Extreme flooding is one of the major risk factors for human health, and it can significantly influence the microbial communities and enhance the mobility of infectious disease agents within the affected areas. The flood crisis in 2018 was one of the severe natural calamities recorded in the southern state of India (Kerala) that significantly affected its economy and ecological habitat. We utilized a combination of shotgun metagenomics and bioinformatics approaches to understand the bacterial profile and the abundance of pathogenic and antibiotic-resistant bacteria in extremely flooded areas of Kuttanad, Kerala (4–10 feet below sea level). Here we report the bacterial profiles of flooded sites that are abundant with virulent and resistant bacteria. The flooded sites were heavily contaminated with faecal contamination indicators such as Escherichia coli and Enterococcus faecalis and multidrug-resistant strains of Pseudomonas aeruginosa, Salmonella typhi/typhimurium, Klebsiella pneumoniae, Vibrio cholerae. The resistome of the flooded sites contains 103 known resistant genes, of which 38% are plasmid-encoded, where most of them are known to be associated with pathogenic bacteria. Our results reveal an overall picture of the bacterial profile and resistome of sites following a devastating flood event, which might increase the levels of pathogens and its associated risks.

Adipocytes are key players in maintaining energy homeostasis and are classified into two different categories: white and brown adipocytes. While white adipocytes store energy as triacylglycerols in lipid droplets, brown adipocytes combust excess chemical energy and release in the form of heat through uncoupled respiration. This characteristic phenomenon of brown fat attracts researchers and pharmacological industries to view brown fat as one of the potential therapeutic targets for obesity and associated metabolic disease. In the current study, we investigated the effect of a small molecule, sesaminol (SML) on brown fat activity and found that SML induces the thermogenic program in primary white adipocytes as well as chow diet fed mice. In particular, SML treatment to mice elevated mitochondrial complex proteins and the rate of oxygen consumption in brown and white fat. Administration of SML to high fat diet (HFD) challenged mice decreased weight gain, adiposity and cholesterol levels along with an increase of brown fat gene program in brown and white fat. Mechanistically, SML repressed the myogenic gene program in C2C12 myoblasts and increased all mitochondrial marker genes as appeared in brown adipose cells. Together, our results demonstrate that SML stimulates brown adipose function and protects mice against diet‐induced weight gain.

Extreme flooding is one of the major risk factors for human health, and it can significantly influence the microbial communities and enhance the mobility of infectious disease agents within its affected areas. The flood crisis in 2018 was one of the severe natural calamities recorded in the southern state of India (Kerala) that significantly affected its economy and ecological habitat. We utilized a combination of shotgun metagenomics and bioinformatics approaches for understanding microbiome disruption and the dissemination of pathogenic and antibiotic-resistant bacteria on flooded sites. Here we report, altered bacterial profiles at the flooded sites having 77 significantly different bacterial genera in comparison with non-flooded mangrove settings. The flooded regions were heavily contaminated with faecal contamination indicators such as Escherichia coli and Enterococcus faecalis and resistant strains of Pseudomonas aeruginosa, Salmonella Typhi/Typhimurium, Klebsiella pneumoniae, Vibrio cholerae and Staphylococcus aureus. The resistome of the flooded sites contains 103 resistant genes, of which 38% are encoded in plasmids, where most of them are associated with pathogens. The presence of 6 pathogenic bacteria and its susceptibility to multiple antibiotics including ampicillin, chloramphenicol, kanamycin and tetracycline hydrochloride were confirmed in flooded and post-flooded sites using traditional culture-based analysis followed by 2 16S rRNA sequencing. Our results reveal altered bacterial profile following a devastating flood event with elevated levels of both faecal contamination indicators and resistant strains of pathogenic bacteria. The circulation of raw sewage from waste treatment settings and urban area might facilitate the spreading of pathogenic bacteria and resistant genes.

Background Quantitative determination of neutralizing antibodies against Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2) is paramount in immunodiagnostics, vaccine efficacy testing, and immune response profiling among the vaccinated population. Cost-effective, rapid, easy-to-perform assays are essential to support the vaccine development process and immunosurveillance studies. Methods We describe a bead-based screening assay for S1-neutralization using recombinant fluorescent proteins of hACE2 and SARS-CoV2-S1, immobilized on solid beads employing nanobodies/metal-affinity tags. Nanobody-mediated capture of SARS-CoV-2-Spike (S1) on agarose beads served as the trap for soluble recombinant ACE2-GFPSpark, inhibited by neutralizing antibody. Results The first approach demonstrates single-color fluorescent imaging of ACE2 –GFPSpark binding to His-tagged S1-Receptor Binding Domain (RBD-His) immobilized beads. The second approach is dual-color imaging of soluble ACE2-GFPSpark to S1-Orange Fluorescent Protein (S1-OFPSpark) beads. Both methods showed a good correlation with the gold standard pseudovirion assay and can be adapted to any fluorescent platforms for screening. Life-time imaging of the ACE2-GFPSpark confirmed the interaction of ACE2 and S1-OFPSpark on beads. Conclusions The self-renewable source of secreted recombinant proteins from stable cells and its direct use without necessitating purification renders the platform a cost-effective and rapid one than the popular pseudovirion assay and live virus-based assays. Any laboratory with minimum expertise can rapidly perform this bead assay for neutralizing antibody detection using stable engineered cells. Statement of significance The bead-based assay platform for screening neutralizing antibodies against SARS CoV-2 is a cost-effective alternative for the gold standard pseudovirion assay. This assay will accelerate our efforts to develop newer vaccines against COVID-19 and can be used to discover viral entry blockers engaging S1-ACE2 in drug screening settings.

Background The environmental microbiome has a direct influence on human health and disease. Previous reports suggest that urbanization and anthropogenic activities can alter natural microbial flora and potentially spread infectious disease-causing agents by emergence of pathogenic strains of bacteria. The nature of microbes present in urban settings and the flow of genetic elements between environmental and clinically relevant pathogenic bacteria, however, remains largely unknown. Results To unravel the bacterial diversity and resistome profile of multiple hotspot setups of a tropical urban system such as transport hubs, wet markets, hospital surroundings, waste dumps, and urban coastal area (beaches) metagenomics analyses of sediment samples from around Thiruvananthapuram city were done. Our study revealed the presence of 3,735 species belonging to 46 phyla of bacteria and archaea. The phylum Pseudomonadota was the most abundant bacterial community, followed by Bacteriodota and Actinomycetota. The genus Cloacibacterium had the highest overall relative abundance, while Pseudomonas was the most prevalent bacterial genus in hospital surroundings and coastal area (beaches) settings. We identified 291 antimicrobial resistance genes (ARGs) in the urban resistome, conferring resistance to more than 15 drug classes. The hospital settings had the highest number of ARGs across different drug classes. From the culturomics microcosm setups, we reconstructed 62 high-quality metagenome-assembled genomes (MAGs) which shows high resemblance to pathogenic bacterias such as Klebsiella pneumoniae, Escherichia coli and Acinetobacter baumannii etc. The ARGs detected in these genomes include genes encoding antibiotic-modifying enzymes (ArnT, eptA, eptB), beta-lactamase (ampC, ampC1, ampH), transcription regulating proteins (KpnE, KpnF, KpnG), efflux pumps (oqxA, oqxB). Furthermore, eight MAGS belonging to Acinetobacter kookii, Acinetobacter pitti, Acinetobacter baumannii, Acinetobacter gerneri, Escherichia coli, Klebsiella pneumoniae and Klebsiella quasipneumoniae were found to contain virulence factors such as siderophores (acinetobactin, aerobactin, enterobactin etc.), capsule, secretion systems belonging to type III group) (T3SS, TTSS etc) or type II (T2SS), fimbriae (type 3 and I), efflux pump (AdeFGH), or quorum sensing (abaR) associated with pathogenicity. Conclusions The study provides insights into bacterial composition, antimicrobial resistance, and virulence potential in urban environments, highlighting the importance of monitoring and managing antimicrobial resistance in urban ecosystems.