Focused Review:Insight and Updates on COVID-19 from Progress in Microbes and Molecular Biology

COVID-19 Bulletins from various countries have been published as the pandemic hit. This focused review provides an overview of the published COVID-19 cases, including the first case detected in respective countries, preventive measures implemented, and vaccinations available for some countries, depending on the time it was written. The countries that will be covered in this review are the United Kingdom, Spain, Malaysia, Singapore, Thailand, India, Australia, South Africa, and Brunei. This review also discusses the variants of concern (VOCs) that emerged since the start of the pandemic, which include variants: Alpha (B.1.1.7), Beta (B.1.351), Delta (B.1.617.2), Gamma (P.1), and Omicron (B.1.1.529). COVID-19-associated gastrointestinal manifestations and mental health implications and the application of probiotics as a potential adjunct therapy to psychotropic medications will be addressed in this review. Additional information on COVID-19 will also be reviewed, such as risk factors affecting COVID-19 case fatality rate, positive impacts of public health measures, the cost-effectiveness of public health strategies on COVID-19 control, and the COVID-19 pandemic and diet.</p

An insight into the isolation, enumeration and molecular detection of Listeria monocytogenes in food

Listeria monocytogenes, a foodborne pathogen that can cause listeriosis through the consumption of food contaminated with this pathogen. The ability of L. monocytogenes to survive in extreme conditions and cause food contaminations have become a major concern. Hence, routine microbiological food testing is necessary to prevent food contamination and outbreaks of foodborne illness. This review provides insight into the methods for cultural detection, enumeration and molecular identification of L. monocytogenes in various food samples. There are a number of enrichment and plating media that can be used for the isolation of L. monocytogenes from food samples. Enrichment media such as buffered Listeria Enrichment Broth (BLEB), Fraser broth and University of Vermont Medium (UVM) Listeria enrichment broth are recommended by regulatory agencies such as FDA-BAM, USDA-FSIS and ISO. Many plating media are available for the isolation of L. monocytogenes, for instance, PALCAM, Oxford and other chromogenic media. Besides, reference methods like FDA-BAM, ISO 11290 method and USDA-FSIS method are usually applied for the cultural detection or enumeration of L. monocytogenes. MPN technique is applied for the enumeration of L. monocytogenes in the case of low level contamination. Molecular methods including polymerase chain reaction (PCR), multiplex polymerase chain reaction (mPCR), real-time/quantitative polymerase chain reaction (qPCR), nucleic acid sequence-based amplification (NASBA), loop-mediated isothermal amplification (LAMP), DNA microarray and Next Generation Sequencing (NGS) technology for the detection and identification of L. monocytogenes are discussed in this review. Overall, molecular methods are rapid, sensitive, specific, time- and labour-saving. In future, there are chances for the development of new techniques for the detection and identification of foodborne with improved features