1. Identification of a novel gene in ROD9 island of Salmonella Enteritidis involved in the alteration of virulence-associated genes expression
- Author
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Susmita Das, Bikash R. Sahu, Mrutyunjay Suar, Shilpa Ray, and Daniel Ryan
- Subjects
0301 basic medicine ,Serotype ,Salmonella ,C57BL/6 ,medicine.disease_cause ,SPI-19 ,Genes, Regulator ,Cells, Cultured ,SEN1005 ,Salmonella Enteritidis ,invasion ,Editorial ,Infectious Diseases ,motility ,Salmonella enterica ,Salmonella Infections ,Identification (biology) ,Microbiology (medical) ,Genomic Islands ,ROD9 ,Virulence Factors ,Salmonella enteritidis ,Immunology ,Virulence ,Biology ,Microbiology ,lcsh:Infectious and parasitic diseases ,03 medical and health sciences ,protein secretion ,medicine ,Animals ,Humans ,lcsh:RC109-216 ,Gene ,SPI-1 ,Gene Expression Profiling ,Macrophages ,Epithelial Cells ,Gene Expression Regulation, Bacterial ,biology.organism_classification ,Virulence associated genes ,Mice, Inbred C57BL ,virulence ,Disease Models, Animal ,030104 developmental biology ,Genes, Bacterial ,Genetic Loci ,Mutagenesis ,inflammation ,Parasitology ,gene regulation ,Gene Deletion - Abstract
Salmonella enterica subsp. I serovar Enteritidis (S. Enteritidis), one of the causative agents for non-typhoidal gastrointestinal diseases in humans is an intracellular bacterium and mechanism for its invasion into host cells is critical to cause infection. The virulence of the pathogen is explained by the expression of genes located on its pathogenicity islands, mostly encoded under SPI-1 and SPI-2. However, S. Typhimurium SL1344, despite sharing ∼98% of its genome with S. Enteritidis P125109, lacks few regions of differences (ROD) that are hypothesized to impart virulence potential to S. Enteritidis. In this study, we created different mutants in the ROD9 island of S. Enteritidis, also referred as SPI-19 and identified a novel locus, SEN1005, encoding a hypothetical protein that is involved in its pathogenesis. ΔSEN1005 displayed significantly reduced entry into cultured epithelial cells as well as uptake by macrophages and failed to cause acute colitis in C57BL/6 mice at day 3 post-infection (p.i.). Additionally, the global transcriptome analysis revealed a highly repressed SPI-1 and other down-regulated genes responsible for flagellar assembly, chemotaxis and motility in the mutant which correlated with decreased invasion and abated inflammation as compared to the wild-type. Therefore, our findings revealed that ΔSEN1005 was attenuated in vitro as well as in vivo and we propose this hypothetical protein to play a role in altering the expression of genes involved in Salmonella virulence. more...
- Published
- 2018