Project description:Screen for differences in gene expression between a parental Salmonella enterica serovar Enteritidis strain (ATCC4931) and an adapted strain with increased resistance to the widely used antimicrobial sanitizer dodecyltrimethylammonium chloride (DTAC)
Project description:Screen for differences in gene expression between a parental Salmonella enterica serovar Enteritidis strain (ATCC4931) and an adapted strain with increased resistance to the widely used antimicrobial sanitizer dodecyltrimethylammonium chloride (DTAC) Time course of comparative gene expression changes between log phase parental and adapted Enteritidis strains after 0, 10, 30 and 150 min of exposure to 50% of the respective MIC of DTAC.
Project description:Multidrug-resistant (MDR; resistance to >3 antimicrobial classes) Salmonella enterica serovar I 4,[5],12:i:- strains were linked to a 2015 foodborne outbreak from pork. Strain USDA15WA-1, associated with the outbreak, harbors an MDR module and the metal tolerance element Salmonella Genomic Island 4 (SGI-4). Characterization of SGI-4 revealed that conjugational transfer of SGI-4 resulted in the mobile genetic element (MGE) replicating as a plasmid or integrating into the chromosome. Tolerance to copper, arsenic, and antimony compounds was increased in Salmonella strains containing SGI-4 compared to strains lacking the MGE. Following Salmonella exposure to copper, RNA-seq transcriptional analysis demonstrated significant differential expression of diverse genes and pathways, including induction of numerous metal tolerance genes (copper, arsenic, silver, and mercury). Evaluation of swine administered elevated concentrations of zinc oxide (2,000 mg/kg) and copper sulfate (200 mg/kg) as an antimicrobial feed additive (Zn+Cu) in their diet for 4 weeks prior to and 3 weeks post-inoculation with serovar I 4,[5],12:i:- indicated that Salmonella shedding levels declined at a slower rate in pigs receiving in-feed Zn+Cu compared to control pigs (no Zn+Cu). The presence of metal tolerance genes in MDR Salmonella serovar I 4,[5],12:i:- may provide benefits for environmental survival or swine colonization in metal-containing settings.
Project description:A collection of 61 Salmonella enterica serovar Typhimurium (S. Typhimurium) of animal and human origin, matched as closely as possible by phage type, antimicrobial resistance pattern and place / time of isolation, and sourced from farms or hospitals in Scotland, were analysed by antimicrobial susceptibility testing, phage typing, pulsed field gel electrophoresis (PFGE), plasmid profiling and DNA microarrays. PFGE of all 61 isolates revealed ten PFGE profiles, which clustered by phage type and antibiotic resistance pattern, with human and animal isolates distributed between PFGE profiles. Analysis of 23 representative S. Typhimurium strains hybridised to a composite Salmonella DNA microarray identified a small number of specific regions of genome variation between different phage types and PFGE profiles. These variable regions of DNA were typically located within prophage-like elements. Simple PCR assays were subsequently designed to discriminate between different isolates from the same geographical region.
Project description:Salmonella enterica causes serious global burden of morbidity and mortality and is a major cause of infant bacteremia in sub Saharan Africa. Diseases caused by Salmonella are treatable with antibiotics but successful antibiotic treatment has become difficult due to antimicrobial resistance. An effective vaccine together with public health effort may therefore be a better strategy to control these infections. Protective immunity against Salmonella depends primarily on T cell-mediated immune responses and therefore identifying relevant T cell antigens is necessary for Salmonella vaccine development. Our laboratory has used an immunoproteomics approach to identify Chlamydia T cell antigens that exhibited significant protection against Chlamydia infection in mice. In this study, we infected murine bone marrow derived dendritic cells from C57BL/6 mice with Salmonella enterica strain SL1344 followed by isolation of MHC class I and II- molecules and elution of bound peptides. The sequences of the peptides were then identified using tandem mass spectrometry. We identified 87 MHC class II and 23 MHC class I Salmonella derived peptides. Four of 12 peptides stimulated IFN-? production by CD4 T cells from the spleens of mice with persistent Salmonella infection. These antigens will be useful for Salmonella immunobiology research and are potential Salmonella vaccine candidates.
2016-12-14 | PXD004451 | Pride
Project description:Antimicrobial resistance of Salmonella isolates recovered from retail chicken in UAE
Project description:Antimicrobial exposure can potentially lead to increased antimicrobial resistance plasmid transfer. RNA sequencing data was collected from conjugal pairs of Salmonella enterica and Escherichia coli exposed or not exposed to tetracycline over a time course to determine differences in transcript numbers associated with conjugation and tetracycline exposure. The samples were sequenced on the Illumina HiSeq X10 platform with the 150-bp paired-end kit. Among the most highly up-regulated genes in the tetracycline exposed samples were also tetracycline efflux pump genes across the timepoints. In addition, some conjugal transfer-associated genes (e.g. traJ and traA) were upregulated in the tetracycline exposed samples.