Project description:Salmonella Heidelberg is currently the 9th common serovar and has more than twice the average incidence of blood infections in Salmonella. A recent Salmonella Heidelberg outbreak in chicken infected 634 people during 2013-2014, with a hospitalization rate of 38% and an invasive illness rate of 15%. While the company’s history suggested longstanding sanitation issues, the strains’ characteristics which may have contributed to the outbreak are unknown. We hypothesized that the outbreak strains of S. Heidelberg might possess enhanced stress tolerance or virulence capabilities. Consequently, we obtained nine food isolates collected during the outbreak investigation and several reference isolates and tested their tolerance to processing stresses, their ability to form biofilms, and their invasiveness in vitro. We further performed RNA-sequencing on three isolates with varying heat tolerance to determine the mechanism behind our isolates’ enhanced heat tolerance. Ultimately, we determined that (i) many Salmonella Heidelberg isolates associated with a foodborne outbreak have enhanced heat resistance (ii) Salmonella Heidelberg outbreak isolates have enhanced biofilm-forming ability under stressful conditions, compared to the reference strain (iii) exposure to heat stress may also increase Salmonella Heidelberg isolates’ antibiotic resistance and virulence capabilities and (iv) Salmonella Heidelberg outbreak-associated isolates are primed to better survive stress and cause illness. This data helps explain the severity and scope of the outbreak these isolates are associated with and can be used to inform regulatory decisions on Salmonella in poultry and to develop assays to screen isolates for stress tolerance and likelihood of causing severe illness.
Project description:The deposited microarray data were generated in a study that integrated the gene expression profiles and metabolic responses of Caco2 cells incubated with Bifidobacterium infantis subsp. infantis and Salmonella enterica subsp. enterica sv. Typhimurium. The aim of this study was to investigate the interaction of B. infantis, S. Typhimurium, and host cells (Caco2) in the course of infection to understand the molecular mechanics of probiotic-pathogen-host interactions.
2024-05-08 | GSE266880 | GEO
Project description:Whole Genome Sequencing of Salmonella Infantis Isolates
| PRJNA1125001 | ENA
Project description:Foodborne Salmonella enterica Isolates from Russia
Project description:The non-typhoidal Salmonella enterica serotype Heidelberg is a major foodborne pathogen primarily transmitted to humans through contaminated poultry products. Current control measures emphasize novel approaches to mitigate Salmonella Heidelberg colonization in poultry and the contamination of poultry products, thereby reducing its transmission to humans. This study highlight that commensal E. coli 47-1826 can potentially be used to control of S. Heidelberg 18-9079 in poultry
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: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:Foodborne illness from contaminated fresh produce has increased over the past decade, with the enteric human pathogen Salmonella enterica being frequently implicated in foodborne illness outbreaks associated with tomato consumption. Our previous work demonstrated that Salmonella responds to tomato cultivar differences, but knowledge of the underlying genetic responses is limited. To identify the mechanisms permitting this human pathogen-plant commodity association, a genome-wide transcriptomic analysis of Salmonella on tomato shoots and roots was conducted using an RNA-seq approach. Expression signal for 4,556 out of 4,745 annotated chromosomal and plasmid genes was obtained, indicating >96% coverage of the whole S. Typhimurium transcriptome. Identified key signals of differential expression related to cellular processes preserving viability while dealing with multiple biotic stresses and limited nutrient availability, compared to growth in nutrient-rich medium. Data suggest that sulfur metabolism, anaerobic respiration, nitrosative and oxidative stress tolerance and biofilm formation may be crucial functions for Salmonella survival on tomato. Some effector protein genes from pathogenicity island-2 were expressed, though their function in this niche is largely unknown. A large proportion of up-regulated genes remain uncharacterized, pointing to as yet undescribed strategies that allow enteric pathogens to associate with plants during transit in the environment to herbivorous hosts.
Project description:Salmonella enterica is an important foodborne pathogen that utilizes secreted effector proteins to manipulate host pathways to facilitate survival and dissemination. Different S. enterica serovars cause disease syndromes ranging from self-limited gastroenteritis to typhoid fever and vary in their repertoire of effectors. We leveraged this natural diversity to identify stm2585, here designated sarA (Salmonella anti-inflammatory response activator), as a Salmonella effector secreted primary by the SPI-2 type III secretion system. SarA is necessary and sufficient to induce STAT3 phosphorylation and IL-10 production, contributing to intracellular replication in vitro and bacterial load at systemic sites in mice. These results demonstrate that Salmonella has evolved effector mechanisms for regulating a host anti-inflammatory signaling pathway important in infection, autoimmunity, and cancer.