food poisoning (SFP) is caused by staphylococcal enterotoxins (SEs) preformed in food materials. SE genes are encoded on mobile genetic elements and are widely found across Staphylococcus species including S. argenteus, although most SFP cases are caused by S. aureus. S. argenteus, recently discriminated from S. aureus as a novel species, are non-pigmented staphylococci phenotypically related to S. aureus. In 2014 and 2015, two independent food poisoning cases occurred in Osaka, Japan, in which non-pigmented staphylococci were predominantly isolated. Several enterotoxin genes (seb, seg, sei, sem, sen, seo, and selu2) were found in their genome and the production of SEB was confirmed by reverse passive agglutination tests. The non-pigmented isolates from patients, food handlers, food, and cooking utensils all produced the same pulsed-field gel electrophoresis pattern. These non-pigmented isolates were coagulase-positive and biochemically identical to S. aureus. We performed further genetic analysis using nucA sequencing and multi-locus sequence typing, and identified these isolates as S. argenteus. We also found that seb was encoded on the Staphylococcus aureus pathogenicity island, while seg, sei, sem, sen, seo, and selu2 were encoded on the enterotoxin gene cluster. From these results, we concluded that the two food poisoning outbreaks were SFP cases caused by S. argenteus harboring SE genes.

      PubDate: 2017-11-19T01:18:34Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.022
      Issue No: Vol. 265 (2017)
       
  • The genetic basis underlying variation in production of the flavour
           compound diacetyl by Lactobacillus rhamnosus strains in milk
    • Authors: Raquel Lo; Van Thi Thuy Ho; Nidhi Bansal; Mark S. Turner
      Pages: 30 - 39
      Abstract: Publication date: 16 January 2018
      Source:International Journal of Food Microbiology, Volume 265
      Author(s): Raquel Lo, Van Thi Thuy Ho, Nidhi Bansal, Mark S. Turner
      Diacetyl and the closely related compound acetoin impart desirable buttery flavour and odour to many foods including cheese and are generated through the metabolism of citrate by lactic acid bacteria (LAB). To increase the levels of these compounds, adjunct cultures capable of producing them can be added to cheese fermentations. In this study, we compared the diacetyl and acetoin producing abilities of 13 Lactobacillus rhamnosus strains from cheese sources. Diacetyl and acetoin production was found to be a common feature of Lb. rhamnosus grown in milk, with 12 strains producing these compounds. Whole genome sequencing of four strains revealed that genes encoding the citrate metabolising pathway present in other LAB are conserved in Lb. rhamnosus. One strain was, however, totally defective in diacetyl and acetoin production. This was likely due to an inability to produce the diacetyl/acetoin precursor compound acetolactate resulting from a frameshift mutation in the acetolactate synthase (als) gene. Complementation of this defective strain with a complete als gene from a diacetyl producing strain restored production of diacetyl and acetoin to levels equivalent to naturally high producing strains. Introduction of the same als-containing plasmid into the probiotic Lb. rhamnosus strain GG also increased diacetyl and acetoin levels. In model cheesemaking experiments, the als-complemented strain produced very high levels of diacetyl and acetoin over 35days of ripening. These findings identify the genetic basis for natural variation in production of a key cheese flavour compound in Lb. rhamnosus strains.

      PubDate: 2017-11-11T21:51:08Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.029
      Issue No: Vol. 265 (2017)
       
  • Optimisation of the antifungal potency of the amidated peptide
           H-Orn-Orn-Trp-Trp-NH2 against food contaminants
    • Authors: Thibaut Thery; Yvonne O'Callaghan; Nora O'Brien; Elke K. Arendt
      Pages: 40 - 48
      Abstract: Publication date: 16 January 2018
      Source:International Journal of Food Microbiology, Volume 265
      Author(s): Thibaut Thery, Yvonne O'Callaghan, Nora O'Brien, Elke K. Arendt
      The design of novel efficient antimicrobial peptides (AMPs) faces several issues, such as cost of synthesis, proteolytic stability or cytotoxicity. The identification of key determinants involved in the activity of AMPs, such as cationicity and amphipathicity, allowed the synthesis of short peptides with optimized properties. An ultrashort peptide made of the sequence H-Orn-Orn-Trp-Trp-NH2 (O3TR) showed antifungal activity against several contaminants from food products. This peptide inhibited the growth of the filamentous fungi Fusarium culmorum, Penicillium expansum and Aspergillus niger within a range of concentration of 12.5–50μg/ml. In addition, O3TR inhibited the growth of the yeast Saccharomyces cerevisiae, Zygosaccharomyces bailii, Zygosaccharomyces rouxii, Debaryomyces hansenii and Kluyveromyces lactis within the range 12.5–50μg/ml. A derivative peptide, called C12O3TR, made by the addition of lauric acid at the N-terminus of O3TR was 2- to 8-fold more active than O3TR against every species. In addition to the inhibition of conidial germination, O3TR and C12O3TR killed F. culmorum hyphae at 100 and 50μg/ml respectively. The MIC of the two peptides against F. culmorum and Z. bailii after heat treatment at 100°C for 60 min and within the pH range 3–10, were not changed. However, the activity of O3TR against F.culmorum and Z. bailii was strongly reduced in salt solutions, whereas the lauric acid peptide kept its antifungal activity and resistance to proteolytic digestion. The conjugation with lauric acid reduced the random coiled structure and increased the α-helical content of O3TR. After conjugation with the dye tetramethylrhodamine (TMR), both peptides entered F. culmorum spores. They also both induced permeabilization of F. culmorum hyphae but only C12O3TR permeabilized Z. bailii membrane. In contrast to the lipopeptide, O3TR did not show haemolytic or cytotoxic activity when applied at the concentrations that exhibited antifungal potency. The two peptides were challenged against a yeast cocktail of S. cerevisiae and Z. bailii, and A. niger in different commercial beverages. After 7 days, O3TR was able to inhibit the yeast cocktail in a commercial lager and carbonated drink. Due to its antifungal potency, high stability and low cytotoxicity, the tetrapeptide could represent a promising starting point of a novel food preservative.

      PubDate: 2017-11-11T21:51:08Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.024
      Issue No: Vol. 265 (2017)
       
  • Distribution and incidence of atoxigenic Aspergillus flavus VCG in tree
           crop orchards in California: A strategy for identifying potential
           antagonists, the example of almonds
    • Authors: Adeline Picot; Mark Doster; Md-Sajedul Islam; Kenneth Callicott; Alejandro Ortega-Beltran; Peter Cotty; Themis Michailides
      Pages: 55 - 64
      Abstract: Publication date: 16 January 2018
      Source:International Journal of Food Microbiology, Volume 265
      Author(s): Adeline Picot, Mark Doster, Md-Sajedul Islam, Kenneth Callicott, Alejandro Ortega-Beltran, Peter Cotty, Themis Michailides
      To identify predominant isolates for potential use as biocontrol agents, Aspergillus flavus isolates collected from soils of almond, pistachio and fig orchard in the Central Valley of California were tested for their membership to 16 atoxigenic vegetative compatibility groups (VCGs), including YV36, the VCG to which AF36, an atoxigenic isolate commercialized in the United States as biopesticide, belongs. A surprisingly large proportion of isolates belonged to YV36 (13.3%, 7.2% and 6.6% of the total almond, pistachio and fig populations, respectively), while the percentage of isolates belonging to the other 15 VCGs ranged from 0% to 2.3%. In order to gain a better insight into the structure and diversity of atoxigenic A. flavus populations and to further identify predominant isolates, seventeen SSR markers were then used to genetically characterize AF36, the 15 type-isolates of the VCGs and 342 atoxigenic isolates of the almond population. There was considerable genetic diversity among isolates with a lack of differentiation among micro-geographical regions or years. Since isolates sharing identical SSR profiles from distinct orchards were rare, we separated them into groups of at least 3 closely-related isolates from distinct orchards that shared identical alleles for at least 15 out of the 17 loci. This led to the identification of 15 groups comprising up to 24 closely-related isolates. The group which contained the largest number of isolates were members of YV36 while five groups were also found to be members of our studied atoxigenic VCGs. These results suggest that these 15 groups, and AF36 in particular, are well adapted to various environmental conditions in California and to tree crops and, as such, are good candidates for use as biocontrol agents.

      PubDate: 2017-11-11T21:51:08Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.023
      Issue No: Vol. 265 (2017)
       
  • Capture and detection of Staphylococcus aureus with dual labeled aptamers
           to cell surface components
    • Authors: Shylaja Ramlal; Bhairab Mondal; Padma Sudharani Lavu; Bhavanashri N.; Joseph Kingston
      Pages: 74 - 83
      Abstract: Publication date: 16 January 2018
      Source:International Journal of Food Microbiology, Volume 265
      Author(s): Shylaja Ramlal, Bhairab Mondal, Padma Sudharani Lavu, Bhavanashri N., Joseph Kingston
      In the present study, a high throughput whole cell SELEX method has been applied successfully in selecting specific aptamers against whole cells of Staphylococcus aureus, a potent food poisoning bacterium. A total ten rounds of SELEX and three rounds of intermittent counter SELEX, was performed to obtain specific aptamers. Obtained oligonucleotide pool were cloned, sequenced and then grouped into different families based on their primary sequence homology and secondary structure similarity. FITC labeled sequences from different families were selected for further characterization via flow cytometry analysis. The dissociation constant (K d) values of specific and higher binders ranged from 34 to 128nM. Binding assays to assess the selectivity of aptamer RAB10, RAB 20, RAB 28 and RAB 35 demonstrated high affinity against S. aureus and low binding affinity for other bacteria. To demonstrate the potential use of the aptamer a sensitive dual labeled sandwich detection system was developed using aptamer RAB10 and RAB 35 with a detection limit of 102 CFU/mL. Furthermore detection from mixed cell population and spiked sample emphasized the robustness as well as applicability of the developed method. Altogether, the established assay could be a reliable detection tool for the routine investigation of Staphylococcus aureus in samples from food and clinical sources.

      PubDate: 2017-11-11T21:51:08Z
      DOI: 10.1016/j.ijfoodmicro.2017.11.002
      Issue No: Vol. 265 (2017)
       
  • Quantification of Lactobacillus paracasei viable cells in probiotic
           yoghurt by propidium monoazide combined with quantitative PCR
    • Authors: Mirella Crhistine Scariot; Gustavo Luiz Venturelli; Elane Schwinden Prudêncio; Ana Carolina Maisonnave Arisi
      Pages: 1 - 7
      Abstract: Publication date: 2 January 2018
      Source:International Journal of Food Microbiology, Volume 264
      Author(s): Mirella Crhistine Scariot, Gustavo Luiz Venturelli, Elane Schwinden Prudêncio, Ana Carolina Maisonnave Arisi
      Propidium monoazide (PMA) coupled with qPCR has been successfully used for specific quantification of viable bacteria cells in diverse matrices food. The present study aimed to develop PMA-qPCR assay for quantification of Lactobacillus paracasei viable cells in probiotic yoghurt. L. paracasei grown in culture medium was submitted to heat treatment at 60°C for different periods of time and probiotic yoghurt containing L. paracasei were prepared and stored at 4°C for 30days. The viable cells were quantified using qPCR and PMA-qPCR assays targeting tuf gene and also by plate counting. Standard curves were prepared and mean efficiency obtained was 94% and 96% (R2 >0.98) to L. paracasei in culture medium and probiotic yoghurt stored one day, respectively. The limit of detection (LOD) for both samples was 104 genome copies, corresponding to 32.1pg of DNA. For viable cells quantification, standard curves Cq versus log CFU were plotted using mean CFU by plate counting of L. paracasei grown in culture medium and probiotic yoghurt. Results obtained for L. paracasei heat-treated cells were concordant by PMA-qPCR and plate count, CFU decreased as the heat treatment time increased, while qPCR count remained constant. L. paracasei enumerations obtained by qPCR for probiotic yoghurt stored one day and 30days were higher than enumerations by PMA-qPCR for the same samples. The plate count values were similar to CFU values obtained by PMA-qPCR. These results showed that PMA-qPCR is a powerful approach compared with culture-dependent methods for quantification of L. paracasei viable cells in yoghurt. PMA-qPCR allowed reliable obtained results much faster than plate counting.

      PubDate: 2017-10-28T12:35:05Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.021
      Issue No: Vol. 264 (2017)
       
  • Prevalence and characteristics of Shiga toxin-producing Escherichia coli
           in finishing pigs: Implications on public health
    • Authors: Wonhee Cha; Pina M. Fratamico; Leah E. Ruth; Andrew S. Bowman; Jacqueline M. Nolting; Shannon D. Manning; Julie A. Funk
      Pages: 8 - 15
      Abstract: Publication date: 2 January 2018
      Source:International Journal of Food Microbiology, Volume 264
      Author(s): Wonhee Cha, Pina M. Fratamico, Leah E. Ruth, Andrew S. Bowman, Jacqueline M. Nolting, Shannon D. Manning, Julie A. Funk
      Shiga toxin-producing Escherichia coli (STEC) are important food-borne pathogens, which can cause serious illnesses, including hemorrhagic colitis and hemolytic uremic syndrome. To study the epidemiology of STEC in finishing pigs and examine the potential risks they pose for human STEC infections, we conducted a longitudinal cohort study in three finishing sites. Six cohorts of pigs (2 cohorts/site, 20 pigs/cohort) were randomly selected, and fecal samples (n =898) were collected every two weeks through their finishing period. Eighty-two pigs (68.3%) shed STEC at least once, and the proportion of STEC-positive pigs varied across sites (50–97.5%) and cohorts (15–100%). Clinically important serotypes, O157:H7 (stx2c , eae) and O26:H11 (stx1a , eae), were recovered from two pigs at sites C and A, respectively. The most common serotype isolated was O59:H21 (stx2e ), which was particularly prevalent in site B as it was recovered from all STEC positive pigs (n =39). Each cohort showed different patterns of STEC shedding, which were associated with the prevalent serotype. The median shedding duration of STEC in pigs was 28days, consistent with our prior study. However, among pigs shedding O59:H21 at least once, pigs in cohort B2 had a significantly longer shedding duration of 42days (P <0.05) compared to other cohorts. Stx2e was the most commonly observed stx variant in finishing pigs (93.9%), in accordance with the previous studies. Stx2e has been reported to be significantly associated with edema disease in pigs, however, the pathogenicity in humans warrants further investigations. Nonetheless, our findings affirm that pigs are an important reservoir for human STEC infections, and that the circulating serotypes in a cohort and site management factors may significantly affect the prevalence of STEC. Molecular characterization of STEC isolates and epidemiological studies to identify risk factors for shedding in pigs are strongly warranted to further address the significance to public health and to develop mitigation strategies.

      PubDate: 2017-11-11T21:51:08Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.017
      Issue No: Vol. 264 (2017)
       
  • Development of a rapid immunochromatographic assay to detect contamination
           of raw oysters with enteropathogenic Vibrio parahaemolyticus
    • Authors: Junko Sakata; Taro Yonekita; Kentaro Kawatsu
      Pages: 16 - 24
      Abstract: Publication date: 2 January 2018
      Source:International Journal of Food Microbiology, Volume 264
      Author(s): Junko Sakata, Taro Yonekita, Kentaro Kawatsu
      Thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH) are major virulence factors of enteropathogenic Vibrio parahaemolyticus. TDH and TRH are bacterial exotoxins, and their presence in culture medium serves as a specific marker for detecting this significant pathogen. Here, we developed and evaluated an immunochromatographic assay (TDH/TRH-ICA) to simultaneously or individually detect TDH and TRH. The TDH/TRH-ICA detected TDH in all broth cultures of 47 V. parahaemolyticus strains carrying tdh. The genes encoding TRH are classified as variants trh1 and trh2, and TRH was detected in all broth cultures of 25 V. parahaemolyticus strains carrying trh1 and certain proportion (5/31) of broth cultures of V. parahaemolyticus strains carrying trh2. In contrast, TDH and TRH were not detected in broth cultures of 12 non-enteropathogenic V. parahaemolyticus strains without tdh and trh. It was difficult to detect TRH2 using the TDH/TRH-ICA. However, TRH2 may not serve as a suitable marker for detecting enteropathogenic V. parahaemolyticus, and evidence indicates that TRH2 may not contribute to enteropathogenesis. Further, a screening method using a combination of TDH/TRH-ICA and SPP medium supplemented with 1.5% NaCl (modified-SPP medium) detected oyster samples artificially spiked with 1.1–22 colony-forming units of enteropathogenic V. parahaemolyticus per 25g of oysters within approximately 8.5h, including the enrichment culture. The assay may serve as a method that facilitates the rapid and easy detection of raw oysters contaminated with enteropathogenic V. parahaemolyticus.

      PubDate: 2017-11-11T21:51:08Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.016
      Issue No: Vol. 264 (2017)
       
  • High load of hepatitis E viral RNA in pork livers but absence in pork
           muscle at French slaughterhouses
    • Authors: C. Feurer; A. Le Roux; R. Rossel; E. Barnaud; M. Dumarest; P. Garry; N. Pavio
      Pages: 25 - 30
      Abstract: Publication date: 2 January 2018
      Source:International Journal of Food Microbiology, Volume 264
      Author(s): C. Feurer, A. Le Roux, R. Rossel, E. Barnaud, M. Dumarest, P. Garry, N. Pavio
      Pork ham muscle can be contaminated with HEV via blood vessels during viremia and represents a possible source of human contamination via the consumption of dried ham. This study evaluated the prevalence of HEV RNA in pork ham muscles and pork livers at slaughterhouses. Serology was determined on the corresponding serum samples. The apparent individual seroprevalence rate in the 49 pig farms studied was 59% [55.5%–61.4%]. None of the 1134 ham muscles tested was positive for the presence of HEV. HEV prevalence in paired liver samples was 2.8% with a level of contamination of up to 1.46 108 copies/g. Sequences of viral strains isolated from positive livers belonged to genotype 3 and subtypes 3c, 3e, 3f and 3j. Our results confirmed that raw pork liver food products are a source of risk for humans but they also showed that there is a limited risk of human infection by HEV through the consumption of ham muscle.

      PubDate: 2017-11-11T21:51:08Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.013
      Issue No: Vol. 264 (2017)
       
  • Anti-aflatoxigenic effect of organic acids produced by Lactobacillus
           plantarum
    • Authors: Ana Guimarães; Ana Santiago; José A. Teixeira; Armando Venâncio; Luís Abrunhosa
      Pages: 31 - 38
      Abstract: Publication date: 2 January 2018
      Source:International Journal of Food Microbiology, Volume 264
      Author(s): Ana Guimarães, Ana Santiago, José A. Teixeira, Armando Venâncio, Luís Abrunhosa
      Lactic acid bacteria (LAB), which are commonly used in the production of fermented foods, have been gaining attention for their antifungal and antimycotoxin properties. In this work, the strain Lactobacillus plantarum UM55 was selected among other LAB for inhibiting the growth of Aspergillus flavus. Further, it is shown that cell-free supernatant (CFS) of this strain inhibits the production of aflatoxins (AFLs) by 91%. This inhibition was dependent on CFS pH, increased with increasing concentrations of CFS, and was independent of fungal growth, which was inhibited only by 32%. CFS was also effective in inhibiting the growth and AFLs production in A. parasiticus, A. arachidicola, A. nomius and A. minisclerotigenes. Further, L. plantarum UM55 CFS was analysed for the presence of organic acids and the main differences compared to controls were found in the levels of lactic acid, phenyllactic acid (PLA), hydroxyphenyllactic acid (OH-PLA), and indole lactic acid (ILA). These compounds were individually tested against A. flavus, with all of the compounds showing an inhibiting effect on fungal growth and AFLs production. PLA showed the stronger effects, and the obtained IC90 for the inhibition of growth and AFLs was of 11.9 and 0.87mg/mL, respectively. AFLs IC90 for ILA, OH-PLA and lactic acid were of 1.47, 1.80, and 3.92mg/mL, respectively. The antiaflatoxigenic properties of LAB depend on strain's capability to produce lactic acid, PLA, OH-PLA and ILA.

      PubDate: 2017-11-11T21:51:08Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.025
      Issue No: Vol. 264 (2017)
       
  • Application of whole genome sequence data in analyzing the molecular
           epidemiology of Shiga toxin-producing Escherichia coli O157:H7/H-
    • Authors: Eiji Yokoyama; Shinichiro Hirai; Taichiro Ishige; Satoshi Murakami
      Pages: 39 - 45
      Abstract: Publication date: 2 January 2018
      Source:International Journal of Food Microbiology, Volume 264
      Author(s): Eiji Yokoyama, Shinichiro Hirai, Taichiro Ishige, Satoshi Murakami
      Seventeen clusters of Shiga toxin-producing Escherichia coli O157:H7/- (O157) strains, determined by cluster analysis of pulsed-field gel electrophoresis patterns, were analyzed using whole genome sequence (WGS) data to investigate this pathogen's molecular epidemiology. The 17 clusters included 136 strains containing strains from nine outbreaks, with each outbreak caused by a single source contaminated with the organism, as shown by epidemiological contact surveys. WGS data of these strains were used to identify single nucleotide polymorphisms (SNPs) by two methods: short read data were directly mapped to a reference genome (mapping derived SNPs) and common SNPs between the mapping derived SNPs and SNPs in assembled data of short read data (common SNPs). Among both SNPs, those that were detected in genes with a gap were excluded to remove ambiguous SNPs from further analysis. The effectiveness of both SNPs was investigated among all the concatenated SNPs that were detected (whole SNP set); SNPs were divided into three categories based on the genes in which they were located (i.e., backbone SNP set, O-island SNP set, and mobile element SNP set); and SNPs in non-coding regions (intergenic region SNP set). When SNPs from strains isolated from the nine single source derived outbreaks were analyzed using an unweighted pair group method with arithmetic mean tree (UPGMA) and a minimum spanning tree (MST), the maximum pair-wise distances of the backbone SNP set of the mapping derived SNPs were significantly smaller than those of the whole and intergenic region SNP set on both UPGMAs and MSTs. This significant difference was also observed when the backbone SNP set of the common SNPs were examined (Steel-Dwass test, P≤0.01). When the maximum pair-wise distances were compared between the mapping derived and common SNPs, significant differences were observed in those of the whole, mobile element, and intergenic region SNP set (Wilcoxon signed rank test, P≤0.01). When all the strains included in one complex on an MST or one cluster on a UPGMA were designated as the same genotype, the values of the Hunter-Gaston Discriminatory Power Index for the backbone SNP set of the mapping derived and common SNPs were higher than those of other SNP sets. In contrast, the mobile element SNP set could not robustly subdivide lineage I strains of tested O157 strains using both the mapping derived and common SNPs. These results suggested that the backbone SNP set were the most effective for analysis of WGS data for O157 in enabling an appropriation of its molecular epidemiology.

      PubDate: 2017-11-11T21:51:08Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.019
      Issue No: Vol. 264 (2017)
       
  • Application of Reverse Transcriptase-PCR-DGGE as a rapid method for
           routine determination of Vibrio spp. in foods
    • Authors: Kanchana Chahorm; Cheunjit Prakitchaiwattana
      Pages: 46 - 52
      Abstract: Publication date: 2 January 2018
      Source:International Journal of Food Microbiology, Volume 264
      Author(s): Kanchana Chahorm, Cheunjit Prakitchaiwattana
      The aim of this research was to evaluate the feasibility of PCR-DGGE and Reverse Transcriptase-PCR-DGGE techniques for rapid detection of Vibrio species in foods. Primers GC567F and 680R were initially evaluated for amplifying DNA and cDNA of ten references Vibrio species by PCR method. The GC-clamp PCR amplicons were separated according to their sequences by the DGGE using 10% (w/v) polyacrylamide gel containing 45–70% urea and formamide denaturants. Two pair of Vibrio species, which could not be differentiated on the gel, was Vibrio fluvialis - Vibrio furnissii and Vibrio parahaemolyticus - Vibrio harveyi. To determine the detection limit, in the community of 10 reference strains containing the same viable population, distinct DNA bands of 3 species; Vibrio cholerae, Vibrio mimicus and Vibrio alginolyticus were consistently observed by PCR-DGGE technique. In fact, 5 species; Vibrio cholerae, Vibrio mimicus, Vibrio alginolyticus, Vibrio parahaemolyticus and Vibrio fluvialis consistently observed by Reverse Transcriptase-PCR-DGGE. In the community containing different viable population increasing from 102 to 105 CFU/mL, PCR-DGGE analysis only detected the two most prevalent species, while RT-PCR-DGGE detected the five most prevalent species. Therefore, Reverse Transcriptase-PCR-DGGE was also selected for detection of various Vibrio cell conditions, including viable cell (VC), injured cells from frozen cultures (IVC) and injured cells from frozen cultures with pre-enrichment (PIVC). It was found that cDNA band of all cell conditions gave the same migratory patterns, except that multiple cDNA bands of Plesiomonas shigelloides under IVC and PIVC conditions were found. When Reverse Transcriptase-PCR-DGGE was used for detecting Vibrio parahaemolyticus in the pathogen-spiked food samples, Vibrio parahaemolyticus could be detected in the spiked samples containing at least 102 CFU/g of this pathogen. The results obtained also corresponded to standard method (USFDA, 2004). In comparison with the detection of the Vibrio profiles in fourteen food samples using standard method, Reverse Transcriptase-PCR-DGGE resulted in 100%, 75% and 50% similarity in 3, 1 and 6 food samples, respectively.

      PubDate: 2017-11-11T21:51:08Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.014
      Issue No: Vol. 264 (2017)
       
  • Transcriptomic response of Debaryomyces hansenii during mixed culture in a
           liquid model cheese medium with Yarrowia lipolytica
    • Authors: Reine Malek; Pascal Bonnarme; Françoise Irlinger; Pascale Frey-Klett; Djamila Onésime; Julie Aubert; Valentin Loux; Jean-Marie Beckerich
      Pages: 53 - 62
      Abstract: Publication date: 2 January 2018
      Source:International Journal of Food Microbiology, Volume 264
      Author(s): Reine Malek, Pascal Bonnarme, Françoise Irlinger, Pascale Frey-Klett, Djamila Onésime, Julie Aubert, Valentin Loux, Jean-Marie Beckerich
      Yeasts play a crucial role in cheese ripening. They contribute to the curd deacidification, the establishment of acid-sensitive bacterial communities, and flavour compounds production via proteolysis and catabolism of amino acids (AA). Negative yeast-yeast interaction was observed between the yeast Yarrowia lipolytica 1E07 (YL1E07) and the yeast Debaryomyces hansenii 1L25 (DH1L25) in a model cheese but need elucidation. YL1E07 and DH1L25 were cultivated in mono and co-cultures in a liquid synthetic medium (SM) mimicking the cheese environment and the growth inhibition of DH1L25 in the presence of YL1E07 was reproduced. We carried out microbiological, biochemical (lactose, lactate, AA consumption and ammonia production) and transcriptomic analyses by microarray technology to highlight the interaction mechanisms. We showed that the DH1L25 growth inhibition in the presence of YL1E07 was neither due to the ammonia production nor to the nutritional competition for the medium carbon sources between the two yeasts. The transcriptomic study was the key toward the comprehension of yeast-yeast interaction, and revealed that the inhibition of DH1L25 in co-culture is due to a decrease of the mitochondrial respiratory chain functioning.

      PubDate: 2017-11-11T21:51:08Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.026
      Issue No: Vol. 264 (2017)
       
  • Validation of a Salmonella loop-mediated isothermal amplification assay in
           animal food
    • Authors: Kelly J. Domesle; Qianru Yang; Thomas S. Hammack; Beilei Ge
      Pages: 63 - 76
      Abstract: Publication date: 2 January 2018
      Source:International Journal of Food Microbiology, Volume 264
      Author(s): Kelly J. Domesle, Qianru Yang, Thomas S. Hammack, Beilei Ge
      Loop-mediated isothermal amplification (LAMP) has emerged as a promising alternative to PCR for pathogen detection in food testing and clinical diagnostics. This study aimed to validate a Salmonella LAMP method run on both turbidimetry (LAMP I) and fluorescence (LAMP II) platforms in representative animal food commodities. The U.S. Food and Drug Administration (FDA)'s culture-based Bacteriological Analytical Manual (BAM) method was used as the reference method and a real-time quantitative PCR (qPCR) assay was also performed. The method comparison study followed the FDA's microbiological methods validation guidelines, which align well with those from the AOAC International and ISO. Both LAMP assays were 100% specific among 300 strains (247 Salmonella of 185 serovars and 53 non-Salmonella) tested. The detection limits ranged from 1.3 to 28 cells for six Salmonella strains of various serovars. Six commodities consisting of four animal feed items (cattle feed, chicken feed, horse feed, and swine feed) and two pet food items (dry cat food and dry dog food) all yielded satisfactory results. Compared to the BAM method, the relative levels of detection (RLODs) for LAMP I ranged from 0.317 to 1 with a combined value of 0.610, while those for LAMP II ranged from 0.394 to 1.152 with a combined value of 0.783, which all fell within the acceptability limit (2.5) for an unpaired study. This also suggests that LAMP was more sensitive than the BAM method at detecting low-level Salmonella contamination in animal food and results were available 3days sooner. The performance of LAMP on both platforms was comparable to that of qPCR but notably faster, particularly LAMP II. Given the importance of Salmonella in animal food safety, the LAMP assays validated in this study holds great promise as a rapid, reliable, and robust method for routine screening of Salmonella in these commodities.

      PubDate: 2017-11-11T21:51:08Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.020
      Issue No: Vol. 264 (2017)
       
  • Checking the detail in retail: Occurrence of Cryptosporidium and Giardia
           on vegetables sold across different counters in Chandigarh, India
    • Authors: Kjersti Selstad Utaaker; Anil Kumar; Himanshu Joshi; Suman Chaudhary; Lucy J. Robertson
      Abstract: Publication date: 18 December 2017
      Source:International Journal of Food Microbiology, Volume 263
      Author(s): Kjersti Selstad Utaaker, Anil Kumar, Himanshu Joshi, Suman Chaudhary, Lucy J. Robertson
      Fresh produce has been recognized as a vehicle of infection for protozoan parasites, particularly Cryptosporidium, and, to a lesser extent, Giardia. For both parasites, outbreaks associated with fresh produce have been documented. Although documented outbreaks tend to be from industrialized countries, contamination of fresh produce with these parasites is a global issue. In developing countries, infections with these parasites are often endemic in the community, and basic infrastructure and hygiene measures may be inadequate, thus the likelihood of contamination of fresh produce with these parasites may be higher. Realization of the importance of this transmission route comes against a backdrop of raw salads and more Western culinary habits gaining a foothold, and fresh produce being encouraged as part of the diet due to their associated health benefits. However, if consumption of uncooked fresh produce is going to increase its market sector in India, it is important that it is safe. In this study, various types of fresh produce obtained from three types of vendors in Chandigarh, a major city in Northern India, were analyzed for contamination with Cryptosporidium oocysts and Giardia cysts using a method that has been previously validated in inter-laboratory spiking experiments. A total of 284 samples of different fresh produce items were analyzed, obtained from the different retailers situated in different societal layers of the city. The overall prevalence of contamination of fresh produce with these parasites was just under 11%, with 6% of the vegetables contaminated with Cryptosporidium oocysts, and 5% with Giardia cysts. Contaminated vegetables included turnip, cabbage, carrot, chili, coriander, cucumber, radishes, and tomatoes. Molecular analyses identified contamination with Cryptosporidium parvum and Giardia duodenalis of Assemblage A and Assemblage D, indicating that contamination from animals may be of relevance. Although the prevalence of contamination is similar to those reported in previous studies, the levels of contamination on some items of fresh produce were relatively high. Although the different socioeconomic areas of Chandigarh from which the samples were obtained was not associated with likelihood of contamination, fresh produce from supermarkets had heavier contamination with Cryptosporidium oocysts than fresh produce purchased through other sales outlets. The results are discussed in relation to the fresh produce chain and sales models in Chandigarh, both in terms of where contamination may occur and the potential importance of fresh produce as a transmission vehicle.

      PubDate: 2017-10-08T06:18:06Z
      DOI: 10.1016/j.ijfoodmicro.2017.09.020
      Issue No: Vol. 263 (2017)
       
  • Antimicrobial edible coatings and films from micro-emulsions and their
           food applications
    • Authors: Mingming Guo; Madhav P. Yadav; Tony Z. Jin
      Pages: 9 - 16
      Abstract: Publication date: 18 December 2017
      Source:International Journal of Food Microbiology, Volume 263
      Author(s): Mingming Guo, Madhav P. Yadav, Tony Z. Jin
      This study focused on the use of antimicrobial edible coatings and films from micro-emulsions to reduce populations of foodborne pathogens in foods. Corn-Bio-fiber gum (C-BFG) was used as an emulsifier with chitosan. Allyl isothiocyanate (AIT) and lauric arginate ester (LAE) served as antimicrobials. Micro-emulsions were obtained from a solution consisting of 1% chitosan, 0.5% C-BFG, and 1–4% AIT or LAE which was subject to high pressure homogenization (HPH) processing at 138MPa for 3cycles. Coatings and films produced from the micro-emulsions had micro-pores with sizes ranging from 100 to 300nm and micro-channels that hold antimicrobials effectively and facilitate the release of antimicrobials from the center to the surface of the films or coatings, thus enhancing their antimicrobial efficacy. The coatings and films with 1% AIT reduced populations of Listeria innocua by over 5, 2, and 3 log CFU in culture medium (Tryptic soy broth, TSB), ready-to-eat meat, and strawberries, respectively. The coatings and films with 1% LAE reduced populations of Escherichia coli O157:H7 and Salmonella spp. by over 5 and 2 log CFU in TSB and strawberries, respectively. This study provides an innovative approach for the development of effective antimicrobial materials to reduce food borne pathogenic contaminants on ready-to-eat meat, strawberries, or other food.

      PubDate: 2017-10-14T06:24:12Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.002
      Issue No: Vol. 263 (2017)
       
  • Salmonella survival during thermal dehydration of fresh garlic and storage
           of dehydrated garlic products
    • Authors: Hongmei Zhang; Yan Qi; Lei Wang; Shaokang Zhang; Xiangyu Deng
      Pages: 26 - 31
      Abstract: Publication date: 18 December 2017
      Source:International Journal of Food Microbiology, Volume 263
      Author(s): Hongmei Zhang, Yan Qi, Lei Wang, Shaokang Zhang, Xiangyu Deng
      Salmonella survival was characterized and modeled during thermal dehydration of fresh garlic and storage of dehydrated garlic products. In our experiments that simulated commercial dehydration processing at 80±5°C, moderate level of Salmonella contamination (4–5logCFU/g) on fresh garlic was reduced below the enumeration limit (1.7logCFU/g) after 4.5h of dehydration and not detectable by culture enrichment after 7h. With high level of contamination (7–8logCFU/g), the Salmonella population persisted at 3.6logCFU/g after 8h of processing. By increasing the dehydration temperature to 90±5°C, the moderate and high levels of initial Salmonella load on fresh garlic dropped below the enumeration limit after 1.5 and 3.75h of processing and became undetectable by culture enrichment after 2.5 and 6h, respectively. During the storage of dried garlic products, Salmonella was not able to grow under all tested combinations of temperature (25 and 35°C) and water activity (0.56–0.98) levels, suggesting active inhibition. Storage temperature played a primary role in determining Salmonella survival on dehydrated garlic flakes. Under a typical storage condition at 25°C and ambient relative humidity, Salmonella could persist over months with the population gradually declining (4.3 log reduction over 88days). Granular size of dehydrated garlic had an impact on Salmonella survival, with better survival of the pathogen observed in smaller granules. At the early stage of dehydrated garlic storage (until 7days), rising water activity appeared to initially promote but then inhibited Salmonella survival, resulting in a water activity threshold at 0.73 where Salmonella displayed strongest persistence. However, this phenomenon was less apparent during extended storage (after 14days).

      PubDate: 2017-10-14T06:24:12Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.010
      Issue No: Vol. 263 (2017)
       
  • Virulence genotypes and antimicrobial susceptibility patterns of
           Arcobacter butzleri isolated from seafood and its environment
    • Authors: Srinu Rathlavath; Vandita Kohli; Asem Sanjit Singh; Manjusha Lekshmi; Gayatri Tripathi; Sanath Kumar; Binaya Bhusan Nayak
      Pages: 32 - 37
      Abstract: Publication date: 18 December 2017
      Source:International Journal of Food Microbiology, Volume 263
      Author(s): Srinu Rathlavath, Vandita Kohli, Asem Sanjit Singh, Manjusha Lekshmi, Gayatri Tripathi, Sanath Kumar, Binaya Bhusan Nayak
      Arcobacter butzleri is an emerging pathogen isolated from animals, food and the environment. In this study, 147 A. butzleri isolated from seafood and the coastal environment were tested for the presence of ten putative virulence genes (cadF, cj1349, ciaB, mviN, pldA, tlyA, hecA, hecB, irgA, iroE) and antimicrobial susceptibilities. Majority of the isolates harbored mviN (100%), cj1349 (97.2%), ciaB (95.9%), tlyA (91.8%), pldA (91.1%) and cadF (89.7%). Lower detection rates were observed for hecA (10.8%), hecB (19%), iroE (12.9%) and irgA (17.6%). Three A. butzleri isolates harbored all ten virulence genes. The occurrence of cj1349, ciaB, pldA, tlyA and hecA genes was significantly different (P ≤0.05) among the isolates from different sources. All (100%) A. butzleri isolates were resistant to vancomycin, cephalothin, cefoxitin and sulphamethizole and susceptible to polymyxin-B, kanamycin, streptomycin, gentamicin, tetracycline and imipenem. Resistance to clinically important antibiotics such as cefotaxime (99.3%), ceftazidime (87.7%), nalidixic acid (70.7%), ampicillin (72.1%), ertapenem and amoxicillin-clavulanic acid (41.9%) was observed in A. butzleri from the environment. The isolates were highly susceptible to norfloxacin (97.9%) and colistin (97.2%), followed by ciprofloxacin (88.4%), meropenem (74.8%), chloramphenicol (72.7%) and erythromycin (69.3%). A. butzleri from different sources were not significantly different with respect to their antimicrobial susceptibility patterns. Multidrug resistance was observed in 66 (81.4%) isolates from fish, 29 (72.5%) isolates from shellfish and 17 (65.3%) isolates from coastal water. A. butzleri harboring virulence genes and resistance to multiple antibiotics found in seafood could be a potential health risk to seafood handlers and consumers. Continuous monitoring of seafood for potentially pathogenic A. butzleri is important to understand the evolution of antibiotic resistance in this emerging food pathogen and to determine the antimicrobial therapy regimen in the event of food-borne A. butzleri infections.

      PubDate: 2017-10-14T06:24:12Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.005
      Issue No: Vol. 263 (2017)
       
  • Occurrence of transferable antibiotic resistances in commercialized
           ready-to-eat mealworms (Tenebrio molitor L.)
    • Authors: Andrea Osimani; Federica Cardinali; Lucia Aquilanti; Cristiana Garofalo; Andrea Roncolini; Vesna Milanović; Marina Pasquini; Stefano Tavoletti; Francesca Clementi
      Pages: 38 - 46
      Abstract: Publication date: 18 December 2017
      Source:International Journal of Food Microbiology, Volume 263
      Author(s): Andrea Osimani, Federica Cardinali, Lucia Aquilanti, Cristiana Garofalo, Andrea Roncolini, Vesna Milanović, Marina Pasquini, Stefano Tavoletti, Francesca Clementi
      The present study aimed to assess the occurrence of transferable determinants conferring resistance to tetracyclines, macrolide-lincosamide-streptogramin B, vancomycin, beta-lactams, and aminoglycosides in 40 samples of commercialized edible mealworms (Tenebrio molitor L.) purchased from European Union (EU) and non-EU producers. A high prevalence of tet(K) was observed in all of the samples assayed, with percentages of PCR-based positivity that ranged from 80% (samples from Thailand) to 100% (samples from the Netherlands, Belgium and France). For macrolides, erm(B) prevailed, being detected in 57.5% of the samples assayed, whereas erm(A) and erm(C) were detected with lower frequencies. Genes for resistance to vancomycin were only detected in samples produced in France and Belgium, with 90% and 10% of the samples being positive for vanA, respectively. Beta-lactamase genes were found with low occurrence, whereas the gene aac-aph, conferring high resistance to aminoglycosides, was found in 40% of the samples produced in the Netherlands and Belgium and 20% of the samples produced in Thailand. The results of Principal Coordinate Analysis and Principal Component Analysis depicted a clean separation of the samples collected from the four producers based on the distribution of the 12 AR determinants considered. Given the growing interest on the use of mealworms as a novel protein source, AR detection frequencies found in the present study suggest further investigation into the use of antibiotics during rearing of this insect species and more extensive studies focused on the factors that can affect the diffusion of transferable ARs in the production chain. Until such studies are completed, prudent use of antibiotics during rearing of edible insects is recommended.

      PubDate: 2017-10-14T06:24:12Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.009
      Issue No: Vol. 263 (2017)
       
  • Evaluation of the Gauss-Eyring model to predict thermal inactivation of
           micro-organisms at short holding times
    • Authors: R.A.H. Timmermans; H.C. Mastwijk; M.N. Nierop Groot; M.A.J.S. Van Boekel
      Pages: 47 - 60
      Abstract: Publication date: 18 December 2017
      Source:International Journal of Food Microbiology, Volume 263
      Author(s): R.A.H. Timmermans, H.C. Mastwijk, M.N. Nierop Groot, M.A.J.S. Van Boekel
      Application of mild (non)-thermal processing technologies have received considerable interest as alternative to thermal pasteurisation, because of its shorter holding time and lower temperature aiming for an improved product quality. To understand and develop these alternative technologies, like pulsed electric fields, a proper comparison between the conventional thermal and alternative process is necessary. Up to recent, no suitable models were available to predict the inactivation of micro-organisms by a thermal process at a chosen short holding time, due to non-linearity. The recently developed Gauss-Eyring model with two variables temperature and time has the properties to be a suitable model to apply for short holding times, and was tested for this purpose. Therefore, this study aims to validate if the Gauss-Eyring model can be used to describe non-linear isothermal (a fixed temperature with varying holding time) and isotime (a fixed holding time with varying temperature) thermal inactivation data, and if it is a suitable model to predict the thermal inactivation as a function of temperature for short holding times. Inactivation data of Escherichia coli, Listeria monocytogenes, Lactobacillus plantarum, Salmonella Senftenberg and Saccharomyces cerevisiae in orange juice were collected via isothermal and isotime inactivation kinetics. Survival of the tested micro-organisms was modelled with the Gauss-Eyring model, which contains three parameters σ, Tr and Z. The transition of ‘no inactivation’ to ‘inactivation’ (i.e. the ‘shoulder’ in inactivation curves) can be characterised as the temperature-time (T,t) combination where T = Tr − Z · log 10 (t), with Tr as the reference temperature defined for 1s treatment, Z as the temperature needed for a 10-fold increase of decrease of the holding time t, and σ as the temperature width of the distribution. The Gauss-Eyring model fitted well to the experimental data, and revealed different sensitivity for the tested micro-organisms. Based on the parameter estimations, survival curves for the desired short holding times were predicted.

      PubDate: 2017-10-14T06:24:12Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.001
      Issue No: Vol. 263 (2017)
       
  • Effects of processing parameters on the inactivation of Bacillus cereus
           spores on red pepper (Capsicum annum L.) flakes by microwave-combined cold
           plasma treatment
    • Authors: Jung Eun Kim; Hyeon-Son Choi; Dong-Un Lee; Sea C. Min
      Pages: 61 - 66
      Abstract: Publication date: 18 December 2017
      Source:International Journal of Food Microbiology, Volume 263
      Author(s): Jung Eun Kim, Hyeon-Son Choi, Dong-Un Lee, Sea C. Min
      The efficacy of microwave-combined cold plasma treatment (MCPT) for inactivating Bacillus cereus spores contaminating red pepper (Capsicum annum L.) flakes was investigated. The effects of red pepper drying method, particle size, and water activity (aw) were also evaluated at two levels of microwave power (1700 and 2500W/cm2). The inactivation effect of MCPT was higher at higher microwave power. Spore reduction was more effective with vacuum-dried red pepper than far-infrared-dried flakes. A significantly higher level of spore reduction was observed with the red pepper sample with a smaller surface to volume ratio when one surface (exterior surface) was inoculated (p <0.05). Spore reduction by MCPT at high microwave power increased from 1.7 to 2.6logspores/cm2 when the aw of flake increased from 0.4 to 0.9 (p <0.05). MCPT did not change the color of red pepper flakes. MCPT demonstrated potential as a microbial decontaminating technology for red pepper flakes.

      PubDate: 2017-10-14T06:24:12Z
      DOI: 10.1016/j.ijfoodmicro.2017.09.014
      Issue No: Vol. 263 (2017)
       
  • Effects of the predominant bacteria from meju and doenjang on the
           production of volatile compounds during soybean fermentation
    • Authors: Do-Won Jeong; Sojeong Heo; Bitnara Lee; Hyundong Lee; Keuncheol Jeong; Jae-Young Her; Kwang-Geun Lee; Jong-Hoon Lee
      Pages: 8 - 13
      Abstract: Publication date: Available online 19 September 2017
      Source:International Journal of Food Microbiology
      Author(s): Do-Won Jeong, Sojeong Heo, Bitnara Lee, Hyundong Lee, Keuncheol Jeong, Jae-Young Her, Kwang-Geun Lee, Jong-Hoon Lee
      We inoculated five starter candidates, Enterococcus faecium, Tetragenococcus halophilus, Bacillus licheniformis, Staphylococcus saprophyticus, and Staphylococcus succinus, into sterilized soybeans to predict their effectiveness for flavor production in fermented soybean foods. All of the starter candidates exhibited sufficient growth and acid production on soybean cultures. Twenty-two volatile compounds, such as acids, alcohols, carbonyls, esters, furans, and pyrazines, were detected from the control and starter candidate-inoculated soybean cultures. Principal component analysis of these volatile compounds concluded that E. faecium and T. halophilus produced a similar profile of volatile compounds to soybeans with no dramatic differences in soybean flavor. B. licheniformis and S. succinus produced the crucial volatile compounds that distinguish the flavor profiles of soybean. During soybean fermentation, phenylmethanol and 2,3,5,6-tetramethylpyrazine were determined as odor notes specific to B. licheniformis and 3-methylbutyl acetate as an odor note specific to S. succinus.

      PubDate: 2017-09-24T02:18:52Z
      DOI: 10.1016/j.ijfoodmicro.2017.09.011
      Issue No: Vol. 262 (2017)
       
  • Biotransformation of soy whey into soy alcoholic beverage by four
           commercial strains of Saccharomyces cerevisiae
    • Authors: Jian-Yong Chua; Yuyun Lu; Shao-Quan Liu
      Pages: 14 - 22
      Abstract: Publication date: 4 December 2017
      Source:International Journal of Food Microbiology, Volume 262
      Author(s): Jian-Yong Chua, Yuyun Lu, Shao-Quan Liu
      Soy whey is a liquid waste stream generated from tofu and soy protein manufacturing, and is commonly disposed of into the drainage system in food industry. Instead of disposing of soy whey as a waste, it could be used to produce alcoholic beverages. This study investigated the feasibility of converting soy whey into soy alcoholic beverage using four commercial Saccharomyces cerevisiae strains as a zero-waste approach to tackle the soy whey disposal issue. The four Saccharomyces yeasts grew by approximately 2logCFU/mL and produced approximately 7–8% (v/v) of ethanol. Isoflavone glucosides were hydrolyzed and transformed into isoflavone aglycones, increasing the antioxidant capacity. New aroma-active volatiles, especially esters and higher alcohols, were produced and imparted fruity and floral notes to the soy alcoholic beverage. Therefore, alcoholic fermentation would serve as a solution toward zero-waste manufacturing by biotransforming soy whey into a world's first novel functional alcoholic beverage naturally enriched with free isoflavones.

      PubDate: 2017-09-30T19:37:08Z
      DOI: 10.1016/j.ijfoodmicro.2017.09.007
      Issue No: Vol. 262 (2017)
       
  • Emergence of Salmonella enterica serovar Indiana and California isolates
           with concurrent resistance to cefotaxime, amikacin and ciprofloxacin from
           chickens in China
    • Authors: Yongxiang Wang; Anyun Zhang; Yongqiang Yang; Changwei Lei; Wei Jiang; Bihui Liu; Hongping Shi; Linghan Kong; Guangyang Cheng; Xiuzhong Zhang; Xin Yang; Hongning Wang
      Pages: 23 - 30
      Abstract: Publication date: 4 December 2017
      Source:International Journal of Food Microbiology, Volume 262
      Author(s): Yongxiang Wang, Anyun Zhang, Yongqiang Yang, Changwei Lei, Wei Jiang, Bihui Liu, Hongping Shi, Linghan Kong, Guangyang Cheng, Xiuzhong Zhang, Xin Yang, Hongning Wang
      The aim of this study was to investigate the prevalence and characterization of Salmonella concerning the poultry industry in China. A total of 170 non-duplicate Salmonella isolates were recovered from the 1540 chicken samples. Among the Salmonella isolates from chickens, the predominant serovars were S. enterica serovar Enteritidis (S. Enteritidis) (49/170, 28.8%), S. enterica serovar Indiana (S. Indiana) (37/170, 21.8%) and S. enterica serovar California (S. California) (34/170, 20.0%). High antimicrobial resistance was observed for ciprofloxacin (68.2%), amikacin (48.2%) and cefotaxime (44.7%). Of particular concerns were the 18 S. Indiana and 17 S. California isolates, which were concurrently resistant to cefotaxime, amikacin and ciprofloxacin. The bla CTX-M genes, 16S rRNA methylase genes (armA, rmtD or rmtC) and five plasmid-mediated quinolone resistance (PMQR) determinants (aac(6′)-Ib-cr, oqxAB, qnrB, qepA and qnrD) were identified in 18 S. Indiana and 17 S. California isolates. To clarify their genetic correlation, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were further conducted. PFGE profiles showed that the majority of S. Indiana and S. California isolates were clonally unrelated with a standard cut-off of 85%. The results of MLST demonstrated that ST17 and ST40 were the most common ST types in S. Indiana and S. California isolates, respectively. Our findings indicated that the multiple antibiotic resistant S. Indiana and S. California isolates were widespread in chicken in China and might pose a potential threat to public health.

      PubDate: 2017-10-14T06:24:12Z
      DOI: 10.1016/j.ijfoodmicro.2017.09.012
      Issue No: Vol. 262 (2017)
       
  • Food poisoning outbreak in Tokyo, Japan caused by Staphylococcus argenteus
    • Authors: Yasunori Suzuki; Hiroaki Kubota; Hisaya K. Ono; Makiko Kobayashi; Konomi Murauchi; Rei Kato; Akihiko Hirai; Kenji Sadamasu
      Pages: 31 - 37
      Abstract: Publication date: 4 December 2017
      Source:International Journal of Food Microbiology, Volume 262
      Author(s): Yasunori Suzuki, Hiroaki Kubota, Hisaya K. Ono, Makiko Kobayashi, Konomi Murauchi, Rei Kato, Akihiko Hirai, Kenji Sadamasu
      Staphylococcus argenteus is a novel species subdivided from Staphylococcus aureus. Whether this species can cause food poisoning outbreaks is unknown. This study aimed to investigate the enterotoxigenic activities of two food poisoning isolates suspected to be S. argenteus (Tokyo13064 and Tokyo13069). The results for phylogenic trees, constructed via whole genome sequencing, demonstrated that both isolates were more similar to a type strain of S. argenteus (MSHR1132) than any S. aureus strain. Moreover, the representative characteristics of S. argenteus were present in both strains, namely both isolates belong to the CC75 lineage and both lack a crtOPQMN operon. Thus, both were determined to be “S. argenteus.” The compositions of the two isolates' accessory elements differed from those of MSHR1132. For example, the seb-related Staphylococcus aureus pathogenicity island, SaPIishikawa11, was detected in Tokyo13064 and Tokyo13069 but not in MSHR1132. Both isolates were suggested to belong to distinct lineages that branched off from MSHR1132 lineages in terms of accessory elements. Tokyo13064 and Tokyo13069 expressed high levels of s(arg)eb and produced S(arg)EB protein, indicating that both have the ability to cause food poisoning. Our findings suggest that S. argenteus harboring particular accessory elements can cause staphylococcal diseases such as food poisoning, similarly to S. aureus.

      PubDate: 2017-10-14T06:24:12Z
      DOI: 10.1016/j.ijfoodmicro.2017.09.005
      Issue No: Vol. 262 (2017)
       
  • Inside Front Cover - Editorial Board
    • Abstract: Publication date: 16 January 2018
      Source:International Journal of Food Microbiology, Volume 265


      PubDate: 2017-11-11T21:51:08Z
       
  • Prevalence of curli genes among Cronobacter species and their roles in
           biofilm formation and cell-cell aggregation
    • Authors: Lan
      Abstract: Publication date: 16 January 2018
      Source:International Journal of Food Microbiology, Volume 265
      Author(s): Lan Hu
      Cronobacter species are food-borne opportunistic pathogens that cause sepsis, meningitis, and necrotizing enterocolitis in neonates. Bacterial pathogens such as pathogenic Escherichia coli and Salmonella species express extracellular curli fimbriae that are involved in rugosity, biofilm formation, and host cell adherence. csgBAC operon encodes the major curli structural subunit CsgA and the nucleator protein CsgB. csgDEFG operon encodes the regulatory protein CsgD and putative assembly factors. In this study, the curli operons were analyzed in the sequences of 13 Cronobacter strains and other enteric bacterial pathogens. Isogenic mutants of csgA and csgB were generated in C. turicensis LMG23827 (z3032). csgA and csgB mutants did not express curli fimbriae as indicated by a lack of Congo red binding and absence of curli by electron microscopic evaluation. Compared to the wild type strain, biofilm formation and cell-cell aggregation of csgA and csgB mutants were remarkably decreased. The prevalence of curli operons were investigated in 231 Cronobacter strains isolated from different sources using polymerase chain reaction (PCR) assay. The results of the PCR analysis showed that csgA and csgG were present in 30% clinical isolates, 8% food, and 11% environmental isolates. These genes were present in C. dublinensis, C. malonaticus, C. turicensis, and C. universalis, but not in C. muytjensii and C. sakazakii. Our data indicate that csgBAC and csgDEFG operons were present about three fold higher in clinical isolates than in isolates from other sources. The csgA and csgB genes were shown to be involved in the early stages of biofilm development and cell-cell aggregation in Cronobacter.

      PubDate: 2017-11-11T21:51:08Z
       
  • ICFMH Announcment
    • Abstract: Publication date: 16 January 2018
      Source:International Journal of Food Microbiology, Volume 265


      PubDate: 2017-11-11T21:51:08Z
       
  • Inside Front Cover - Editorial Board
    • Abstract: Publication date: 2 January 2018
      Source:International Journal of Food Microbiology, Volume 264


      PubDate: 2017-11-11T21:51:08Z
       
  • ICFMH Announcment
    • Abstract: Publication date: 2 January 2018
      Source:International Journal of Food Microbiology, Volume 264


      PubDate: 2017-11-11T21:51:08Z
       
  • Antimicrobial activities of gaseous essential oils against Listeria
           monocytogenes on a laboratory medium and radish sprouts
    • Authors: Gyeongmin Lee; Yoonbin Kim; Hoikyung Kim; Larry R. Beuchat; Jee-Hoon Ryu
      Abstract: Publication date: Available online 4 November 2017
      Source:International Journal of Food Microbiology
      Author(s): Gyeongmin Lee, Yoonbin Kim, Hoikyung Kim, Larry R. Beuchat, Jee-Hoon Ryu
      The aim of this study was to evaluate the antimicrobial activities of gaseous essential oils (EO gases) against Listeria monocytogenes on the surfaces of a laboratory medium and radish sprouts. We determined the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) values of EO gases from eight EOs extracted from basil leaves, carrot seed, cinnamon bark, cinnamon leaves, clove flower buds, oregano leaves, thyme flowers (linalool), and thyme leaves (thymol) against L. monocytogenes on a nutrient agar supplemented with 1% glucose and 0.025% bromocresol purple (NGBA). Oregano, thyme thymol, and cinnamon bark EO gases showed the strongest antilisterial activities (MIC and MLC, 78.1μL/L). We also investigated the inhibitory and lethal activities of these gases against L. monocytogenes on the surface of radish sprouts. The number of L. monocytogenes after exposure to EO gases at ≥156μL/L was significantly (P ≤0.05) lower than that of untreated L. monocytogenes. For example, the initial number of L. monocytogenes on the surface of radish sprouts (ca. 6.3logCFU/g) decreased by 1.4logCFU/g within 24h at 30°C and 43% relative humidity (RH) without EO gas treatment, whereas the number of L. monocytogenes after exposure to oregano, thyme thymol, and cinnamon bark EO gases at 156μL/L decreased by 2.1, 2.1, and 1.8logCFU/g, respectively, after 24h. Although EO gases exerted greater lethal activities at higher concentrations (312 and 625μL/L), L. monocytogenes on the surface of radish sprouts was not completely inactivated. The number of L. monocytogenes on sprouts treated with oregano, thyme thymol, and cinnamon bark EO gases at 625μL/L decreased by 2.7–3.0logCFU/g after 24h at 30°C and 43% RH. Results indicate that EO gases that showed antilisterial activities on a laboratory medium also exhibited reduced lethal activity on the surface of radish sprouts. These findings will be useful when developing strategies to inactivate L. monocytogenes and possibly other foodborne pathogens on sprouts and perhaps other foods using EO gases.

      PubDate: 2017-11-05T12:45:39Z
      DOI: 10.1016/j.ijfoodmicro.2017.11.001
       
  • Inside Front Cover - Editorial Board
    • Abstract: Publication date: 18 December 2017
      Source:International Journal of Food Microbiology, Volume 263


      PubDate: 2017-10-28T12:35:05Z
       
  • ICFMH Announcment
    • Abstract: Publication date: 18 December 2017
      Source:International Journal of Food Microbiology, Volume 263


      PubDate: 2017-10-28T12:35:05Z
       
  • Inside Front Cover - Editorial Board
    • Abstract: Publication date: 4 December 2017
      Source:International Journal of Food Microbiology, Volume 262


      PubDate: 2017-10-14T06:24:12Z
       
  • Bacteria, mould and yeast spore inactivation studies by scanning electron
           microscope observations
    • Authors: Siti N.M. Rozali; Elham A. Milani; Rebecca C. Deed; Filipa V.M. Silva
      Abstract: Publication date: Available online 4 October 2017
      Source:International Journal of Food Microbiology
      Author(s): Siti N.M. Rozali, Elham A. Milani, Rebecca C. Deed, Filipa V.M. Silva
      Spores are the most resistant form of microbial cells, thus difficult to inactivate. The pathogenic or food spoilage effects of certain spore-forming microorganisms have been the primary basis of sterilization and pasteurization processes. Thermal sterilization is the most common method to inactivate spores present on medical equipment and foods. High pressure processing (HPP) is an emerging and commercial non-thermal food pasteurization technique. Although previous studies demonstrated the effectiveness of thermal and non-thermal spore inactivation, the in-depth mechanisms of spore inactivation are as yet unclear. Live and dead forms of two food spoilage bacteria, a mould and a yeast were examined using scanning electron microscopy before and after the inactivation treatment. Alicyclobacillus acidoterrestris and Geobacillus stearothermophilus bacteria are indicators of acidic foods pasteurization and sterilization processes, respectively. Neosartorya fischeri is a phyto-pathogenic mould attacking fruits. Saccharomyces cerevisiae is a yeast with various applications for winemaking, brewing, baking and the production of biofuel from crops (e.g. sugar cane). Spores of the four microbial species were thermally inactivated. Spores of S. cerevisiae were observed in the ascus and free form after thermal and HPP treatments. Different forms of damage and cell destruction were observed for each microbial spore. Thermal treatment inactivated bacterial spores of A. acidoterrestris and G. stearothermophilus by attacking the inner core of the spore. The heat first altered the membrane permeability allowing the release of intracellular components. Subsequently, hydration of spores, physicochemical modifications of proteins, flattening and formation of indentations occurred, with subsequent spore death. Regarding N. fischeri, thermal inactivation caused cell destruction and leakage of intracellular components. Both thermal and HPP treatments of S. cerevisiae free spores attacked the inner membrane, altering its permeability, and allowing in final stages the transfer of intracellular components to the outside. The spore destruction caused by thermal treatment was more severe than HPP, as HPP had less effect on the spore core. All injured spores have undergone irreversible volume and shape changes. While some of the leakage of spore contents is visible around the deformed but fully shaped spore, other spores exhibited large indentations and were completely deformed, apparently without any contents inside. This current study contributed to the understanding of spore inactivation by thermal and non-thermal processes.

      PubDate: 2017-10-08T06:18:06Z
      DOI: 10.1016/j.ijfoodmicro.2017.10.008
       
  • New insights into resistance to colistin and third-generation
           cephalosporins of Escherichia coli in poultry, Portugal: Novel
           blaCTX-M-166 and blaESAC genes
    • Authors: Vera Manageiro; Lurdes Clemente Rafael Ivone Correia Teresa Albuquerque Ferreira
      Abstract: Publication date: Available online 4 October 2017
      Source:International Journal of Food Microbiology
      Author(s): Vera Manageiro, Lurdes Clemente, Rafael Graça, Ivone Correia, Teresa Albuquerque, Eugénia Ferreira, Manuela Caniça
      The increasing incidence of intestinal colonization with extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and Gram negative organisms that has been observed in food animals such as poultry, cattle and pigs, are suggestive that animals, food and environment are potential sources of ESBL-producing bacteria. Hence, the aim of this study was to characterized commensal E. coli obtained from healthy broiler and turkey flocks at slaughter for the presence of penicillinases-, ESBL-, extended-spectrum AmpC (ESAC)-, plasmid-mediated quinolone resistance- and MCR-encoding genes. Study of clonal relatedness showed genetic diversity among CTX-M-type, SHV-12 and TEM-52 producing isolates with human isolates of the same type, was also assessed. We detected that eleven (5.4%, 11/202) and forty-five (2.2%, 45/185) E. coli isolates from broilers and turkeys, respectively, carried bla ESBL or bla ESAC genes and two isolates from turkeys carried mcr-1 gene. A new variant bla CTX-M-166 was reported in a multidrug resistant isolate from a broiler flock. Overall, we detected a diversity of resistance mechanisms among E. coli from food-producing animals, all of them with high importance at a public health level.

      PubDate: 2017-10-08T06:18:06Z
       
 
 
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