Project description:Microarray based CGH was conducted over a group of 29 strains of S. Enteritidis spanning different epidemiological periods in Uruguay, plus 6 other S. Enteritidis strains isolated from distant geographical regions. We also included 9 Salmonella enterica strains of other serovars isolated in Uruguay. A S. Enteritidis dispensable genome of 233 chromosomal genes and high extent of variation in virulence plasmid was found. Strains isolated before the epidemic show the highest genomic differences as compared with the PT4 reference strain. Comparison with the gene content of other serovars demonstrate extensive horizontal gene transfer between circulating strains beyond serovar definition. Our results show that the epidemic of S Enteritidis in Uruguay was produced by the introduction of strains closely related to PT4, and corroborate the extensive genetic homogeneity among S. Enteritidis isolates worldwide. Phage SE14 emerges as the only specific region for S. Enteritidis. Genetic differences detected in pre-epidemic strains, mainly associated with the absence of phage SE20, suggest that genetic features encoded in this phage may be related to particular epidemiological behavior.
Project description:Effect of mutation of rfaH on gene expression in Salmonella enterica serovar Enteritidis PT4 and Salmonella enterica serovar Typhimurium 4/74
Project description:This is a dynamic mathematical model describing the development of the cellular branch of the intestinal immune system of poultry during the first 42 days of life, and of its response towards an oral infection with Salmonella enterica serovar Enteritidis.
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:Comparative genomic hybridization of a temporally and locally diverse set of S. enterica ssp I serovar Enteritidis isolates, and some closely related serovar Dublin and Gallinarum strains, to the sequenced Enteritidis PT4 Keywords: other
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:Salmonella infections are among the most common foodborne diseases worldwide. The Enteritidis and Dublin serovars of Salmonella enterica are closely related yet they differ significantly in pathogenicity and epidemiology. Enteritidis is a broad-host-range serovar that commonly causes gastroenteritis and infrequently causes invasive disease in humans. Dublin mainly colonizes cattle but upon infecting humans often results in invasive disease. The aim of this work was to elucidate the molecular factors responsible for the differential pathogenic behavior between both serovars. We performed a quantitative proteomic comparative analysis between one clinical isolate of each serovar grown in vitro under gut mimicking conditions (GMC). Compared to S. Enteritidis, the S. Dublin proteome was enriched in proteins linked to response to several stress conditions, such as those encountered during host infection, as well as to virulence. The S. Enteritidis proteome contained proteins related to central anaerobic metabolism pathways that were undetected in S. Dublin. Similar differences were also found at the transcriptional level, as mRNA levels correlated with proteomic results for 17 of the 20 genes tested in 4 natural isolates of each serovar grown in GMC. This work reveals proteomic differences between two Salmonella serovars with markedly different invasive and host-range characteristics, grown in an infection relevant condition, which were not evident in previous comparative genomic analyses.
Project description:Salmonella enterica subsp. enterica contains more than 2,600 serovars of which four are of major medical relevance for humans. While the typhoidal serovars (Typhi and Paratyphi A) are human-restricted and cause enteric fever, non-typhoidal Salmonella serovars (Typhimurium and Enteritidis) have a broad host range and predominantly cause gastroenteritis. In this study, we compared the core proteomes of Salmonella Typhi, Paratyphi A, Typhimurium and Enteritidis using contemporary proteomics. Five isolates, covering different geographical origins, and one reference strain per serovar were grown in vitro to the exponential phase. Protein levels of orthologous proteins between serovars were compared and subjected to gene ontology term enrichment and inferred regulatory interactions. Differential expression of the core proteomes of the typhoidal serovars appears mainly related to cell surface components and, for the non-typhoidal serovars, to pathogenicity. Our findings may guide future development of novel diagnostics and vaccines, and understanding of disease progression.
Project description:The purpose of this experiment was to identify intestinal epithelial responses to various strains of Salmonella enterica. Human intestinal organoids were infected with three serovars of Salmonella; Typhimurium, Enteritidis and Typhi, as well as type 3 secretion system -1 and -2 mutants in Typhimurium in order to identify host responses that were similar and unique to each serovar, and responses that were dependent on these secretion systems.