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  Subjects -> BIOLOGY (Total: 3036 journals)
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MICROBIOLOGY (257 journals)                  1 2 | Last

Showing 1 - 200 of 258 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: 8)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 23)
Advances in Microbiology     Open Access   (Followers: 24)
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 Current Microbiology     Open Access  
American Journal of Infectious Diseases and Microbiology     Open Access   (Followers: 24)
American Journal of Microbiological Research     Open Access   (Followers: 2)
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: 9)
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: 27)
Antiviral Research     Hybrid Journal   (Followers: 8)
Applied and Environmental Microbiology     Hybrid Journal   (Followers: 47)
Applied Biochemistry and Microbiology     Hybrid Journal   (Followers: 16)
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: 12)
Brazilian Journal of Microbiology     Open Access   (Followers: 3)
Canadian Journal of Infectious Diseases and Medical Microbiology     Open Access   (Followers: 5)
Canadian Journal of Microbiology     Hybrid Journal   (Followers: 6)
Cell Biology : Research & Therapy     Hybrid Journal   (Followers: 5)
Cell Host & Microbe     Full-text available via subscription   (Followers: 21)
Cell Medicine     Open Access   (Followers: 5)
Cell Regeneration     Open Access   (Followers: 1)
Cell Stem Cell     Full-text available via subscription   (Followers: 36)
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: 3)
Current Issues in Molecular Biology     Open Access   (Followers: 3)
Current Microbiology     Hybrid Journal   (Followers: 15)
Current Molecular Biology Reports     Hybrid Journal   (Followers: 1)
Current Opinion in Microbiology     Hybrid Journal   (Followers: 33)
Current Regenerative Medicine     Hybrid Journal  
Current Research in Microbiology     Open Access   (Followers: 18)
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: 4)
Environmental Microbiology     Hybrid Journal   (Followers: 21)
Environmental Microbiology Reports     Hybrid Journal   (Followers: 7)
Enzyme and Microbial Technology     Hybrid Journal   (Followers: 13)
Epigenetics of Degenerative Diseases     Open Access   (Followers: 5)
Epigenomes     Open Access  
European Journal of Clinical Microbiology & Infectious Diseases     Hybrid Journal   (Followers: 19)
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: 10)
Fems Microbiology Letters     Hybrid Journal   (Followers: 22)
Fems Microbiology Reviews     Hybrid Journal   (Followers: 27)
Fermentation     Open Access   (Followers: 1)
Folia Histochemica et Cytobiologica     Open Access  
Folia Microbiologica     Hybrid Journal   (Followers: 1)
Food Microbiology     Hybrid Journal   (Followers: 18)
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: 16)
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: 9)
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: 10)
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: 2)
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: 16)
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: 7)
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 Organic and Biomolecular Simulations     Open Access  
Journal of Pharmacy & Bioresources     Full-text available via subscription   (Followers: 3)
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   (Followers: 1)
Medical Mycology     Open Access   (Followers: 4)
Memórias do Instituto Oswaldo Cruz     Open Access  
Metagenomics     Unknown  
Methods in Molecular Biology     Hybrid Journal   (Followers: 19)
Microbes and Health     Open Access   (Followers: 1)
Microbes and Infection     Full-text available via subscription   (Followers: 6)
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: 12)
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: 27)
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: 10)
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)

        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  [3123 journals]
  • Modelling the growth of Listeria monocytogenes in Mediterranean fish
           species from aquaculture production
    • Authors: Araceli Bolívar; Jean Carlos Correia Peres Costa; Guiomar D. Posada-Izquierdo; Antonio Valero; Gonzalo Zurera; Fernando Pérez-Rodríguez
      Pages: 14 - 21
      Abstract: Publication date: 2 April 2018
      Source:International Journal of Food Microbiology, Volume 270
      Author(s): Araceli Bolívar, Jean Carlos Correia Peres Costa, Guiomar D. Posada-Izquierdo, Antonio Valero, Gonzalo Zurera, Fernando Pérez-Rodríguez
      Over the last couple of decades, several studies have evaluated growth dynamics of L. monocytogenes in lightly processed and ready-to-eat (RTE) fishery products mostly consumed in Nordic European countries. Other fish species from aquaculture production are of special interest since their relevant consumption patterns and added value in Mediterranean countries, such as sea bream and sea bass. In the present study, the growth of L. monocytogenes was evaluated in fish-based juice (FBJ) by means of optical density (OD) measurements in a temperature range 2–20 °C under different atmosphere conditions (i.e. reduced oxygen and aerobic). The Baranyi and Roberts model was used to estimate the maximum growth rate (μ max ) from the observed growth curves. The effect of storage temperature on μ max was modelled using the Ratkowsky square root model. The developed models were validated using experimental growth data for L. monocytogenes in sea bream and sea bass fillets stored under static and dynamic temperature conditions. Overall, models developed in FBJ provided fail-safe predictions for L. monocytogenes growth. For the model generated under reduced oxygen conditions, bias and accuracy factor for growth rate predictions were 1.15 and 1.25, respectively, showing good performance to adequately predict L. monocytogenes growth in Mediterranean fish products. The present study provides validated predictive models for L. monocytogenes growth in Mediterranean fish species to be used in microbial risk assessment and shelf-life studies.

      PubDate: 2018-02-15T19:45:16Z
      DOI: 10.1016/j.ijfoodmicro.2018.02.005
      Issue No: Vol. 270 (2018)
       
  • Mycobiota and co-occurrence of mycotoxins in South African maize-based
           opaque beer
    • Authors: Ifeoluwa Adekoya; Adewale Obadina; Cynthia Chilaka Adaku; Marthe De Boevre; Sheila Okoth; Sarah De Saeger; Patrick Njobeh
      Pages: 22 - 30
      Abstract: Publication date: 2 April 2018
      Source:International Journal of Food Microbiology, Volume 270
      Author(s): Ifeoluwa Adekoya, Adewale Obadina, Cynthia Chilaka Adaku, Marthe De Boevre, Sheila Okoth, Sarah De Saeger, Patrick Njobeh
      Beer, a beverage consumed throughout the world, is mainly derived from cereals. In this study, fungal and mycotoxin contamination, as well as the physicochemical properties of maize-based opaque beer (umqombothi) obtained from the Gauteng province of South Africa, was investigated. The mean water activity, pH and total titratable acidity of the analysed beer samples were 0.91, 3.76 and 1.20% lactic acid, respectively. The investigation revealed Aspergillus, Penicillium, Phoma and Saccharomyces as the predominant fungal genera with a mean fungal load of 3.66 × 105 CFU/mL. Among the mycotoxigenic fungal species recovered, Aspergillus flavus had the highest incidence of 26%. Previously unreported strains such as P. chrysogenum strain AD25, A. sydowii strain AD 22 and A. tritici strain AD 11 were found. Furthermore, mycotoxin quantitative analysis via liquid chromatography-tandem mass spectrophotometry showed that deoxynivalenol was the dominant mycotoxin occurring in 84% of the samples. This was followed by enniatin B that occurred in 75% of samples ranging from 12 to 44 μg/L and fumonisin B1 (FB1) (incidence of 53% at a maximum level of 182 μg/L). Generally, there was low occurrence aflatoxins, whereas T-2, HT-2, nivalenol, zearalenone, 3- and 15-acetyl-deoxynivalenol were not detected. All the samples analysed had safe levels of mycotoxins tested but were contaminated by at least two mycotoxins that could pose some additive or synergistic health effects among consumers. On average: a 60 kg adult consuming 1–6 L/day of the beer was exposed to FB1 + FB2 at an estimated 2.20–13.20 μg/kg body weight/day. These values were far above the maximum tolerable daily intake of 2 μg/kg bw/day established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The study demonstrates that consumption of umqombothi can significantly enhance dietary exposure to multiple mycotoxins among consumers, and therefore accentuates the need for strategies aimed at reducing toxigenic fungal colonization and mycotoxin contamination in the beer processing chain.

      PubDate: 2018-02-15T19:45:16Z
      DOI: 10.1016/j.ijfoodmicro.2018.02.001
      Issue No: Vol. 270 (2018)
       
  • Bovine meat versus pork in Toxoplasma gondii transmission in Italy: A
           quantitative risk assessment model
    • Authors: Simone Belluco; Ilaria Patuzzi; Antonia Ricci
      Pages: 1 - 11
      Abstract: Publication date: 23 March 2018
      Source:International Journal of Food Microbiology, Volume 269
      Author(s): Simone Belluco, Ilaria Patuzzi, Antonia Ricci
      Toxoplasma gondii is a widespread zoonotic parasite with a high seroprevalence in the human population and the ability to infect almost all warm blooded animals. Humans can acquire toxoplasmosis from different transmission routes and food plays a critical role. Within the food category, meat is of utmost importance, as it may contain bradyzoites inside tissue cysts, which can potentially cause infection after ingestion if parasites are not inactivated through freezing or cooking before consumption. In Italy, the most commonly consumed meat-producing animal species are bovines and pigs. However, T. gondii prevalence and consumption habits for meat of these animal species are very different. There is debate within the scientific community concerning which of these animal species is the main source of meat-derived human toxoplasmosis. The aim of this work was to build a quantitative risk assessment model to estimate the yearly probability of acquiring toxoplasmosis infection due to consumption of bovine meat and pork (excluding cured products) in Italy, taking into account the different eating habits. The model was fitted with data obtained from the literature regarding: bradyzoite concentrations, portion size, dose-response relation, prevalence of T. gondii in bovines and swine, meat consumption and meat preparation habits. Alternative handling scenarios were considered. The model estimated the risk per year of acquiring T. gondii infection in Italy from bovine and swine meat to be 0.034% and 0.019%, respectively. Results suggest that, due to existing eating habits, bovine meat can be a not negligible source of toxoplasmosis in Italy.

      PubDate: 2018-01-27T09:09:06Z
      DOI: 10.1016/j.ijfoodmicro.2017.12.026
      Issue No: Vol. 269 (2018)
       
  • Ultrasound improves antimicrobial effect of sodium dichloroisocyanurate to
           reduce Salmonella Typhimurium on purple cabbage
    • Authors: Ana Lúcia Almeida Duarte; Denes Kaic Alves do Rosário; Syllas Borburema Silva Oliveira; Hygor Lendell Silva de Souza; Raquel Vieira de Carvalho; Joel Camilo Souza Carneiro; Pollyanna Ibrahim Silva; Patrícia Campos Bernardes
      Pages: 12 - 18
      Abstract: Publication date: 23 March 2018
      Source:International Journal of Food Microbiology, Volume 269
      Author(s): Ana Lúcia Almeida Duarte, Denes Kaic Alves do Rosário, Syllas Borburema Silva Oliveira, Hygor Lendell Silva de Souza, Raquel Vieira de Carvalho, Joel Camilo Souza Carneiro, Pollyanna Ibrahim Silva, Patrícia Campos Bernardes
      The consumer's interest in ready-to-eat, fast-ready, nutritious and fresh foods is a major challenge for the food industry. Thus, studies on new sanitization methods are relevant. The effect of Sodium Hypochlorite (SH), Benzalkonium Chloride (BC), and Sodium Dichloroisocyanurate (SD) isolated or combined with Ultrasound (US) in purple cabbage quality over 7 days of storage at 8 ± 1 °C was evaluated. The natural microbiota (mesophilic aerobic bacteria, lactic acid bacteria and coliforms), intentionally inoculated Salmonella Typhimurium, physicochemical quality (anthocyanins, pH, total titratable acidity, instrumental color and mass loss) and sensorial quality (multiple comparison test and visual sensory acceptance) were analyzed. The best treatments for natural microbiota reduction were BC and US + BC, which in general reduced between 1.9 and 3.2 log cfu/g. US improved (p < .05) the effect of SD reducing almost 4 log cycles in the population of S. Typhimurium adhered to cabbage. The treatments with benzalkonium chloride resulted in important physicochemical changes in cabbage. The treatments SD and US + SD did not alter the physicochemical and sensorial characteristics of purple cabbage. Therefore, ultrasound combined with sodium dichloroisocyanurate is a promising alternative for the reduction of microbiological contaminants of purple cabbage without physicochemical, sensory and anthocyanin content loss.

      PubDate: 2018-02-04T21:46:22Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.007
      Issue No: Vol. 269 (2018)
       
  • Microbial inactivation and MLF performances of Tempranillo Rioja wines
           treated with PEF after alcoholic fermentation
    • Authors: Lucía González-Arenzana; Isabel López-Alfaro; Teresa Garde-Cerdán; Javier Portu; Rosa López; Pilar Santamaría
      Pages: 19 - 26
      Abstract: Publication date: 23 March 2018
      Source:International Journal of Food Microbiology, Volume 269
      Author(s): Lucía González-Arenzana, Isabel López-Alfaro, Teresa Garde-Cerdán, Javier Portu, Rosa López, Pilar Santamaría
      This study was performed with the aim of reducing the microbial communities of wines after alcoholic fermentation to improve the establishment of commercial Oenococcus oeni inoculum for developing the malolactic fermentation. Microbial community reduction was accomplished by applying Pulsed Electric Field (PEF) technology to four different wines. Overall, significant reductions in yeast population were observed. To a lesser extent, lactic acid bacteria were reduced while acetic acid bacteria were completely eliminated after the PEF treatment. In three out of the four tested wines, a decrease in the competitive pressure between microorganisms due to the detected reduction led to a general but slight shortening of the malolactic fermentation duration. In the wine with the most adverse conditions to commercial starter establishment, the shortest malolactic fermentation was reached after PEF treatment. Finally, the sensorial quality of three out of the four treated wines was considered better after the PEF treatment. Therefore, PEF technology meant an important tool for improving the malolactic fermentation performance.

      PubDate: 2018-01-27T09:09:06Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.008
      Issue No: Vol. 269 (2018)
       
  • Outgraded produce variably retains surface inoculated Escherichia coli
           through washing
    • Authors: Shiyu Cai; Randy W. Worobo; Abigail B. Snyder
      Pages: 27 - 35
      Abstract: Publication date: 23 March 2018
      Source:International Journal of Food Microbiology, Volume 269
      Author(s): Shiyu Cai, Randy W. Worobo, Abigail B. Snyder
      The use of secondary quality produce has gained attention as a solution to food waste in both the U.S. and Europe. The purpose of this study was to evaluate the impact of using secondary quality or outgraded produce on the retention of surface inoculated E. coli following a rinse treatment on four model fresh produce systems (apple, tomato, carrot, lettuce). A three-strain cocktail of rifampicin-resistant generic E. coli, with a concentration of 9.0 log CFU/mL, was spot-inoculated on the intact surfaces of U.S. No.1 grade produce items and damaged or decayed areas of outgraded produce items. Generally, outgraded produce of all four kinds retained higher levels of inoculated E. coli following two postharvest treatments, chlorinated (150 ppm) or water only. However, physical damage, those defects which compromised the integrity of the produce surface, lead to significantly greater E. coli levels following rinsing than did physiological defects. Compared to U.S. No.1 quality apples, outgraded apples retained 4.3 ± 1.4 log CFU/g more E. coli following water only treatment, and 3.6 ± 1.7 log CFU/g more following chlorine treatment. Outgraded tomatoes retained significantly more (3.5 ± 1.1 log CFU/g) inoculated E. coli following water only rinse and 3.0 ± 1.4 log CFU/g more inoculated E. coli following chlorine treatment than U.S. No.1 quality tomatoes did under the same treatment conditions. Outgraded carrots retained 1 ± 1.1 log more CFU/g inoculated E. coli following water only treatment and 0.5 ± 0.8 log more CFU/g inoculated E. coli following chlorine treatment, compared to U.S. No.1 carrots. Outgraded lettuce leaves retained 1.6 ± 0.5 log CFU/g more inoculated E. coli following water only treatment and 4.1 ± 0.4 log CFU/g more inoculated E. coli following chlorine treatment than did U.S. No.1 quality lettuce leaves under the same treatment conditions. Treating with 150 ppm chlorine was not sufficient to eliminate the increased microbial retention associated with secondary quality or outgraded produce, and the efficacy of disinfection was greatly affected by type of defect. Apples with physical damage retained significantly higher E. coli loads than did those with physiological defects, an additional 2.6 log CFU/g under chlorine treatment and 0.8 log CFU/g more under was water only treatment. Tomatoes with physical damage had a 1.3-log CFU/g and 0.6-log CFU/g average increase of retained E. coli counts compared to those with physiological defects following a chlorine and water only treatment, respectively. Although a chlorine dip provided only a modest reduction in pathogens, generally, outgraded produce with physiological defects may present less food safety risks if introduced into the fresh market than does produce with physical damage due to their enhanced retention of bacterial cells. Therefore, as industry considers how to minimize its food waste problem, preferentially directing physically damaged produce away from the fresh market will help to minimize risk while maximizing food resources.

      PubDate: 2018-02-04T21:46:22Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.012
      Issue No: Vol. 269 (2018)
       
  • The impact of dairy cows' bedding material and its microbial content on
           the quality and safety of milk – A cross sectional study of UK farms
    • Authors: Andrew J. Bradley; Katharine A. Leach; Martin J. Green; Jenny Gibbons; Ian C. Ohnstad; David H. Black; Barbara Payne; Victoria E. Prout; James E. Breen
      Pages: 36 - 45
      Abstract: Publication date: 23 March 2018
      Source:International Journal of Food Microbiology, Volume 269
      Author(s): Andrew J. Bradley, Katharine A. Leach, Martin J. Green, Jenny Gibbons, Ian C. Ohnstad, David H. Black, Barbara Payne, Victoria E. Prout, James E. Breen
      The introduction of bedding dairy cows on recycled manure solids (RMS) in the UK led to concern by competent authorities that there could be an increased, unacceptable risk to animal and human health. A cross-sectional study was designed to evaluate the microbial content of different bedding materials, when used by dairy cows, and its impact on the microbial content of milk. Data were collected from farms bedding lactating cows on sand (n=41), sawdust (n=44) and RMS (n=40). The mean duration of RMS use prior to sampling was 13months. Total bacterial count, and counts of Streptococcus/Enterococcus spp., Staphylococcus spp., Bacillus cereus, thermophilic, thermoduric and psychrotrophic bacteria were determined in used bedding and milk. Samples were evaluated for the presence/absence of Listeria monocytogenes, Salmonella spp. and Yersinia enterocolitica. Data on milking practices were collected to investigate their potential to reduce microbial transfer from bedding to milk. There were substantial differences in bacterial counts both within and between bedding materials. However, there were no significant differences between bedding groups in counts in milk for any of the organisms studied, and no significant correlations between bacterial load in used bedding and milk. Fore-milking was associated with a reduced total bacterial count in milk. Dipping teats with disinfectant and drying, prior to milking, was associated with lower numbers of Streptococcus/Enterococcus spp. in milk. Disinfecting clusters between milking different cows was associated with a reduction in thermophilic and psychrotrophic counts in milk. This study did not provide evidence that use of RMS bedding increased the risk of presence of Y. enterocolitica, Salmonella spp. or L. monocytogenes in milk. However, the strength of this conclusion should be tempered by the relatively small number of farms on which Y. enterocolitica and Salmonella spp. were isolated. It is concluded that, despite the higher bacterial load of RMS, its use as bedding for lactating dairy cows need not be associated with a higher bacterial load in milk than the use of sand or sawdust. However, this finding must be interpreted in the light of the relatively recent introduction of RMS as a bedding material on the farms studied. Teat preparation provides a control point for the potential transfer of microorganisms from bedding to milk. The detection of zoonotic pathogens in a small proportion of milk samples, independent of bedding type, indicates that pasteurisation of milk prior to human consumption remains an important control measure.

      PubDate: 2018-02-04T21:46:22Z
      DOI: 10.1016/j.ijfoodmicro.2017.12.022
      Issue No: Vol. 269 (2018)
       
  • Characterisation of ail-positive Yersinia enterocolitica of different
           biotypes using HRMA
    • Authors: Agata Bancerz-Kisiel; Anna Szczerba-Turek; Aleksandra Platt-Samoraj; Maria Michalczyk; Wojciech Szweda
      Pages: 46 - 51
      Abstract: Publication date: 23 March 2018
      Source:International Journal of Food Microbiology, Volume 269
      Author(s): Agata Bancerz-Kisiel, Anna Szczerba-Turek, Aleksandra Platt-Samoraj, Maria Michalczyk, Wojciech Szweda
      Yersiniosis is one of the four most frequent foodborne zoonotic diseases in Europe, and Yersinia enterocolitica is the primary agent in human infections. The ail gene is an important chromosomal virulence marker of Y. enterocolitica which encodes Ail, a 17-kDa outer membrane protein that promotes attachment and invasion. In the present study, ail-positive Y. enterocolitica strains of different biotypes were examined using high resolution melting analysis (HRMA) and DNA sequencing. Genotype data relating to Y. enterocolitica strains isolated from different sources and belonging to different biotypes were compared. Applied method allowed efficient distinguishing of three genotypes and phylogenetic groups: 1A – included non-pathogenic Y. enterocolitica strains; 1B – consisted of highly pathogenic Y. enterocolitica strains and 2/4 – involved weakly pathogenic Y. enterocolitica strains. Amplicon genotyping based on HRMA supports rapid identification of ail SNPs correlated with biotype of examined Y. enterocolitica strains.

      PubDate: 2018-02-04T21:46:22Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.016
      Issue No: Vol. 269 (2018)
       
  • Ability of Shiga toxigenic Escherichia coli to survive within dry-surface
           biofilms and transfer to fresh lettuce
    • Authors: Emelia Hornam Adator; Meining Cheng; Rick Holley; Tim McAllister; Claudia Narvaez-Bravo
      Pages: 52 - 59
      Abstract: Publication date: 23 March 2018
      Source:International Journal of Food Microbiology, Volume 269
      Author(s): Emelia Hornam Adator, Meining Cheng, Rick Holley, Tim McAllister, Claudia Narvaez-Bravo
      Biofilms are known to play important roles in bacterial survival and persistence in food-processing environments. This study aimed to determine the ability of the top 7 STEC serotypes to form biofilms on polystyrene (POL) and stainless steel (SS) plates and to quantify their survival and transfer from dry-surface biofilms to lettuce pieces. The ability of 14 STEC strains to form biofilms on these two materials at different exposure times and temperatures was assessed using crystal violet, Congo red and SEM. At 10 °C all serotypes were weak biofilm producers on both surfaces. In contrast, serotypes O45-040, O45-445, O103-102, O103-670 and O157-R508 were strong biofilm producers at 25 °C. Strains O103-102, O103-670, O111-CFS, O111–053 and O157:H7-R508 were expressers of curli. Under scanning electron microscopy, strains O103-670, O111-CFS, O157-R508, and O121-083 formed more discernible multilayer, mature biofilms on SS coupons. Regardless of the surface (POL/SS), all STEC strains were able to transfer viable cells onto fresh lettuce within a short contact time (2 min) to varying degrees (up to 6.35 log cfu/g). On POL, viable cell of almost all serotypes exhibited decreased detachment (p = 0.001) over 6 days; while after 30 days on SS, serotypes O45-040, O103-102, O103-670, O111-053, O111-CFS, O121-083, O145-231 O157:H7-R508 and O157:H7-122 were transferred to lettuce. After enrichment, all 14 STEC strains were recovered from dry-surface biofilms on POL and SS plates after 30 days. Results demonstrated that the top 7 STEC remained viable within dry-surface biofilms for at least 30 days, transferring to lettuce within 2 min of exposure and acting as a source of adulteration.

      PubDate: 2018-02-04T21:46:22Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.014
      Issue No: Vol. 269 (2018)
       
  • Emergence of plasmid-mediated colistin-resistance in CMY-2-producing
           Escherichia coli of lineage ST2197 in a Tunisian poultry farm
    • Authors: Elaa Maamar; Carla Andrea Alonso; Zaineb Hamzaoui; Nouha Dakhli; Mohamed Salah Abbassi; Sana Ferjani; Mabrouka Saidani; Ilhem Boutiba-Ben Boubaker; Carmen Torres
      Pages: 60 - 63
      Abstract: Publication date: 23 March 2018
      Source:International Journal of Food Microbiology, Volume 269
      Author(s): Elaa Maamar, Carla Andrea Alonso, Zaineb Hamzaoui, Nouha Dakhli, Mohamed Salah Abbassi, Sana Ferjani, Mabrouka Saidani, Ilhem Boutiba-Ben Boubaker, Carmen Torres
      Our study aimed to investigate colistin resistance and the mechanisms involved in a collection of 35 extended-spectrum beta-lactamase (ESBL) and 13 CMY-2-producing E. coli strains which were previously recovered from chicken gut microbiota in Tunisia, as well as to determine the genetic location of mcr genes. Forty-eight ESBL and CMY-2-producing E. coli strains were obtained from 137 fecal samples of healthy chickens during 2013. These strains were tested for colistin resistance by the broth microdilution method, and screened for mcr-1 and mcr-2 genes by PCR. Two of these strains were colistin-resistant (MIC = 8 mg/L). Both harbored the mcr-1 gene, were CMY-2 producers, and were additionally resistant to tetracycline, ciprofloxacin, chloramphenicol, gentamicin, tobramycin and trimethoprim-sulfamethoxazole. They shared phylogroup A, the same pulsed-field gel electrophoresis (PFGE)-pattern, and were typed as ST2197. In both strains, ISApl1 and pap2 were detected upstream and downstream of mcr-1 gene, respectively. The analysis of the two mcr-1-positive strains and their transconjugants by PCR-based replicon typing and S1-PFGE, demonstrated that mcr-1 gene is linked to an IncP plasmid (~242 kb), and bla CMY-2 to an IncI1 plasmid (97 kb). The occurrence of E. coli harboring mcr-1 gene among intestinal microbiota in poultry and its location on a conjugative plasmid could represent a risk for public health. The evolution of this type of resistant microorganisms should be evaluated in the future.

      PubDate: 2018-02-15T19:45:16Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.017
      Issue No: Vol. 269 (2018)
       
  • Discrimination of infectious and heat-treated norovirus by combining
           platinum compounds and real-time RT-PCR
    • Authors: Audrey Fraisse; Florian Niveau; Catherine Hennechart-Collette; Coralie Coudray-Meunier; Sandra Martin-Latil; Sylvie Perelle
      Pages: 64 - 74
      Abstract: Publication date: 23 March 2018
      Source:International Journal of Food Microbiology, Volume 269
      Author(s): Audrey Fraisse, Florian Niveau, Catherine Hennechart-Collette, Coralie Coudray-Meunier, Sandra Martin-Latil, Sylvie Perelle
      Human noroviruses (NoV) are major agents of foodborne outbreaks. Because of the lack of a standardized cell culture method, real-time reverse transcriptase PCR is now commonly used for the detection of NoV in foodstuffs and environmental samples. However, this approach detects the viral nucleic acids of both infectious and non-infectious viruses and needs to be optimized to predict infectivity for public health risk assessment. The aim of this study was to develop a viability PCR method to discriminate between native and heat-treated virus, for both NoV and its surrogate, murine norovirus (MNV). To this end, screening of viability markers (monoazide dyes, platinum and palladium compounds) was performed on viral RNA, native virus or heat-treated virus, and incubation conditions were optimized with PtCl4, the most efficient viability marker. Multiple MNV molecular models were designed: no impact of amplicon length was observed on inactivated MNV genomic titer; but the 5′NTR, ORF1 and 3′UTR regions resulted in higher reductions than central genomic regions. The optimal viability PCR conditions developed (incubation with 2.5 mM PtCl4 in PBS for 10 min at 5 °C) were finally applied to MNV by performing heat inactivation studies and to native and heat-treated NoV clinical strains. The viability PCR discriminated efficiently between native and heat-inactivated MNV at 72 °C and 80 °C, and efficiently reduced the genomic titer of heat-treated NoV strains. This viability PCR method could be useful to study heat inactivation kinetics of NoV and MNV. It could also be evaluated for the identification of infectious enteric viruses in foodstuffs and environmental samples.

      PubDate: 2018-02-04T21:46:22Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.015
      Issue No: Vol. 269 (2018)
       
  • Quantification of the Campylobacter contamination on broiler carcasses
           during the slaughter of Campylobacter positive flocks in
           semi-industrialized slaughterhouses
    • Authors: Christian Vinueza-Burgos; María Cevallos; Marco Cisneros; Inge Van Damme; Lieven De Zutter
      Pages: 75 - 79
      Abstract: Publication date: 23 March 2018
      Source:International Journal of Food Microbiology, Volume 269
      Author(s): Christian Vinueza-Burgos, María Cevallos, Marco Cisneros, Inge Van Damme, Lieven De Zutter
      Campylobacter contamination of broiler carcasses has been little studied in semi-industrialized slaughterhouses in developing countries, where several steps are carried out manually or with limited technology. In this study, we performed quantification of the Campylobacter contamination on carcasses at four steps in the slaughter process in three Ecuadorian slaughterhouses. Therefore, 15 Campylobacter positive batches were sampled in three commercial slaughterhouses. For every batch, caecal content and five samples of breast skin were taken and examined for Campylobacter counts at the following steps: after plucking, after evisceration, after final washing and after water chilling. Slaughterhouse C was the only slaughterhouse in which Campylobacter counts increased significantly after evisceration. No significant differences were found between counts after evisceration and after final washing (P > 0.05). In all slaughterhouses, a significant reduction of Campylobacter counts (0.11 to 2.55 log10 CFU/g) was found after the chilling step. The presence of chlorine in the chilling water was associated with the highest reduction in Campylobacter counts on the carcasses. A high variability of Campylobacter counts was found within and between batches slaughtered in the same slaughterhouse. Campylobacter counts in caecal content samples were not correlated with counts on carcasses after plucking nor after evisceration.

      PubDate: 2018-02-04T21:46:22Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.021
      Issue No: Vol. 269 (2018)
       
  • Increased exposure to extended-spectrum β-lactamase-producing
           multidrug-resistant Enterobacteriaceae through the consumption of chicken
           and sushi products
    • Authors: Ana Isabel Vitas; Dixita Naik; Lara Pérez-Etayo; David González
      Pages: 80 - 86
      Abstract: Publication date: 23 March 2018
      Source:International Journal of Food Microbiology, Volume 269
      Author(s): Ana Isabel Vitas, Dixita Naik, Lara Pérez-Etayo, David González
      The aim of this study was to determine the occurrence and patterns of resistance of extended-spectrum β-lactamase (ESBL) producing Enterobacteriaceae in food products purchased in Navarra, northern Spain. A total of 174 samples of fish and chicken were analyzed from September 2015 to September 2016, including raw and ready-to-eat products: trout (n = 25), salmon (n = 28), panga (n = 13), chicken nuggets and chicken scalopes (n = 32), sushi (n = 31) and sliced cooked poultry (n = 45). Cefpodoxime-resistant strains were isolated on ChromID ESBL agar and further phenotypic (antimicrobial study on MicroScan© NM37 panel) and genotypic characterization (multiplex PCR, sequencing and multi-locus sequence typing, MLST) was performed to confirm and characterize ESBL producers. Raw chicken and sushi have been determined as the most risky products regarding transmission of ESBL-producing Enterobacteriaceae (occurrence 53.1% and 19.4%, respectively), while sliced cooked poultry products appear to be a safe product in this aspect. With regard to raw fish, prevalence in salmon was lower (3.6%) than in trout and panga (16.0%). Ninety-eight per cent of ESBL isolates (n = 50) show multidrug-resistant profiles, highlighting the high resistances against quinolones and tetracyclines observed in chicken isolates, as well as against ertapenem and chloramphenicol in sushi strains. Predominant β-lactamase type was SHV-12 (50.1%), followed by TEM-type (24.5%) and CTX-M (20.8%). In addition, CTX-M type was only detected in chicken products. The phylogenetic study showed the prevalence of groups A (35%), F (25%) and B1 (15%), usually related to nonvirulent strains. MLST E. coli isolates (n = 20) were grouped into 5 clonal complexes (CC) and 15 sequence types (ST), showing high clonal diversity. ST117 was the prevalent sequence type, while the human pathogen ST131 was not detected in this study. The high prevalence of ESBL-producing multidrug-resistant Enterobacteriaceae detected in products of widespread consumption such as chicken and sushi, increases the concern regarding human exposure to superbugs and encourages the need to improve surveillance of this public health issue.

      PubDate: 2018-02-15T19:45:16Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.026
      Issue No: Vol. 269 (2018)
       
  • Alternative patulin pathway unproven
    • Authors: R. Russell M. Paterson; Célia Soares; Salma Ouhibi; Nelson Lima
      Pages: 87 - 88
      Abstract: Publication date: 23 March 2018
      Source:International Journal of Food Microbiology, Volume 269
      Author(s): R. Russell M. Paterson, Célia Soares, Salma Ouhibi, Nelson Lima


      PubDate: 2018-02-04T21:46:22Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.019
      Issue No: Vol. 269 (2018)
       
  • Identifying possible non-thermal effects of radio frequency energy on
           inactivating food microorganisms
    • Authors: Xiaoxi Kou; Rui Li; Lixia Hou; Lihui Zhang; Shaojin Wang
      Pages: 89 - 97
      Abstract: Publication date: 23 March 2018
      Source:International Journal of Food Microbiology, Volume 269
      Author(s): Xiaoxi Kou, Rui Li, Lixia Hou, Lihui Zhang, Shaojin Wang
      Radio frequency (RF) heating has been successfully used for inactivating microorganisms in agricultural and food products. Athermal (non-thermal) effects of RF energy on microorganisms have been frequently proposed in the literature, resulting in difficulties for developing effective thermal treatment protocols. The purpose of this study was to identify if the athermal inactivation of microorganisms existed during RF treatments. Escherichia coli and Staphylococcus aureus in apple juice and mashed potato were exposed to both RF and conventional thermal energies to compare their inactivation populations. A thermal death time (TDT) heating block system was used as conventional thermal energy source to simulate the same heating treatment conditions, involving heating temperature, heating rate and uniformity, of a RF treatment at a frequency of 27.12 MHz. Results showed that a similar and uniform temperature distribution in tested samples was achieved in both heating systems, so that the central sample temperature could be used as representative one for evaluating thermal inactivation of microorganisms. The survival patterns of two target microorganisms in two food samples were similar both for RF and heating block treatments since their absolute difference of survival populations was <1 log CFU/ml. The statistical analysis indicated no significant difference (P > 0.05) in inactivating bacteria between the RF and the heating block treatments at each set of temperatures. The solid temperature and microbial inactivation data demonstrated that only thermal effect of RF energy at 27.12 MHz was observed on inactivating microorganisms in foods.

      PubDate: 2018-02-04T21:46:22Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.025
      Issue No: Vol. 269 (2018)
       
  • Sequential effect of phages and cold nitrogen plasma against Escherichia
           coli O157:H7 biofilms on different vegetables
    • Authors: Haiying Cui; Mei Bai; Lu Yuan; Duraiarasan Surendhiran; Lin Lin
      Pages: 1 - 9
      Abstract: Publication date: 2 March 2018
      Source:International Journal of Food Microbiology, Volume 268
      Author(s): Haiying Cui, Mei Bai, Lu Yuan, Duraiarasan Surendhiran, Lin Lin
      Escherichia coli O157:H7 (E. coli O157:H7) is one of the most common pathogens in fresh vegetables and fruits, and most of the diseases produced by E. coli O157:H7 are associated with biofilms. Cold nitrogen plasma (CNP) is a cold sterilization technique which has no residue. However to completely eliminate the biofilm on the surface of vegetables the processing power and time of CNP have to be enhanced, which will impact on the quality of fruits and vegetables. Thus the sequential treatment of CNP and phage techniques was engineered in this study. Compared to treatment performed separately, sequential treatment not only had more mild treatment conditions as 400W CNP treatment for 2min and 5% phage treatment for 30min, but also exhibited more remarkable effect on eradicating E. coli O157:H7 biofilms in vitro and on vegetables. The population of E. coli O157:H7 was approximately reduced by 2logCFU/cm2 after individual treatment of 5% phages for 30min or 500W CNP for 3min. While the sequential treatment of CNP (400W, 2min) and phages (5%, 30min) reduced the E. coli O157:H7 viable count in biofilm by 5.71logCFU/cm2. Therefore, the sequential treatment holds a great promise to improve the current treatment systems of bacterial contamination on different vegetable surfaces.

      PubDate: 2018-01-05T12:22:13Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.004
      Issue No: Vol. 268 (2018)
       
  • Anisakis spp. larvae in different kinds of ready to eat products made of
           anchovies (Engraulis encrasicolus) sold in Italian supermarkets
    • Authors: L. Guardone; D. Nucera; L.B. Lodola; L. Tinacci; P.L. Acutis; A. Guidi; A. Armani
      Pages: 10 - 18
      Abstract: Publication date: 2 March 2018
      Source:International Journal of Food Microbiology, Volume 268
      Author(s): L. Guardone, D. Nucera, L.B. Lodola, L. Tinacci, P.L. Acutis, A. Guidi, A. Armani
      In this study the occurrence of visible anisakid larvae in semi-preserved anchovy products sold on the Italian market was investigated. Totally, 107 ready to eat products (33 salted-ripened, 49 in oil and 25 marinated) were sampled. Each sample was digested, then the digested material was observed under natural and UV light. Parasites were counted, collected and microscopically identified to genus level. A representative subset was molecularly identified using the cox2 gene. At least one visible Anisakis sp. larva was found in 54.2% of the total 107 products analysed and totally 1283 dead larvae were collected. Anisakis sp. larvae were found in all the 33 salted products and 1139 (88.8%) larvae were collected, with a range of 1–105 parasites per product. Larval density per gram was 0.13. Anisakis sp. larvae were found in 49.0% of the products in oil and 143 (11.1%) larvae were isolated, with a range of 0–28 and a density of 0.03. Only 1 larva was found in the 25 marinated products (4.0%, density 0.00). A highly significant difference between all the product categories in respect of number of larvae per product, frequency of products contaminated by at least one larva and larval density per gram was found. Within the subset of larvae molecularly analysed (n =122), 92 (75.4%) were identified as A. pegreffii and 30 (24.6%) as A. simplex. This study showed that semi-preserved anchovy products heavily contaminated with Anisakis spp. larvae reach the market. Beyond the negligible risk for anisakidosis, the presence of dead visible parasites may cause immediate rejection in consumers. In addition, the potential risk related to allergic reactions in sensitized individuals needs to be further assessed. In order to avoid commercialization of obviously contaminated products, fresh anchovies' batches intended for the production of such products should be accurately selected by the processing industry applying inspection methods.

      PubDate: 2018-01-05T12:22:13Z
      DOI: 10.1016/j.ijfoodmicro.2017.12.030
      Issue No: Vol. 268 (2018)
       
  • Development of novel quinoa-based yoghurt fermented with dextran producer
           Weissella cibaria MG1
    • Authors: Emanuele Zannini; Stephanie Jeske; Kieran M. Lynch; Elke K. Arendt
      Pages: 19 - 26
      Abstract: Publication date: 2 March 2018
      Source:International Journal of Food Microbiology, Volume 268
      Author(s): Emanuele Zannini, Stephanie Jeske, Kiran Lynch, Elke K. Arendt
      The aim of this study was to develop a novel beverage fermented with Weissella cibaria MG1 based on aqueous extracts of wholemeal quinoa flour. The protein digestibility of quinoa based-milk was improved by applying complex proteolytic enzymes able to increase protein solubility by 54.58%. The growth and fermentation characteristics of Weissella cibaria MG1, including EPS production at the end of fermentation, were investigated. Fermented wholemeal quinoa milk using MG1 showed high viable cell counts (>109 cfu/ml), a pH of 5.16, and significantly higher water holding capacity (WHC, 100%), viscosity (0.57mPas) and exopolysaccharide (EPS) amount (40mg/l) than the chemical acidified control. High EPS (dextran) concentration in quinoa milk caused earlier aggregation because more EPS occupy more space, and the chenopodin were forced to interact with each other. Microstructure observation indicated that the network structures of EPS-protein improve the texture of fermented quinoa milk. Overall, Weissella cibaria MG1 showed satisfactory technology properties and great potential for further possible application in the development of high viscosity fermented quinoa milk.

      PubDate: 2018-01-09T19:53:36Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.001
      Issue No: Vol. 268 (2018)
       
  • Expression of heterologous transporters in Saccharomyces kudriavzevii: A
           strategy for improving yeast salt tolerance and fermentation performance
    • Authors: Hana Dibalova-Culakova; Javier Alonso-del-Real; Amparo Querol; Hana Sychrova
      Pages: 27 - 34
      Abstract: Publication date: 2 March 2018
      Source:International Journal of Food Microbiology, Volume 268
      Author(s): Hana Dibalova-Culakova, Javier Alonso-del-Real, Amparo Querol, Hana Sychrova
      S. kudriavzevii has potential for fermentations and other biotechnological applications, but is sensitive to many types of stress. We tried to increase its tolerance and performance via the expression of various transporters from different yeast species. Whereas the overexpression of Z. rouxii fructose uptake systems (ZrFfz1 and ZrFsy1) or a glycerol importer (ZrStl1) did not improve the ability of S. kudriavzevii to consume fructose and survive osmotic stress, the expression of alkali-metal-cation exporters (ScEna1, ScNha1, YlNha2) improved S. kudriavzevii salt tolerance, and that of ScNha1 also the fermentation performance. The level of improvement depended on the type and activity of the transporter suggesting that the natural sensitivity of S. kudriavzevii cells to salts is based on a non-optimal functioning of its own transporters.

      PubDate: 2018-01-09T19:53:36Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.002
      Issue No: Vol. 268 (2018)
       
  • Description of an orthologous cluster of ochratoxin A biosynthetic genes
           in Aspergillus and Penicillium species. A comparative analysis
    • Authors: Jessica Gil-Serna; Marta García-Díaz; María Teresa González-Jaén; Covadonga Vázquez; Belén Patiño
      Pages: 35 - 43
      Abstract: Publication date: 2 March 2018
      Source:International Journal of Food Microbiology, Volume 268
      Author(s): Jessica Gil-Serna, Marta García-Díaz, María Teresa González-Jaén, Covadonga Vázquez, Belén Patiño
      Ochratoxin A (OTA) is one of the most important mycotoxins due to its toxic properties and worldwide distribution which is produced by several Aspergillus and Penicillium species. The knowledge of OTA biosynthetic genes and understanding of the mechanisms involved in their regulation are essential. In this work, we obtained a clear picture of biosynthetic genes organization in the main OTA-producing Aspergillus and Penicillium species (A. steynii, A. westerdijkiae, A. niger, A. carbonarius and P. nordicum) using complete genome sequences obtained in this work or previously available on databases. The results revealed a region containing five ORFs which predicted five proteins: halogenase, bZIP transcription factor, cytochrome P450 monooxygenase, non-ribosomal peptide synthetase and polyketide synthase in all the five species. Genetic synteny was conserved in both Penicillium and Aspergillus species although genomic location seemed to be different since the clusters presented different flanking regions (except for A. steynii and A. westerdijkiae); these observations support the hypothesis of the orthology of this genomic region and that it might have been acquired by horizontal transfer. New real-time RT-PCR assays for quantification of the expression of these OTA biosynthetic genes were developed. In all species, the five genes were consistently expressed in OTA-producing strains in permissive conditions. These protocols might favour futures studies on the regulation of biosynthetic genes in order to develop new efficient control methods to avoid OTA entering the food chain.

      PubDate: 2018-01-09T19:53:36Z
      DOI: 10.1016/j.ijfoodmicro.2017.12.028
      Issue No: Vol. 268 (2018)
       
  • Mycotoxin production of Alternaria strains isolated from Korean barley
           grains determined by LC-MS/MS
    • Authors: Thuong T.T. Nguyen; Jueun Kim; Sun Jeong Jeon; Chul Won Lee; Naresh Magan; Hyang Burm Lee
      Pages: 44 - 52
      Abstract: Publication date: 2 March 2018
      Source:International Journal of Food Microbiology, Volume 268
      Author(s): Thuong T.T. Nguyen, Jueun Kim, Sun Jeong Jeon, Chul Won Lee, Naresh Magan, Hyang Burm Lee
      Twenty-four Alternaria strains were isolated from barley grain samples. These strains were screened for the production of mycotoxins on rice medium using thin layer chromatography. All 24 strains produced at least one of the five mycotoxins (ALT, AOH, ATX-I, AME, and TeA). Three representative strains, namely EML-BLDF1-4, EML-BLDF1-14, and EML-BLDF1-18, were further analyzed using a new LC–MS/MS-based mycotoxin quantification method. This method was used to detect and quantify Alternaria mycotoxins. We used positive ion electrospray mass spectrometry with multiple reaction mode (MRM) for the simultaneous quantification of various Alternaria mycotoxins produced by these strains. Five Alternaria toxins (ALT, ATX-I, AOH, AME, and TeA) were detected and quantified. Sample preparation included methanol extraction, concentration, and injection into LC–MS/MS. Limit of detection ranged from 0.13 to 4μg/mL and limit of quantification ranged from 0.25 to 8μg/mL.

      PubDate: 2018-01-09T19:53:36Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.003
      Issue No: Vol. 268 (2018)
       
  • Diversity of Aspergillus section Nigri on the surface of Vitis labrusca
           and its hybrid grapes
    • Authors: Larissa de Souza Ferranti; Maria Helena P. Fungaro; Fernanda Pelisson Massi; Josué José da Silva; Rafael Elias Silva Penha; Jens Christian Frisvad; Marta Hiromi Taniwaki; Beatriz Thie Iamanaka
      Pages: 53 - 60
      Abstract: Publication date: 2 March 2018
      Source:International Journal of Food Microbiology, Volume 268
      Author(s): Larissa de Souza Ferranti, Maria Helena P. Fungaro, Fernanda Pelisson Massi, Josué José da Silva, Rafael Elias Silva Penha, Jens Christian Frisvad, Marta Hiromi Taniwaki, Beatriz Thie Iamanaka
      This study investigated the presence of Aspergillus species belonging to Aspergillus section Nigri on Vitis labrusca and its hybrid grapes grown in Brazil. The ability of the fungi isolates to produce ochratoxin A (OTA) and fumonisin B2 (FB2) as well as the presence of these mycotoxins in the grapes were also studied. Eighty-eight samples were collected from the main grape producing states in Brazil: Rio Grande do Sul (n =30), Pernambuco (n =21), São Paulo (n =21) and Paraná (n =16). The highest average contamination level by A. section Nigri occurred on the grapes from Pernambuco (66.3%). A total of 2042 A. section Nigri isolates was analyzed and clustered in three groups according to morphology characterization: A. section Nigri uniseriate (79.3%), A. niger “aggregate” (18.3%) and A. carbonarius (2.4%). In order to precisely identify the Aspergillus species, two hundred and forty-eight strains were subjected to DNA sequencing. Among the A. section Nigri uniseriate group, the following species were found: A. japonicus, A. uvarum, A. brunneoviolaceus, A. aculeatus and A. labruscus. Within the A. niger “aggregate”, the following species were found: A.niger sensu stricto, A. welwitschiae and A. vadensis. Regarding mycotoxin-production capacity, 3.2% of the total A. section Nigri isolates (2042) were positive for OTA production and from A. niger “aggregate” (373) tested, 42.1% were FB2 producers. However, none of the 88 grape samples were contaminated with these mycotoxins.

      PubDate: 2018-01-27T09:09:06Z
      DOI: 10.1016/j.ijfoodmicro.2017.12.027
      Issue No: Vol. 268 (2018)
       
  • Genomic and metabolic characterization of spoilage-associated Pseudomonas
           species
    • Authors: Tamsyn Stanborough; Narelle Fegan; Shane M. Powell; Tanoj Singh; Mark Tamplin; P. Scott Chandry
      Pages: 61 - 72
      Abstract: Publication date: 2 March 2018
      Source:International Journal of Food Microbiology, Volume 268
      Author(s): Tamsyn Stanborough, Narelle Fegan, Shane M. Powell, Tanoj Singh, Mark Tamplin, P. Scott Chandry
      Pseudomonas are common spoilage agents of aerobically stored fresh foods. Their ability to cause spoilage is species- and may be strain-specific. To improve our understanding of the meat and milk spoilage agents Pseudomonas fragi and Pseudomonas lundensis, we sequenced the genomes of 12 P. fragi and seven P. lundensis isolates. These genomes provided a dataset for genomic analyses. Key volatile organic compounds (VOCs) produced or metabolised by the isolates were determined during their growth on a beef paste and where possible, metabolic activity was associated with gene repertoire. Genome analyses showed that the isolates included in this work may belong to more than two Pseudomonas species with possible spoilage potential. Pan-genome analyses demonstrated a high degree of diversity among the P. fragi and genetic flexibility and diversity may be traits of both species. Growth of the P. lundensis isolates was characterised by the production of large amounts of 1-undecene, 5-methyl-2-hexanone and methyl-2-butenoic acid. P. fragi isolates produced extensive amounts of methyl and ethyl acetate and the production of methyl esters predominated over ethyl esters. Some of the P. fragi produced extremely low levels of VOCs, highlighting the importance of strain-specific studies in food matrices. Furthermore, although usually not considered to be denitrifiers, all isolates generated molecular nitrogen, indicating that at least some steps of this pathway are intact.

      PubDate: 2018-01-27T09:09:06Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.005
      Issue No: Vol. 268 (2018)
       
  • Potential of yeasts isolated from dry-cured ham to control ochratoxin A
           production in meat models
    • Authors: Belén Peromingo; Félix Núñez; Alicia Rodríguez; Alberto Alía; María J. Andrade
      Pages: 73 - 80
      Abstract: Publication date: 2 March 2018
      Source:International Journal of Food Microbiology, Volume 268
      Author(s): Belén Peromingo, Félix Núñez, Alicia Rodríguez, Alberto Alía, María J. Andrade
      The environmental conditions reached during the ripening of dry-cured meat products favour the proliferation of moulds on their surface. Some of these moulds are hazardous to consumers because of their ability to produce ochratoxin A (OTA). Biocontrol using Debaryomyces hansenii could be a suitable strategy to prevent the growth of ochratoxigenic moulds and OTA accumulation in dry-cured meat products. The aim of this work was to evaluate the ability of two strains of D. hansenii to control the growth and OTA production of Penicillium verrucosum in a meat model under water activities (aw) values commonly reached during the dry-cured meat product ripening. The presence of D. hansenii strains triggered a lengthening of the lag phase and a decrease of the growth rate of P. verrucosum in meat-based media at 0.97 and 0.92 aw. Both D. hansenii strains significantly reduced OTA production (between 85.16 and 92.63%) by P. verrucosum in the meat-based medium at 0.92 aw. Neither absorption nor detoxification of OTA by D. hansenii strains seems to be involved. However, a repression of the expression of the non-ribosomal peptide synthetase (otanpsPN) gene linked to the OTA biosynthetic pathway was observed in the presence of D. hansenii. To confirm the protective role of D. hansenii strains, they were inoculated together with P. verrucosum Pv45 in dry-fermented sausage and dry-cured ham slices. Although P. verrucosum Pv45 counts were not affected by the presence of D. hansenii in both meat matrices, a reduction of OTA amount was observed. Therefore, the effect of D. hansenii strains on OTA accumulation should be attributed to a reduction at transcriptional level. Consequently, native D. hansenii can be useful as biocontrol agent in dry-cured meat products for preventing the hazard associated with the presence of OTA.

      PubDate: 2018-01-27T09:09:06Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.006
      Issue No: Vol. 268 (2018)
       
  • Effects of chitosan oligosaccharides on microbiota composition of silver
           carp (Hypophthalmichthys molitrix) determined by culture-dependent and
           independent methods during chilled storage
    • Authors: Shiliang Jia; Xiaochang Liu; Zhan Huang; Yan Li; Longteng Zhang; Yongkang Luo
      Pages: 81 - 91
      Abstract: Publication date: 2 March 2018
      Source:International Journal of Food Microbiology, Volume 268
      Author(s): Shiliang Jia, Xiaochang Liu, Zhan Huang, Yan Li, Longteng Zhang, Yongkang Luo
      This study evaluated the effects of chitosan oligosaccharides (COS) on the changes in quality and microbiota of silver carp fillets stored at 4 °C. During storage, 1% (w/v) COS treated samples maintained good quality, as evidenced by retarding sensory deterioration, inhibiting microbial growth, attenuating the production of total volatile basic nitrogen, putrescine, cadaverine and hypoxanthine, and delaying degradation of inosine monophosphate and hypoxanthine ribonucleotide. Meanwhile, variability in the predominant microbiota in different samples was investigated by culture-dependent and -independent methods. Based on sensory analysis, shelf-life of silver carp fillets was 4 days for the control and 6 days for COS treated samples. Meanwhile, Pseudomonas, followed by Aeromonas, Acinetobacter, and Shewanella were dominated in the control samples at day 4 and contributed to fish spoilage at day 6. However, COS inhibited the growth of Pseudomonas, Aeromonas, and Shewanella significantly. Consequently, Acinetobacter followed by Pseudomonas became the predominant microbiota in COS treated samples at day 6. With the growth of Pseudomonas, COS treated samples were spoiled at day 8. Therefore, COS improved the quality of fillets and prolonged the shelf life of silver carp fillets by 2 days during chilled storage, which was mainly due to their modulating effects on microbiota.

      PubDate: 2018-02-04T21:46:22Z
      DOI: 10.1016/j.ijfoodmicro.2018.01.011
      Issue No: Vol. 268 (2018)
       
  • Nematode parasites of commercially important fish from the southeast coast
           of Brazil: Morphological and genetic insight
    • Authors: Maria Isabel N. Di Azevedo; Alena M. Iñiguez
      Pages: 29 - 41
      Abstract: Publication date: 21 February 2018
      Source:International Journal of Food Microbiology, Volume 267
      Author(s): Maria Isabel N. Di Azevedo, Alena M. Iñiguez


      PubDate: 2018-01-05T12:22:13Z
      DOI: 10.1016/j.ijfoodmicro.2017.12.014
      Issue No: Vol. 267 (2018)
       
  • Autochthonous facility-specific microbiota dominates washed-rind Austrian
           hard cheese surfaces and its production environment
    • Authors: Narciso M. Quijada; Evelyne Mann; Martin Wagner; David Rodríguez-Lázaro; Marta Hernández; Stephan Schmitz-Esser
      Pages: 54 - 61
      Abstract: Publication date: 21 February 2018
      Source:International Journal of Food Microbiology, Volume 267
      Author(s): Narciso M. Quijada, Evelyne Mann, Martin Wagner, David Rodríguez-Lázaro, Marta Hernández, Stephan Schmitz-Esser
      Cheese ripening involves the succession of complex microbial communities that are responsible for the organoleptic properties of the final products. The food processing environment can act as a source of natural microbial inoculation, especially in traditionally manufactured products. Austrian Vorarlberger Bergkäse (VB) is an artisanal washed-rind hard cheese produced in the western part of Austria without the addition of external ripening cultures. Here, the composition of the bacterial communities present on VB rinds and on different processing surfaces from two ripening cellars was assessed by near full length 16S rRNA gene amplification, cloning and sequencing. Non-inoculated aerobic bacteria dominated all surfaces in this study. VB production conditions (long ripening time, high salt concentration and low temperatures) favor the growth of psychro- and halotolerant bacteria. Several bacterial groups, such as coryneforms, Staphylococcus equorum and Halomonas dominated VB and were also found on most environmental surfaces. Analysis of OTUs shared between different surfaces suggests that VB rind bacteria are inoculated naturally during the ripening from the processing environment and that cheese surfaces exert selective pressure on these communities, as only those bacteria better adapted flourished on VB rinds. This study analyzed VB processing environment microbiota and its relationship with VB rinds for the first time, elucidating that the processing environment and the cheese microbiota should be considered as microbiologically linked ecosystems with the goal of better defining the events that take place during cheese maturation.

      PubDate: 2018-01-05T12:22:13Z
      DOI: 10.1016/j.ijfoodmicro.2017.12.025
      Issue No: Vol. 267 (2018)
       
  • Species composition of and fumonisin production by the Fusarium fujikuroi
           species complex isolated from Korean cereals
    • Authors: Jung-Hye Choi; Seolhee Lee; Ju-Young Nah; Hee-Kyoung Kim; Ji-Seon Paek; Soohyung Lee; Hyeonheui Ham; Sung Kee Hong; Sung-Hwan Yun; Theresa Lee
      Pages: 62 - 69
      Abstract: Publication date: 21 February 2018
      Source:International Journal of Food Microbiology, Volume 267
      Author(s): Jung-Hye Choi, Seolhee Lee, Ju-Young Nah, Hee-Kyoung Kim, Ji-Seon Paek, Soohyung Lee, Hyeonheui Ham, Sung Kee Hong, Sung-Hwan Yun, Theresa Lee
      To assess the risk of fumonisin contamination in Korean cereals, we isolated colonies of the Fusarium fujikuroi species complex (FFSC) from barley, maize, rice and soybean samples from 2011 to 2015. A total of 878 FFSC strains were isolated mostly from maize and rice, and species identity of the isolates were determined using the DNA sequence of the translation elongation factor 1-α (TEF-1α) and RNA polymerase II (RPB2) genes. Fusaria recovered from Korean cereals included F. fujikuroi (317 isolates and a frequency of 36%), F. proliferatum (212 isolates and 24.1%), F. verticillioides (170 isolates and 19.4%), F. concentricum (86 strains and 9.8%), F. andiyazi (56 isolates and 6.4%), F. subglutinans (28 isolates and 3.2%), F. thapsinum (5 isolates and 0.6%), and F. circinatum (2 isolates and 0.2%). The rice samples were dominated by F. fujikuroi (47.4%), F. proliferatum (27.3%), and F. concentricum (15.1%), whereas maize samples were dominated by F. verticillioides (33.9%), F. fujikuroi (25.3%), and F. proliferatum (21.1%). A phylogenetic analysis of 70 representative isolates demonstrated that each species was resolved as genealogically exclusive in the ML tree. Fumonisin production potential was evaluated using a PCR assay for the fumonisin biosynthesis gene, FUM1 in all of the isolates. Most of the isolates tested (94%) were positive for FUM1. All of the isolates assigned to F. fujikuroi, F. proliferatum, F. verticillioides and F. thapsinum were positive for FUM1 irrespective of their host origin. Seventy-seven representative isolates positive for FUM1 were examined for fumonisin production in rice medium. The majority of F. proliferatum (26/27, 96.3%), F. verticillioides (16/17, 94.1%) and F. fujikuroi (19/25, 76.0%) produced both FB1 and FB2. Notably, 16 of 19 fumonisin-producing F. fujikuroi produced >1000μg/g of fumonisins (FB1 +FB2) in rice medium, which is higher than that in previous reports. These results suggest that F. fujikuroi can produce high levels of fumonisins similar to F. verticillioides and F. proliferatum.

      PubDate: 2018-02-15T19:45:16Z
      DOI: 10.1016/j.ijfoodmicro.2017.12.006
      Issue No: Vol. 267 (2018)
       
  • Modelling survival of Salmonella Enteritidis during storage of yoghurt at
           different temperatures
    • Authors: Derya Savran; Fernando Pérez-Rodríguez; A. Kadir Halkman
      Abstract: Publication date: Available online 15 February 2018
      Source:International Journal of Food Microbiology
      Author(s): Derya Savran, Fernando Pérez-Rodríguez, A. Kadir Halkman
      The aim of this study was to evaluate the behaviour of Salmonella Enteritidis during the storage of yoghurt at different temperatures (4, 12, 20, and 25 °C), and to develop mathematical models to predict the behaviour of this bacterium as a function of storage temperature. Results indicated that Salmonella was able to survive longer during storage when temperature was low (e.g. 304 h at 4 °C, 60 h at 25 °C). The Geeraerd model with log-decrease and tailing was selected as the most suitable model to describe survival. To evaluate the effect of storage temperature on kinetic parameters such as death rate (k max ) secondary models were developed. The k max was maximum at 25 °C and minimum at 4 °C with k max  = 0.28 and 0.039 h−1, respectively. The residual population (N res ) ranged 0.5 and 1.8 log CFU/g but there was no temperature dependency of this parameter. A probabilistic example was conduced based on the developed model to assess the exposure to Salmonella by consumption of traditional Turkish yoghurt.

      PubDate: 2018-02-15T19:45:16Z
      DOI: 10.1016/j.ijfoodmicro.2018.02.017
       
  • Role of RpoS in stress resistance, quorum sensing and spoilage potential
           of Pseudomonas fluorescens
    • Authors: Xiaoxiang Liu; Lei Ji; Xu Wang; Jianrong Li; Junli Zhu; Aihua Sun
      Abstract: Publication date: Available online 14 February 2018
      Source:International Journal of Food Microbiology
      Author(s): Xiaoxiang Liu, Lei Ji, Xu Wang, Jianrong Li, Junli Zhu, Aihua Sun
      Microorganism activities are considered the main cause of most food spoilage, leading to great economic losses. Pseudomonas fluorescens is a Gram-negative bacterium that is widely found in food and has high spoilage activity. RpoS is considered an important global regulator involved in stress survival and virulence in many pathogens. Thus, it is very possible that RpoS plays an important role in spoilage regulation in P. fluorescens. In this study an in-frame deletion mutation of rpoS was constructed to explore its function in P. fluorescens. The results showed that RpoS positively regulated the resistance of P. fluorescens to H2O2, heat, ethanol and crystal violet, negatively regulated the resistance to acetic acid, and had no effect on the resistance to NaCl. Further studies indicated that acylated homoserine lactone (AHL) production and the transcription levels of five AHL-related genes were significantly decreased in the rpoS mutant compared with those in the wild-type strain. Interestingly, the two homologous genes coding for AHL synthases contained RpoS-dependent −10 elements, suggesting that AHL quorum sensing is directly regulated by RpoS. RpoS also contributed to the spoilage activities of P. fluorescens by regulating extracellular protease and total volatile basic nitrogen (TVB-N) production in sterilized salmon juice. Our results reveal that RpoS was a key regulatory factor involved in stress resistance, the AHL quorum sensing system, and spoilage potential of P. fluorescens. Our study may benefit food safety control and food preservation.

      PubDate: 2018-02-15T19:45:16Z
      DOI: 10.1016/j.ijfoodmicro.2018.02.011
       
  • Metabolite profiling of Listeria innocua for unravelling the inactivation
           mechanism of electrolysed water by nuclear magnetic resonance spectroscopy
           
    • Authors: Qin Liu; Ji'en Wu; Zhi Yang Lim; Shaojuan Lai; Norman Lee; Hongshun Yang
      Abstract: Publication date: Available online 14 February 2018
      Source:International Journal of Food Microbiology
      Author(s): Qin Liu, Ji'en Wu, Zhi Yang Lim, Shaojuan Lai, Norman Lee, Hongshun Yang
      Bactericidal effects of low concentration electrolysed water (LcEW) on microorganisms are previously well reported; however, the inactivation mechanism of EW is not understood. The lethal and sublethal injuries of L. monocytogenes and L. innocua by EW treatments were determined and the metabolic profile changes for L. innocua were characterised using nuclear magnetic resonance (NMR). Microbial metabolomics approach combined with multivariate data analyses was used to interpret the cellular chemical fingerprints of L. innocua. The relative amount of intracellular reactive oxygen species (ROS) was assayed using 2′,7-dichlorodihydrofluorescein diacetate (H2DCFDA). The results showed that the proportion of the sublethally injured microbial cells L. monocytogenes and L. innocua increased from 40% to 70% and from 36% to 65%, respectively, when the free available chlorine (FAC) of LcEW increased from 2 to 8 mg/L. Overall, 36 low-molecular-weight metabolic compounds in L. innocua extracts were characterised by NMR spectroscopy. EW perturbation resulted in a drastic and multitude disruption across a wide range of biochemical process including peptidoglycan synthesis, nucleotides biosynthesis and amino acid metabolism. Elevated levels of α-ketoglutarate and succinate implicated the enhanced glutamate decarboxylase (GAD) system and γ-aminobutyric acid (GABA) shunt for the protection against oxidative stress. These findings provided the comprehensive insights into the metabolic response of Listeria to EW oxidative stress and can serve as a basis for better utilisation for sanitisation.

      PubDate: 2018-02-15T19:45:16Z
      DOI: 10.1016/j.ijfoodmicro.2018.02.014
       
  • Development of a qPCR assay for the detection of heat-resistant
           Talaromyces flavus
    • Authors: Jacek Panek; Magdalena Frąc
      Abstract: Publication date: Available online 13 February 2018
      Source:International Journal of Food Microbiology
      Author(s): Jacek Panek, Magdalena Frąc
      Heat-resistant fungi of the species Talaromyces flavus, which inhabits soil and can contaminate fruits, constitutes significant impact on spoilage of heat-processed food. T. flavus possess the ability to produce numerous mycotoxins and is able to survive the process of pasteurization what makes it a treat to food industry. Up to date there is no rapid and reliable method to detect and identify T. flavus. Therefore in this study, a sensitive method for detecting T. flavus was developed. The primers (Tf1_F/R) specific to detection of DNA replication licensing factor gene of T. flavus were designed. With this set of primers, a qPCR reaction with SybrGreen detection was developed. The specificity of assay with use of 5 T. flavus strains and 35 other fungal isolates was tested. The detection threshold was 200 fg of T. flavus genomic DNA. The developed method was able to detect 640 ascospores in 1 g of strawberry fruits and soil samples.
      Graphical abstract image

      PubDate: 2018-02-15T19:45:16Z
      DOI: 10.1016/j.ijfoodmicro.2018.02.010
       
  • Applicability of Lactococcus hircilactis and Lactococcus laudensis as
           dairy cultures
    • Authors: Flavio Tidona; Aurora Meucci; Milena Povolo; Valeria Pelizzola; Miriam Zago; Giovanna Contarini; Domenico Carminati; Giorgio Giraffa
      Abstract: Publication date: Available online 13 February 2018
      Source:International Journal of Food Microbiology
      Author(s): Flavio Tidona, Aurora Meucci, Milena Povolo, Valeria Pelizzola, Miriam Zago, Giovanna Contarini, Domenico Carminati, Giorgio Giraffa
      The aim of this study was to evaluate whether Lactococcus hircilactis and Lactococcus laudensis can be used as starter cultures. To this end, the two lactococci were characterized for traits of technological and functional interest. Tests in milk included growth at 20, 25, 30, and 37 °C, flavor production, antioxidant (AO) activity, folate and exopolysaccharide (EPS) production. At 30 °C, which resulted the best growth temperature for both strains, Lc. hircilactis and Lc. laudensis lowered the pH of the milk to 4.8 and 5.5, respectively, after 24 h of incubation. Sugar and organic acid composition indicated a higher lactose utilization, coupled with a higher lactate accumulation, by Lc. hircilactis, while galactose was completely consumed by both species. Both strains showed a Cit− phenotype after growth in a selective medium containing citrate as the sole carbon source. Nevertheless, a small amount of citrate was used by both lactococci when grown in milk. The two strains were characterized by a different flavor production, showed high AO activity, and produced small amounts of EPS (~30 mg/L). Lactococcus laudensis showed a weak proteolytic activity while Lc. hircilactis was able to accumulate folate at levels four times higher than uninoculated milk. When the two lactococci were tested as starter cultures in small-scale cheesemaking trials, cheeses resulted of satisfying quality and contained amounts of ethanol, acetic acid, diacetyl and acetoin higher than controls, obtained using a commercial culture. The application of Lc. hircilactis and Lc. laudensis as aromatic cultures in cheesemaking is proposed.

      PubDate: 2018-02-15T19:45:16Z
      DOI: 10.1016/j.ijfoodmicro.2018.02.015
       
  • A pan-European ring trial to validate an International Standard for
           detection of Vibrio cholerae, Vibrio parahaemolyticus and Vibrio
           vulnificus in seafoods
    • Authors: R.E. Hartnell; L. Stockley; W. Keay; J.-P. Rosseau; D. Hervio-Heath; H. Van der Berg; F. Leoni; U. Henigman; S. Denayer; B. Serbruyns; F. Georgsson; G. Krumova; C. Blanco; S. Copin; E. Strauch; K. Wieczorek; A. Britova; G. Hardouin; B. Lombard; P. in't Veld; A. Leclercq; C. Baker-Austin
      Abstract: Publication date: Available online 10 February 2018
      Source:International Journal of Food Microbiology
      Author(s): R.E. Hartnell, L. Stockley, W. Keay, J.-P. Rosseau, D. Hervio-Heath, H. Van der Berg, F. Leoni, U. Henigman, S. Denayer, B. Serbruyns, F. Georgsson, G. Krumova, C. Blanco, S. Copin, E. Strauch, K. Wieczorek, A. Britova, G. Hardouin, B. Lombard, P. in't Veld, A. Leclercq, C. Baker-Austin
      Globally, vibrios represent an important and well-established group of bacterial foodborne pathogens. The European Commission (EC) mandated the Comite de European Normalisation (CEN) to undertake work to provide validation data for 15 methods in microbiology to support EC legislation. As part of this mandated work programme, merging of ISO/TS 21872–1:2007, which specifies a horizontal method for the detection of V. parahaemolyticus and V. cholerae, and ISO/TS 21872–2:2007, a similar horizontal method for the detection of potentially pathogenic vibrios other than V. cholerae and V. parahaemolyticus) was proposed. Both parts of ISO/TS 21872 utilized classical culture-based isolation techniques coupled with biochemical confirmation steps. The work also considered simplification of the biochemical confirmation steps. In addition, because of advances in molecular based methods for identification of human pathogenic Vibrio spp. classical and real time PCR options were also included within the scope of the validation. These considerations formed the basis of a multi-laboratory validation study with the aim of improving the precision of this ISO technical specification and providing a single ISO standard method to enable detection of these important foodborne Vibrio spp.. To achieve this aim, an international validation study involving 13 laboratories from 9 countries in Europe was conducted in 2013. The results of this validation have enabled integration of the two existing technical specifications targeting the detection of the major foodborne Vibrio spp., simplification of the suite of recommended biochemical identification tests and the introduction of molecular procedures that provide both species level identification and discrimination of putatively pathogenic strains of V. parahaemolyticus by the determination of the presence of theromostable direct and direct related haemolysins. The method performance characteristics generated in this have been included in revised international standard, ISO 21872:2017, published in July 2017.

      PubDate: 2018-02-15T19:45:16Z
      DOI: 10.1016/j.ijfoodmicro.2018.02.008
       
  • Antifungal activity of plant-derived compounds and their synergism against
           major postharvest pathogens of longan fruit in vitro
    • Authors: P. Suwanamornlert; S. Sangchote; W. Chinsirikul; A. Sane; V. Chonhenchob
      Abstract: Publication date: Available online 10 February 2018
      Source:International Journal of Food Microbiology
      Author(s): P. Suwanamornlert, S. Sangchote, W. Chinsirikul, A. Sane, V. Chonhenchob
      The aim of this study was to find alternatives to conventional synthetic fungicides to control postharvest decay of longan fruit. The antifungal potential of thymol, carvacrol and trans-cinnamaldehyde was evaluated against four major longan pathogens, Lasiodiplodia spp., Phomopsis spp., Pestalotiopsis spp. and Geotrichum candidum, using vapor phase and direct contact methods. The vapor phase of all active compounds was more effective on fungal growth than direct contact. A volatile vapor of thymol and carvacrol had strong antifungal activity against the tested fungi, exhibiting minimum inhibitory concentration (MIC) in the range of 40 to 80 mg/L air; trans-cinnamaldehyde showed the least efficiency, with MIC ranging from 80 to 160 mg/L air for G. candidum and Phomopsis spp., while it could not inhibit Lasiodiplodia spp. and Pestalotiopsis spp. at 160 mg/L air. The minimum fungicidal concentration (MFC) of thymol and carvacrol varied from 40 to 80 mg/L air, while trans-cinnamaldehyde completely inhibited the mycelial growth of the tested fungi at higher concentrations. Mycelial growth of all tested fungi decreased with increasing active compound concentration, except for trans-cinnamaldehyde. Thymol proved to be the most effective compound against the four tested fungi, with effective concentration 50 (EC50) of 5.68 ± 0.59, 6.86 ± 0.52, 8.27 ± 0.22 and 9.99 ± 1.28 mg/L air for Lasiodiplodia spp., Phomopsis spp., Pestalotiopsis spp. and G. candidum, respectively. Fungal growth curves were adequately fitted (0.958 < R 2 < 0.996) by a modified Gompertz model. For all tested fungi, the lag phase (λ) of fungal mycelia exposed to thymol and carvacrol increased, while the maximum colony diameter (A) and maximum growth rate (v m ) decreased. A combination of thymol and carvacrol exhibited an antagonistic effect against G. candidum but an indifferent effect against Lasiodiplodia spp., Phomopsis spp. and Pestalotiopsis spp.

      PubDate: 2018-02-15T19:45:16Z
      DOI: 10.1016/j.ijfoodmicro.2018.02.009
       
  • Bacteriophages reduce Yersinia enterocolitica contamination of food and
           kitchenware
    • Authors: Jin Woo Jun; Se Chang Park; Anu Wicklund; Mikael Skurnik
      Abstract: Publication date: Available online 7 February 2018
      Source:International Journal of Food Microbiology
      Author(s): Jin Woo Jun, Se Chang Park, Anu Wicklund, Mikael Skurnik
      Yersinia enterocolitica, the primary cause of yersiniosis, is one of the most important foodborne pathogens globally and is associated with the consumption of raw contaminated pork. In the current study, four virulent bacteriophages (phages), one of Podoviridae (fHe-Yen3-01) and three of Myoviridae (fHe-Yen9-01, fHe-Yen9-02, and fHe-Yen9-03), capable of infecting Y. enterocolitica were isolated and characterized. fHe-Yen9-01 had the broadest host range (61.3% of strains, 65/106). It demonstrated a latent period of 35 min and a burst size of 33 plaque-forming units/cell, and was found to have a genome of 167,773 bp with 34.79% GC content. To evaluate the effectiveness of phage fHe-Yen9-01 against Y. enterocolitica O:9 strain Ruokola/71, we designed an experimental model of the food market environment. Phage treatment after bacterial inoculation of food samples, including raw pork (4 °C, 72 h), ready-to-eat pork (26 °C, 12 h), and milk (4 °C, 72 h), prevented bacterial growth throughout the experiments, with counts decreasing by 1–3 logs from the original levels of 2–4 × 103 CFU/g or ml. Similarly, when artificially contaminated kitchen utensils, such as wooden and plastic cutting boards and knives, and artificial hands, were treated with phages for 2 h, bacterial growth was effectively inhibited, with counts decreasing by 1–2 logs from the original levels of ca 104 CFU/cm2 or ml. To the best of our knowledge, this is the first report of the successful application of phages for the control of Y. enterocolitica growth in food and on kitchen utensils.

      PubDate: 2018-02-15T19:45:16Z
      DOI: 10.1016/j.ijfoodmicro.2018.02.007
       
  • Fermented meats (and the symptomatic case of the Flemish food pyramid):
           Are we heading towards the vilification of a valuable food group'
    • Authors: Frédéric Leroy; Teresa Aymerich; Marie-Christine Champomier-Vergès; Luca Cocolin; Luc De Vuyst; Mónica Flores; Françoise Leroi; Sabine Leroy; Régine Talon; Rudi F. Vogel; Monique Zagorec
      Abstract: Publication date: Available online 5 February 2018
      Source:International Journal of Food Microbiology
      Author(s): Frédéric Leroy, Teresa Aymerich, Marie-Christine Champomier-Vergès, Luca Cocolin, Luc De Vuyst, Mónica Flores, Françoise Leroi, Sabine Leroy, Régine Talon, Rudi F. Vogel, Monique Zagorec


      PubDate: 2018-02-15T19:45:16Z
      DOI: 10.1016/j.ijfoodmicro.2018.02.006
       
  • ICFMH Announcement
    • Abstract: Publication date: 2 March 2018
      Source:International Journal of Food Microbiology, Volume 268


      PubDate: 2018-02-04T21:46:22Z
       
  • Risk management of ochratoxigenic fungi and ochratoxin A in maize grains
           by bioactive EVOH films containing individual components of some essential
           oils
    • Authors: Andrea Tarazona; José V. Gómez; Rafael Gavara; Rufino Mateo-Castro; José V. Gimeno-Adelantado; Misericordia Jiménez; Eva M. Mateo
      Abstract: Publication date: Available online 3 February 2018
      Source:International Journal of Food Microbiology
      Author(s): Andrea Tarazona, José V. Gómez, Rafael Gavara, Rufino Mateo-Castro, José V. Gimeno-Adelantado, Misericordia Jiménez, Eva M. Mateo
      Aspergillus steynii and Aspergillus tubingensis are possibly the main ochratoxin A (OTA) producing species in Aspergillus section Circumdati and section Nigri, respectively. OTA is a potent nephrotoxic, teratogenic, embryotoxic, genotoxic, neurotoxic, carcinogenic and immunosuppressive compound being cereals the first source of OTA in the diet. In this study bioactive ethylene-vinyl alcohol copolymer (EVOH) films containing cinnamaldehyde (CINHO), linalool (LIN), isoeugenol (IEG) or citral (CIT) which are major components of some plant essential oils (EOs) were produced and tested against A. steynii and A. tubingensis growth and OTA production in partly milled maize grains. Due to the favourable safety profile, these bioactive compounds are considered in the category “GRAS”. The study was carried out under different water activity (0.96 and 0.99 aw), and temperature (24 and 32 °C) conditions. ANOVA showed that class of film, fungal species, aw and temperature and their interactions significantly affected growth rates (GR), ED50 and ED90 and the doses for total fungal growth inhibition and OTA production. The most effective EVOH films against both species were those containing CINHO. ED50, ED90 and doses for total growth and OTA inhibition were 165–405, 297–614, 333–666 μg of EVOH-CINHO/plate (25 g of maize grains), respectively, depending on environmental conditions. The least efficient were EVOH-LIN films. ED50, ED90 and doses for total growth and OTA inhibition were 2800–>3330, >3330 and >3330 μg of EVOH-LIN/plate (25 g of maize grains), respectively. The effectiveness of the bioactive films increased with increasing doses. Overall, A. tubingensis was less sensitive to treatments than A. steynii. Depending on the species, aw and temperature affected GR and OTA production in a different way. In A. steynii cultures, optimal growth occurred at 0.96 aw and 32 °C while optimal OTA production happened at 0.99 aw and 32 °C. In A. tubingensis cultures optimal growth happened at 0.99 aw and 32 °C, although the best conditions for OTA production were 0.99 aw and 24 °C. Thus, these species can be very competitive in warm climates and storage conditions. The EVOH-CINHO films followed by EVOH-IEG and EVOH-CIT films, designed in this study and applied in vapour phase, can be potent antifungal agents against A. steynii and A. tubingensis and strong inhibitors of OTA biosynthesis in maize grains at very low doses. This is the first study on the impact that interacting environmental conditions and bioactive films containing individual components of EOs have on the growth of these ochratoxigenic fungi and on OTA production in maize grains.

      PubDate: 2018-02-04T21:46:22Z
      DOI: 10.1016/j.ijfoodmicro.2018.02.002
       
  • Multiplex polymerase chain reaction assays for the detection of the
           zearalenone chemotype of Fusarium species in white and brown rice
    • Authors: Jae Ho Sim; Fei Tian; Soo Yeon Jung; Joong-Hyuck Auh; Hyang Sook Chun
      Abstract: Publication date: Available online 3 February 2018
      Source:International Journal of Food Microbiology
      Author(s): Jae Ho Sim, Fei Tian, Soo Yeon Jung, Joong-Hyuck Auh, Hyang Sook Chun
      Early detection of the zearalenone (ZEA) chemotype of Fusarium species could be a precautionary measure for preventing ZEA contamination in rice. In this study, a multiplex polymerase chain reaction (mPCR) assay for detecting ZEA-producing fungi in rice was established using a set of four primers targeting the ZEA biosynthesis genes PKS3, PKS13, ZEB1, and ZEB2. Two mPCR approaches were used: one that amplified the DNA obtained from Fusarium isolates (conventional method) and another that directly amplified the target DNA from rice samples without time-consuming DNA isolation (direct method). The two mPCR methods showed high sensitivity in detecting ZEA-producing species, with a detection limit of 1.25 pg/μL of genomic DNA and 102 and 103 spores/g of white and brown rice, respectively. Both methods were specific for ZEA-producing species and gave four band patterns. The application of the two mPCR methods to 51 Fusarium isolates and 41 rice samples revealed that 31% (16 of 51) and 24% (10 of 41) of the samples were contaminated with ZEA-producing species, respectively. The mPCR results were further evaluated using high-performance liquid chromatography; in general, the two methods yielded similar results. These findings indicate that both mPCR methods are suitable for the detection of ZEA-producing Fusarium species in white and brown rice; however, the direct method yielded more rapid results.

      PubDate: 2018-02-04T21:46:22Z
      DOI: 10.1016/j.ijfoodmicro.2018.02.003
       
  • ICFMH Announcement
    • Abstract: Publication date: 21 February 2018
      Source:International Journal of Food Microbiology, Volume 267


      PubDate: 2018-01-27T09:09:06Z
       
  • Effect of immunomagnetic bead size on recovery of foodborne pathogenic
           bacteria
    • Authors: Jing Chen; Bosoon Park
      Pages: 1 - 8
      Abstract: Publication date: 21 February 2018
      Source:International Journal of Food Microbiology, Volume 267
      Author(s): Jing Chen, Bosoon Park
      Immunomagnetic separation (IMS) as a culture-free enrichment sample preparation technique has gained increasing popularity in the development of rapid detection methods for foodborne pathogens. While the use of magnetic nanoparticles in IMS is on the rise due to substantially larger surface area compared to conventional magnetic microparticles, the effects of immunomagnetic bead (IMB) size on pathogen cell recovery are not fully understood. In this study we used IMBs of different sizes (100, 500, and 1000nm diameters) to capture Salmonella Enteritidis, a common foodborne pathogen, from buffer solutions as well as food matrices (chicken carcass rinse and liquid egg white). The IMS recovery and non-specific binding rate were compared. The recoveries of Salmonella cells in buffers was highest using the 100nm IMBs (88–96%), followed by the 500nm (31–89%) and 1000nm (4.1–61%) IMBs, demonstrating a significant size effect. The non-specific binding rates of E. coli also increased as IMB size decreased. A 2–72% reduction in Salmonella recovery was observed in chicken carcass rinse and liquid egg white samples compared to in buffers, and this reduction was more significant using 500 and 1000nm IMBs. However, lower IMS recoveries (10–56%) was found in 100nm IMBs two months after preparation. Overall, magnetic nanoparticles yielded superior IMS efficiency to micrometer size IMBs and were less subjective to interference from food matrices. Nevertheless, their long term stability remains an obstacle towards successful use in IMS.

      PubDate: 2017-12-24T09:19:46Z
      DOI: 10.1016/j.ijfoodmicro.2017.11.022
      Issue No: Vol. 267 (2017)
       
  • Dynamics of biofilm formation by Listeria monocytogenes on stainless steel
           under mono-species and mixed-culture simulated fish processing conditions
           and chemical disinfection challenges
    • Authors: Eleni Papaioannou; Efstathios D. Giaouris; Panagiotis Berillis; Ioannis S. Boziaris
      Pages: 9 - 19
      Abstract: Publication date: 21 February 2018
      Source:International Journal of Food Microbiology, Volume 267
      Author(s): Eleni Papaioannou, Efstathios D. Giaouris, Panagiotis Berillis, Ioannis S. Boziaris
      The progressive ability of a six-strains L. monocytogenes cocktail to form biofilm on stainless steel (SS), under fish-processing simulated conditions, was investigated, together with the biocide tolerance of the developed sessile communities. To do this, the pathogenic bacteria were left to form biofilms on SS coupons incubated at 15°C, for up to 240h, in periodically renewable model fish juice substrate, prepared by aquatic extraction of sea bream flesh, under both mono-species and mixed-culture conditions. In the latter case, L. monocytogenes cells were left to produce biofilms together with either a five-strains cocktail of four Pseudomonas species (fragi, savastanoi, putida and fluorescens), or whole fish indigenous microflora. The biofilm populations of L. monocytogenes, Pseudomonas spp., Enterobacteriaceae, H2S producing and aerobic plate count (APC) bacteria, both before and after disinfection, were enumerated by selective agar plating, following their removal from surfaces through bead vortexing. Scanning electron microscopy was also applied to monitor biofilm formation dynamics and anti-biofilm biocidal actions. Results revealed the clear dominance of Pseudomonas spp. bacteria in all the mixed-culture sessile communities throughout the whole incubation period, with the in parallel sole presence of L. monocytogenes cells to further increase (ca. 10-fold) their sessile growth. With respect to L. monocytogenes and under mono-species conditions, its maximum biofilm population (ca. 6logCFU/cm2) was reached at 192h of incubation, whereas when solely Pseudomonas spp. cells were also present, its biofilm formation was either slightly hindered or favored, depending on the incubation day. However, when all the fish indigenous microflora was present, biofilm formation by the pathogen was greatly hampered and never exceeded 3logCFU/cm2, while under the same conditions, APC biofilm counts had already surpassed 7logCFU/cm2 by the end of the first 96h of incubation. All here tested disinfection treatments, composed of two common food industry biocides gradually applied for 15 to 30min, were insufficient against L. monocytogenes mono-species biofilm communities, with the resistance of the latter to significantly increase from the 3rd to 7th day of incubation. However, all these treatments resulted in no detectable L. monocytogenes cells upon their application against the mixed-culture sessile communities also containing the fish indigenous microflora, something probably associated with the low attached population level of these pathogenic cells before disinfection (<102 CFU/cm2) under such mixed-culture conditions. Taken together, all these results expand our knowledge on both the population dynamics and resistance of L. monocytogenes biofilm cells under conditions resembling those encountered within the seafood industry and should be considered upon designing and applying effective anti-biofilm strategies.

      PubDate: 2017-12-24T09:19:46Z
      DOI: 10.1016/j.ijfoodmicro.2017.12.020
      Issue No: Vol. 267 (2017)
       
  • 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)
       
  • Seasonal variances in bacterial microbiota and volatile organic compounds
           in raw milk
    • Authors: Beata Nalepa; Magdalena Anna Olszewska; Lidia Markiewicz
      Abstract: Publication date: Available online 24 December 2017
      Source:International Journal of Food Microbiology
      Author(s): Beata Nalepa, Magdalena Anna Olszewska, Lidia Markiewicz


      PubDate: 2017-12-24T09:19:46Z
      DOI: 10.1016/j.ijfoodmicro.2017.12.024
       
  • Effect of pomegranate based marinades on the microbiological, chemical and
           sensory quality of chicken meat: A metabolomics approach
    • Authors: Anastasia E. Lytou; George-John E. Nychas; Efstathios Z. Panagou
      Abstract: Publication date: Available online 21 December 2017
      Source:International Journal of Food Microbiology
      Author(s): Anastasia E. Lytou, George-John E. Nychas, Efstathios Z. Panagou
      Pomegranate juice is a product with enhanced functional properties that could be used as an alternative to traditional marination ingredients and effectively retard microbial growth along with providing an improved sensory result. In this study, two pomegranate based marinades were prepared for the marination of chicken breast fillets and the marinated samples were aerobically stored at 4 and 10°C for 9days. Raw, non-marinated chicken samples were used as control. Levels of total viable counts (TVC), Pseudomonas spp., Brochothrix thermosphacta, Enterobacteriaceae and lactic acid bacteria (LAB) were determined together with sensory assessment to evaluate the evolution of spoilage. The profile of organic acids and volatile compounds was also analyzed during storage. The shelf life of marinated samples was significantly extended compared to control samples at both storage temperatures (e.g., up to 5 and 6days for the pomegranate/lemon marinated samples stored at 4 and 10°C, respectively) as evaluated by both microbiological and sensory analyses. The profile of the organic acids and the volatilome of marinated and control samples were remarkably differentiated according to storage time, microbial load and sensory score. The findings of this study suggest that pomegranate juice could be used as a novel ingredient in marinades to improve the sensory attributes, while prolonging the shelf life of chicken meat.

      PubDate: 2017-12-24T09:19:46Z
      DOI: 10.1016/j.ijfoodmicro.2017.12.023
       
  • Distribution of anisakid nematodes parasitizing rajiform skates under
           commercial exploitation in the Southwestern Atlantic
    • Authors: Irigoitia Manuel Marcial; Braicovich Paola Elizabeth; Lanfranchi Ana Laura; Farber Marisa Diana; Timi Juan Tomás
      Abstract: Publication date: Available online 19 December 2017
      Source:International Journal of Food Microbiology
      Author(s): Irigoitia Manuel Marcial, Braicovich Paola Elizabeth, Lanfranchi Ana Laura, Farber Marisa Diana, Timi Juan Tomás
      In order to evaluate the infestation by anisakids present in elasmobranchs and their distribution in the Argentine Sea, this study was carried at a regional scale with the following aims: 1) to identify those anisakid species present in skates under exploitation; 2) to characterize quantitatively these infestations and 3) to determine those factors driving the variability in parasite burdens across skate species. A total of 351 skates, belonging to 3 species (218 Sympterygia bonapartii, 86 Zearaja chilensis and 47 Atlantoraja castelnaui) and from different localities of the Argentine Sea were examined for anisakids. Parasites were found in the stomach wall at high prevalence in some samples. Based on morphology and mtDNA cox2 sequences analyses (from 24 larval worms), specimens were identified as Anisakis berlandi, A. pegreffii and Pseudoterranova cattani; the last two known as potentially pathogenic for humans. Differential distribution patterns were observed across parasite and hosts species. In general, fish caught in southern and deeper waters exhibited higher loads of Anisakis spp., whereas infestation levels by P. cattani increase in larger skates. Taking into account that the mere presence of worms or their antigens in fish meat can provoke allergic responses, information on distribution of parasites and their variability is essential for the implementation of food safety practices.

      PubDate: 2017-12-24T09:19:46Z
      DOI: 10.1016/j.ijfoodmicro.2017.12.009
       
 
 
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