Samad, M. A. | bioRxiv Science

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↗

bioRxiv2019

BR-bodies provide selectively permeable condensates that stimulate mRNA decay and prevent release of decay intermediates

Biomolecular condensates play a key role in organizing RNAs and proteins into membraneless organelles. Bacterial RNP-bodies (BR-bodies) are a biomolecular condensate containing the RNA degradosome mRNA decay machinery, but the biochemical function of such organization remains poorly defined. Here we define the RNA substrates of BR-bodies through enrichment of the bodies followed by RNA-seq. We find that long, poorly translated mRNAs, small RNAs, and antisense RNAs are the main substrates, while rRNA, tRNA, and other conserved ncRNAs are excluded from these bodies. BR-bodies stimulate the mRNA decay rate of enriched mRNAs, helping to reshape the cellular mRNA pool. We also observe that BR-body formation promotes complete mRNA decay, avoiding the build-up of toxic endo-cleaved mRNA decay intermediates. The combined selective permeability of BR-bodies for both, enzymes and substrates together with the stimulation of the sub-steps of mRNA decay provide an effective organization strategy for bacterial mRNA decay.

biochemistry↗