Gut microbiome composition reveals the distinctiveness between the Bengali people and the Indigenous ethnicities in Bangladesh.

Ethnicity has a significant role in shaping the composition of the gut microbiome, which has implications in human physiology. This study intends to investigate the gut microbiome of Bengali people as well as several indigenous ethnicities (Chakma, Marma, Khyang, and Tripura) residing in the Chittagong Hill Tracts areas of Bangladesh. Following fecal sample collection from each population, part of the bacterial 16 s rRNA gene was amplified and sequenced using Illumina NovaSeq platform. Our findings indicated that Bangladeshi gut microbiota have a distinct diversity profile when compared to other countries. We also found out that Bangladeshi indigenous communities had a higher Firmicutes to Bacteroidetes ratio than the Bengali population. The investigation revealed an unclassified bacterium that was differentially abundant in Bengali samples while the genus Alistipes was found to be prevalent in Chakma samples. Further research on these bacteria might help understand diseases associated with these populations. Also, the current small sample-sized pilot study hindered the comprehensive understanding of the gut microbial diversity of the Bangladeshi population and its potential health implications. However, our study will help establish a basic understanding of the gut microbiome of the Bangladeshi population.

Clinical features and outcomes of COVID-19 patients with concomitant herpesvirus co-infection or reactivation: A systematic review.

Background: Since the first case of COVID-19 was diagnosed in Wuhan, China in late 2019, concomitant infections with Herpesviridae were documented that were presented from simple skin manifestations to severe life-threatening conditions that may lead to mortality. In this systematic review, we have included studies conducted in different parts of the world to find out the association of clinical features and outcomes of COVID-19 infection and concomitant Herpesviridae infection. Methods: A comprehensive search was conducted in electronic databases including Medline through PubMed, Cochrane database, Scopus and Web of science (core collection). Two review authors independently screened the articles and extracted data. The Risk of bias assessment was done by using RoBANS tool. Results: A total of 919 studies were retrieved and 19 studies were included having data of 539 patients who were infected with both COVID-19 and Herpesviridae. Herpes Simplex-1, Varicella Zoster, Cytomegalovirus, Epstein-Barr virus and Human Herpes Virus-6 were the detected viruses in the included studies. Cytomegalovirus (CMV) reactivation was the most detected concomitant infection. In case of reactivation with more than one Herpes virus mortality among patients were detected along with single viral infection in some studies. Significant association was noted in dosage and usage of steroid and Herpesviridae reactivation in COVID-19 patients. Blood markers such as D-dimer, CRP along with length of stay in the ICU and usage of invasive mechanical ventilation were found to be the significantly associated markers. Conclusion: Findings from this study will aid clinicians to assess and treat COVID-19 cases with co-infections.

Association of HLA gene polymorphism with susceptibility, severity, and mortality of COVID-19: A systematic review.

HLA is crucial for appropriate immune responses in several viral infections, as well as in severe acute respiratory syndrome coronavirus-2 (SARS CoV-2). The unpredictable nature of Coronavirus Disease 19 (COVID-19), observed in both inter-individual and inter-population level, raises the question, to what extent the HLA, as part of host genetic factors, contribute to disease susceptibility and prognosis. We aimed to identify significant HLAs, those were investigated till now, for their association with COVID-19. Three databases were searched (PubMed, Cochrane library, and Web of Science) and articles published between January 2020 and May 2021 were included for in-depth analysis. Two separate teams including four observers independently extracted the summary data, with discrepancies resolved by consensus. This study is registered with PROSPERO (CRD42021251670). Of 1278 studies identified, 36 articles were included consisting of 794,571 participants. Countries from the European region appeared in the highest number of studies and vice versa for countries from South East Asia. Among 117 significantly altered alleles, 85 (72.65%) were found to have a positive correlation with COVID-19 and 33 (27.35%) alleles were observed having a negative correlation. HLA A*02 is the most investigated allele (n = 18) and showed contradictory results. Non-classical HLA E was explored by only one study and it showed that E*01:01 is associated with severity. Both in silico and wet lab data were considered and contrasting results were found from two approaches. Although several HLAs depicted significant association, nothing conclusive could be drawn because of heterogeneity in study designs, HLA typing methods, and so forth. This systematic review shows that, though HLAs play role in COVID-19 susceptibility, severity, and mortality, more uniformly designed, interrelated studies with the inclusion of global data, for use in evidence-based medicine are needed.