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- Options appraisal of various β‒D‒glucan assay systems for
a diagnostic microbiology laboratory
Authors: Shazia Parveen, Sanjay Bhattacharya
Pages: 1 - 7
Abstract: Shazia Parveen, Sanjay Bhattacharya
Journal of The Academy of Clinical Microbiologists 2023 25(1):1-7
Invasive fungal infections (IFIs) have become a substantial concern in immunocompromised cancer patients, diabetics, hematopoietic stem cell transplant and solid organ transplant recipients with significant morbidity and mortality, Amongst IFIs, Candida and Aspergillus continue to be the most frequently reported, along with Fusarium and Zygomycetes. The need for tissue samples and the time required for cultures and histological investigation has made diagnosing IFIs problematic in the past. The detection of IFIs non-invasively by measuring biological markers such as the galactomannan antigen and the fungal wall component (1-3)-β-D-Glucan (BDG) have emerged as excellent options. In view of multiple kits available for detection and quantification of the fungal wall component (1-3)-BDG, it becomes essential to perform the options appraisal to find out the best available test option for a microbiology laboratory. Our work focuses on comparing various (1-3)-BDG detection systems available in the market.
Citation: Journal of The Academy of Clinical Microbiologists 2023 25(1):1-7
PubDate: Thu,1 Jun 2023
DOI: 10.4103/jacm.jacm_28_22
Issue No: Vol. 25, No. 1 (2023)
- Option appraisal of matrix-assisted laser desorption ionisation time of
flight systems for a diagnostic microbiology laboratory
Authors: Anish Pyne, Sanjay Bhattacharya
Pages: 8 - 15
Abstract: Anish Pyne, Sanjay Bhattacharya
Journal of The Academy of Clinical Microbiologists 2023 25(1):8-15
A major challenge for a clinical diagnostic bacteriology/mycology laboratory is to identify the causal microorganism to the species level within a limited time frame. Conventional microbiological techniques such as culture, Gram stain, biochemical tests and molecular tests like 16S rRNA analysis can take days to yield the desired result. Matrix-assisted laser desorption ionisation-time of flight (MALDI-TOF) mass spectrometry (MS) system serves as a potential solution as it can provide accurate identification results within minutes. While several MALDI-TOF MS instruments are in the market, choosing the right system and comparing all the relative pros and cons can be difficult. Our present study focuses on this aspect as we have performed an option appraisal between two leading MALDI-TOF MS instruments, namely the MBT Sirius IVD system (Bruker) and the VITEK-MS system (Biomerieux). We have discussed all the parts of MALDI-TOF systems in detail followed by a cost analysis categorising the total cost into capital and consumable cost which will provide clarity of the estimated budget. We have also discussed the principle involved in organism identification and have compared the two systems concerning technology, accuracy, database, optimal operating conditions, etc. This article aims to provide readers with a better understanding of MALDI-TOF systems and facilitate informed decision-making regarding the acquisition of such systems.
Citation: Journal of The Academy of Clinical Microbiologists 2023 25(1):8-15
PubDate: Thu,1 Jun 2023
DOI: 10.4103/jacm.jacm_4_23
Issue No: Vol. 25, No. 1 (2023)
- Diagnostic and quantitative performance of the GeneXpert Mycobacterium
tuberculosis/resistance to rifampin assay on pulmonary and extrapulmonary
tuberculosis samples
Authors: Tummidi Santosh, Prashant Sood, Ashok Rattan, Deepa Dave, Nagiredla Puneeta
Pages: 16 - 23
Abstract: Tummidi Santosh, Prashant Sood, Ashok Rattan, Deepa Dave, Nagiredla Puneeta
Journal of The Academy of Clinical Microbiologists 2023 25(1):16-23
INTRODUCTION: No study has simultaneously assessed the diagnostic and quantitative performance of the GeneXpert Mycobacterium tuberculosis/resistance to rifampicin (MTB/RIF) assay on pulmonary and extrapulmonary samples processed in an Indian laboratory. We examined this to assess if GeneXpert can complement existing diagnostic facilities.METHODS: The performance of GeneXpert and acid-fast microscopy were evaluated against culture in 455 pulmonary and 69 extrapulmonary specimens. Their sensitivity, specificity, predictive values and area under the curve (AUC) were estimated. GeneXpert cycle threshold (Ct) cut-offs were also computed to assess their utility in predicting smear positivity and time to culture positivity (TTCP).RESULTS: GeneXpert was significantly more sensitive (100% vs. 84.4%; P < 0.001) and nearly as specific (94.8% vs. 96.7%; P = 0.344), with a greater AUC (0.97 vs. 0.91; P = 0.002) than acid-fast microscopy. It was sensitive and specific for pulmonary (100%; 94.1%) and extrapulmonary (100%; 96.5%) samples, and 100% sensitive for sputum, bronchoalveolar lavage (BAL), lymph node aspirates, pleural fluid, pus and urine. It detected smear-negative specimens with 100% sensitivity. GeneXpert Ct was inversely correlated with sputum smear grading (ρ = −0.66) and positively with TTCP (ρ =0.70). Mean Ct cut-offs of 21.4, 20.1 and 24.6 predicted smear positivity with maximum sensitivity and specificity in sputum, BAL and extrapulmonary samples, respectively. Rifampicin resistance was seen in 17% of samples.CONCLUSIONS: GeneXpert can be a reliable first-line diagnostic for both pulmonary and extrapulmonary samples. It can effectively detect smear-negative and paucibacillary patients, and estimate smear positivity and bacillary burden. This can help Indian laboratories to detect cases early and interrupt community transmission.
Citation: Journal of The Academy of Clinical Microbiologists 2023 25(1):16-23
PubDate: Thu,1 Jun 2023
DOI: 10.4103/jacm.jacm_3_23
Issue No: Vol. 25, No. 1 (2023)
- Changing trend in the clinico- bacteriological profile of diabetic foot
infection over a decade: observations from a tertiary care hospital of
India
Authors: Michael L J Pais, Reshmina Chandni Clara D'Souza, Vidya Rao Surlu, Rekha Boloor, Manjeshwar Shrinath Baliga, Ramakrishna Pai Jakribettu
Pages: 24 - 28
Abstract: Michael L J Pais, Reshmina Chandni Clara D'Souza, Vidya Rao Surlu, Rekha Boloor, Manjeshwar Shrinath Baliga, Ramakrishna Pai Jakribettu
Journal of The Academy of Clinical Microbiologists 2023 25(1):24-28
BACKGROUND: Diabetic foot infection (DFI) is a major challenge in podiatric surgery. Initiation of an appropriate antimicrobial drug is the determining factor in the prognosis in DFI.AIM: This study was undertaken to analyse the changing trends in the clinical profile of patients and the bacterial profile causing DFI for over a decade.MATERIALS AND METHODS: This was a retrospective observational study conducted at the department of microbiology and surgery of the tertiary teaching hospital. The clinical and bacterial profile of patients with DFI in 2009 and 2019 was collected and analysed for the changing trend.RESULTS: Amongst the 203 patients (95 in 2009 and 108 in 2019) included in the study, 113 (56%) were male patients. There was a shift in the age group of patients from 51–60 to 61–70 years over a decade. There was a change of most common pathogens from Pseudomonas aeruginosa to Klebsiella species. The resistance rates to third-generation cephalosporins decreased amongst the Gram-negative isolates such as P. aeruginosa and Escherichia coli, but an increase in resistance to carbapenems was observed during the study period. There was reduced incidence of infection with methicillin-resistant Staphylococcus aureus during the study period.CONCLUSION: There was a change in the demographic and bacteriological flora in the DFI patients over a decade. The antimicrobial resistance rate varied for various antimicrobial agents over a decade for a particular pathogen. Regular surveillance of the change in resistance pattern amongst the pathogens is essential for the initiation of appropriate empirical therapy to reduce the morbidity in DFI.
Citation: Journal of The Academy of Clinical Microbiologists 2023 25(1):24-28
PubDate: Thu,1 Jun 2023
DOI: 10.4103/jacm.jacm_27_22
Issue No: Vol. 25, No. 1 (2023)
- Reason for medical devices recall in a hospital: An observation from a
central sterile supply department at a cancer centre in eastern India
Authors: Sujit Roy, Jayanto Dutta, Sarup Khatua, Debabrata Basu
Pages: 29 - 31
Abstract: Sujit Roy, Jayanto Dutta, Sarup Khatua, Debabrata Basu
Journal of The Academy of Clinical Microbiologists 2023 25(1):29-31
Recall of medical devices is a very common phenomenon in every hospital due to several issues. A recall is an action taken on a medical device that violates standard procedure. This action is necessary when a device is found defective or a risk to health. It may happen by manual or mechanical error but ultimately a negative phenomenon that needs to control for unnecessary costs and save resources. A policy should be developed for recalling the items. Whenever the sterility of any product seems doubtful, the infection control committee and the quality team should be informed so that follow-up surveillance of patients can be conducted.
Citation: Journal of The Academy of Clinical Microbiologists 2023 25(1):29-31
PubDate: Thu,1 Jun 2023
DOI: 10.4103/jacm.jacm_5_23
Issue No: Vol. 25, No. 1 (2023)
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