The enteric pathogen Salmonella enterica is exposed to a number of stressful environments during its life cycle within and outside its various hosts. During intestinal colonisation Salmonella is successively exposed to acid pH in the stomach, to the detergent-like activity of bile, to decreasing oxygen supply, to the presence of multiple metabolites produced by the normal gut microflora and finally it is exposed to cationic antimicrobial peptides present on the surface of epithelial cells. There are four major regulators controlling relevant stress responses in Salmonella, namely RpoS, PhoPQ, Fur and OmpR/EnvZ. Except for Fur, inactivation of genes encoding the other stress regulators results in attenuated virulence and such mutants can therefore be considered as vaccine candidates. In contrast, a decrease in oxygen supply monitored by Fnr and ArcAB, or oxidative stress controlled by OxyR and SoxRS is not regarded as a stress associated with host colonisation since inactivation of either of these systems does not result in reductions in colonisation. The role of quorum-sensing through luxS and sdiA is also considered as a regulator of virulence and colonisation.
- MeSH
- Bacterial Proteins genetics metabolism MeSH
- Financing, Organized MeSH
- Hydrogen-Ion Concentration MeSH
- Humans MeSH
- Heat-Shock Response MeSH
- Gene Expression Regulation, Bacterial MeSH
- Salmonella enteritidis physiology pathogenicity growth & development MeSH
- Salmonella typhimurium physiology pathogenicity growth & development MeSH
- Salmonella Infections microbiology MeSH
- Intestines microbiology MeSH
- Virulence MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
3rd ed. XIX, 331 s. : tab., grafy ; 25 cm
Sexually transmitted diseases, ISSN 0148-5717 vol. 35, no. 12, suppl. December 2008
44 s. : il., tab. ; 28 cm
- MeSH
- Black or African American MeSH
- Health Status Disparities MeSH
- Sexually Transmitted Diseases epidemiology MeSH
- Sexual Behavior MeSH
- Socioeconomic Factors MeSH
- Health Care Quality, Access, and Evaluation MeSH
- Publication type
- Collected Work MeSH
- Conspectus
- Veřejné zdraví a hygiena
- NML Fields
- dermatovenerologie
- Keywords
- doba stěhování národů, germánské kmeny,
- MeSH
- Anthropology, Physical * history methods MeSH
- Anthropometry history methods MeSH
- Archaeology history methods MeSH
- Adult MeSH
- Histological Techniques methods utilization MeSH
- Bone and Bones anatomy & histology pathology injuries MeSH
- Skeleton * MeSH
- Humans MeSH
- Pelvis pathology injuries MeSH
- Tomography, X-Ray Computed methods utilization MeSH
- Mortuary Practice MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Female MeSH
- Publication type
- Historical Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Czech Republic MeSH
The origin of multidrug-resistant Salmonella enterica serovar typhimurium (S. typhimurium) harboring the Salmonella Genomic Island 1 (SGI1), which was detected for the first time in the mid-1980s is unknown. In this study, we performed microarray genomotyping of four multidrug-resistant SGI1 positive strains and found that unlike the S. typhimurium LT2 strain, the multidrug-resistant strains lacked genes STM0517-0529 allowing the utilization of allantoin as a sole nitrogen source. We extended this observation by PCR screening of additional 120 S. typhimurium field strains and found that this locus was absent in all SGI1 positive and also in 24% of SGI1 negative strains, which were proposed to be the original recipients of SGI1. To prove this hypothesis, we compared the STM0517-0529 negative strains (with or without the SGI1) by PFGE and PCR prophage typing and found that 8 out of 11 of the SGI1 negative strains and 17 out of 22 SGI1 positive strains were of identical PFGE pattern and PCR prophage pattern, while this specific pattern was never observed among STM0517-0529 positive strains. We therefore propose that a lineage of the S. typhimurium DT104 sensitive strain first lost the ability to metabolize allantoin and then acquired SGI1.
- MeSH
- Anti-Bacterial Agents pharmacology MeSH
- DNA, Bacterial genetics MeSH
- Financing, Organized MeSH
- Genomic Islands MeSH
- Microarray Analysis MeSH
- Drug Resistance, Multiple, Bacterial genetics MeSH
- Salmonella enterica genetics drug effects MeSH
- Salmonella typhimurium isolation & purification MeSH
- Salmonella Infections microbiology MeSH
- Bacterial Typing Techniques MeSH
