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
Project description:Even though the incidence of salmonellosis in humans has decreased over the last years, Salmonella spp. are still a leading cause of foodborne outbreaks in Europe (Anon., 2014). Of more than 2500 different serovars of Salmonella enterica, S. enterica serovar Enteritidis (S. Enteritidis) is the most frequently reported serovar in relation to food borne disease, and egg and egg products are the most important vehicles (Anon., 2014). It has recently been shown that S. Enteritidis is superior to other serovars tested regarding survival in egg white, which may explain why many egg borne outbreaks are caused by this serovar (De Vylder et al., 2013). The genetic background for this apparent better adaptation to survival in egg is only partially known. The aim of this work was to carry out gene expression analysis in order to understand how S. Enteritidis adapts to growth in the hostile environment of egg. This study analyzed gene expression of this bacterium during growth in whole egg, and whether highly expressed genes were essential for the growth. High quality RNA was extracted from S. Enteritidis using an improved modified RNA-extraction protocol. Global gene expression during growth in whole egg was compared to growth in LB-medium using DNA array method. Twenty-six genes were significantly upregulated during growth in egg; these belonged to amino acids biosynthesis, di/oligopeptide transport system, biotin synthesis, ferrous iron transport system, and type III secretion system. Significant downregulation of 15 genes related to formate hydrogenlyase (FHL) and trehalose metabolism was observed. The results suggested that S. Enteritidis is starved for amino-acids, biotin and iron when growing in egg.
Project description:Transcriptional profiles of mid-exponentially growing Salmonella enterica sv Enteritidis PT8 cultures in response to exposure to trans-cinnamaldehyde (0.01%; 0.75mM) or eugenol (0.04%; 2.46mM) Overall design: Total RNA was harvested from three biological replicates of mid-exponentially growing Salmonella enterica sv Enteritidis PT8 cultures before or after 15min or 30 min exposure to plant-derived compounds trans-cinnamaldehyde (0.01%) or eugenol (0.04%) at subinhibitory concentrations.
Project description:Single-molecule read technologies allow for detection of epigenomic base modifications during routine sequencing by analysis of kinetic data during the reaction, including the duration between base incorporations at the elongation site (the "inter-pulse duration.") Methylome data associated with a closed de novo bacterial genome of Salmonella enterica subsp. enterica serovar Javiana str. CFSAN001992 was produced and submitted to the Gene Expression Omnibus. Single-sample sequencing and base modification detection of cultured isolate of a foodborne pathogen.
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: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:Investigation of whole genome gene expression level changes in a Salmonella enterica serovar Typhimurium UK1 delta-iacP mutant, compared to the wild-type strain. IacP is resoponsible for the secretion of virulence effector proteins via the type III secretion system, thereby contributing the virulence of S. Typhimurium. The mutants analyzed in this study are further described in Kim et al. 2011. Role of Salmonella Pathogenicity Island 1 Protein IacP in Salmonella enterica Serovar Typhimurium Pathogenesis. Infection and Immunity 79(4):1440-1450 (PMID 21263021). A chip study using total RNA recovered from two separate wild-type cultures of Salmonella enterica serovar Typhimurium UK1 and two separate cultures of a mutant strain, Salmonella enterica serovar Typhimurium UK1 delta-iacP. Each chip measures the expression level of 4,302 genes from Salmonella enterica serovar Typhimurium.