Biology subjects

Khan, M. S. R.

Publications and source records attributed to Khan, M. S. R..

3 recordsLinked to original sources

bioRxiv2022

Genomic diversity of Streptococcus uberis isolated from clinical mastitis of cattle in selected areas of Bangladesh

Streptococci are the major etiology in mastitis, a cause of huge economic losses in the dairy industries. Streptococcus (S.) agalactiae, S. dysagalactiae and S. uberis are mostly encountered in bovine mastitis; however, data on the diversity and characteristics of Streptococcus in clinical mastitis of cattle in Bangladesh is lacking. Thus, the present study was aimed to determine the diversity and antimicrobial resistance pattern of Streptococcus spp. isolated from clinical mastitis of cattle reared in Bangladesh. A total of 105 milk samples comprising eighty (80) from cattle with clinical mastitis (CCM) and twenty-five (25) from apparently healthy cattle (AHC) in four prominent dairy farms and one dairy community were purposively collected and examined in this study. Milk samples were enriched in Luria Bertani broth (LB) and Streptococcus spp. was isolated on Modified Edwards Medium and identified by 16S rRNA gene sequencing. Among eighty (80) clinical samples, eighteen (18) were positive for Streptococcus spp. while none of the milk from AHC revealed Streptococcus by cultural and molecular examination. Sequencing and phylogenetic analysis identified 55.6%, 33.3%, 5.6% and 5.6% of the Streptococcus isolates as S. uberis, S. agalactiae, S. hyovaginalis and S. urinalis, respectively. Antibiotic sensitivity testing with antimicrobials commonly used to treat clinical mastitis revealed 100%, 100%, and 30% of the S. agalactiae, S. hyovaginalis, and S. uberis as multidrug-resistant, respectively. Molecular characterization through whole genome sequencing of five (5) S. uberis isolates identified at least two novel ST types of S. uberis circulating in the study areas with one ST (4/5 isolates) clustered with the isolates from China, India and Thailand, and the other (1/5) with UK, Ireland and Australia. Pan-genome analysis and phylogeny of the core genome sequences also clustered the isolates into two sub-clusters, indicating the presence of at least two different subtypes of S. uberis in the study area. On virulence profiling, all the isolates of this study were found to harbor at least 35 virulence and putative virulence genes probably associated with intramammary infection (IMI) indicating all the S. uberis isolated in this study as potential pathogen. From the overall findings it was evident that Strepococcus occurring in bovine mastitis are diverse and S. uberis genome carries an array of putative virulence factors which need to be investigated genotypically and phenotypically to identify a specific trait or determinant governing the virulence and fitness of this bacterium. Moreover, Streptococcus isolated in this study carried multidrug resistance which needs careful consideration during the selection of a treatment regimen for mastitis.

microbiology↗

bioRxiv2022

metGWAS 1.0: An R workflow for network-driven over-representation analysis between independent metabolomic and meta-genome wide association studies

BackgroundMany diseases may result from disrupted metabolic regulation. Metabolite-GWAS studies assess the association of polymorphic variants with metabolite levels in body fluids. While these studies are successful, they have a high cost and technical expertise burden due to combining the analytical biochemistry of metabolomics with the computational genetics of GWAS. Currently, there are 100s of standalone metabolomics and GWAS studies related to similar diseases or phenotypes. A method that could statically evaluate these independent studies to find novel metabolites-genes association is of high interest. Although such an analysis is limited to genes with known metabolite interactions due to the unpaired nature of the data sets, any discovered associations may represent biomarkers and druggable targets for treatment and prevention. MethodsWe developed a bioinformatics tool, metGWAS 1.0, that generates and statistically compares metabolic and genomic gene sets using a hypergeometric test. Metabolic gene sets are generated by mapping disease-associated metabolites to interacting proteins (genes) via online databases. Genomic gene sets are identified from a network representation of the GWAS Catalog comprising 100s of studies. ResultsThe metGWAS 1.0 tool was evaluated using standalone metabolomics datasets extracted from two metabolomics-GWAS case studies. In case-study 1, a cardiovascular disease association study, we identified nine genes (APOA5, PLA2G5, PLA2G2D, PLA2G2E, PLA2G2F, LRAT, PLA2G2A, PLB1, and PLA2G7) that interact with metabolites in the KEGG glycerophospholipid metabolism pathway and contain polymorphic variants associated with cardiovascular disease (P < 0.005). The gene APOA5 was matched from the original metabolomics-GWAS study. In case study 2, a urine metabolome study of kidney metabolism in healthy subjects, we found marginal significance (P = 0.10 and P = 0.13) for glycine, serine, and threonine metabolism and alanine, aspartate, and glutamate metabolism pathways to GWAS data relating to kidney disease. ConclusionThe metGWAS 1.0 platform provides insight into developing methods that bridge standalone metabolomics and disease and phenotype GWAS data. We show the potential to reproduce findings of paired metabolomics-GWAS data and provide novel associations of gene variation and metabolite expression.

bioinformatics↗

bioRxiv2021

Virulence and antimicrobial resistance profile of non-typhoidal Salmonella enterica serovars recovered from poultry processing environments at wet markets in Dhaka, Bangladesh

The rapid emergence of virulent and multidrug-resistant (MDR) non-typhoidal Salmonella (NTS) enterica serovars are a growing public health concern globally. The present study focused on the assessment of the pathogenicity and antimicrobial resistance (AMR) profiling of NTS enterica serovars isolated from chicken processing environments at wet markets in Dhaka, Bangladesh. A total number of 870 samples consisting of carcass dressing water (CDW), chopping board swabs (CBS), and knife swabs (KS) were collected from 29 wet markets. The prevalence of Salmonella was found to be 20% in CDW, 19.31% in CBS and 17.58% in KS, respectively. Meanwhile, the MDR Salmonella was found to be 72.41%, 73.21% and 68.62% in CDW, CBS, and KS, respectively. All isolates were screened by polymerase chain reaction (PCR) for eight virulence genes, namely invA, agfA, IpfA, hilA, sivH, sefA, sopE, and spvC. The S. Enteritidis and untyped Salmonella isolate harbored all virulence genes while S. Typhimurium isolates carried six virulence genes except sefA and spvC. Phenotypic resistance revealed decreased susceptibility to ciprofloxacin, streptomycin, ampicillin, tetracycline, gentamycin, sulfamethoxazole-trimethoprim, amoxicillin-clavulanic acid and azithromycin. Genotypic resistance showed higher prevalence of plasmid mediated blaTEM followed by tetA, sul1, sul2, sul3, and strA/B genes. Harmonic and symmetrical trend was observed among the phenotypic and genotypic resistance patterns of the isolates. The research findings anticipate that MDR and virulent NTS enterica serovars are prevailing in the wet market environments which can easily enter into the human food chain. There was a resilient and significant correlation existent among the phenotypic and genotypic resistance patterns and virulence genes of Salmonella isolate recovered from carcass dressing water, chopping board swabs, and knife swabs (p < 0.05), respectively.

microbiology↗