Salmonella enterica
Salmonella enterica | |
---|---|
S. enterica Typhimurium colonies on a Hektoen enteric agar plate | |
Scientific classification | |
Domain: | Bacteria |
Phylum: | Pseudomonadota |
Class: | Gammaproteobacteria |
Order: | Enterobacterales |
Family: | Enterobacteriaceae |
Genus: | Salmonella |
Species: | S. enterica
|
Binomial name | |
Salmonella enterica (ex Kauffmann & Edwards 1952) Le Minor & Popoff 1987
| |
Subspecies | |
Salmonella enterica (formerly Salmonella choleraesuis) is a
Pathogenesis
Secreted proteins are of major importance for the
DNA repair capability
Exposure of S. enterica to bile salts, such as sodium deoxycholate, induces the SOS DNA damage response indicating that in this organism bile salts cause DNA damage.[4] Bile salt exposure is found to increase GC to AT transition mutations and also to induce genes of the OxyR and SoxRS regulons suggesting further that bile salts specifically cause oxidative DNA damage.[4] Mutants of S. enterica that are defective in enzymes required for the process of base excision repair are sensitive to bile salts. This indicates that wild-type S. enterica uses base excision repair to remove DNA damages caused by the bile salts.[4] The RecBCD enzyme which functions in recombinational repair of DNA is also required for bile salt resistance.[citation needed]
Small noncoding RNA
Small nonprotein-coding RNAs (sRNA) are able to perform specific functions without being translated into proteins; 97 bacterial sRNAs from Salmonella Typhi were discovered.[5]
AsdA (antisense RNA of dnaA) is a cis-encoded antisense RNA of dnaA described in S. enterica serovar Typhi. It was discovered by deep sequencing and its transcription was confirmed by Northern blot and RACE analysis. AsdA is estimated to be about 540 nucleotides long, and represents the complementary strand to that encoding DnaA, a protein that plays a central role in the initiation of DNA replication and hence cellular division. In rich media, it is highly expressed only after reaching the stationary growth phase, but under limiting iron or osmotic stress, it is already expressed during exponential growth. Overexpression of AsdA stabilizes dnaA mRNA, increasing its levels and thereby enhancing its rate of translation. This suggests that AsdA is a regulator of DNA replication.[6]
Nomenclature
S. enterica has six subspecies, and each subspecies has associated
S. e. subsp. arizonae, named after the state of Arizona, is most commonly found in cold-blooded animals (especially snakes), but can also infect turkey, sheep, and humans. It is endemic in southwestern United States.[10] The similar S. e. subsp. diarizonae also infects snakes and occasionally humans.[11]
Epidemiology
Most cases of salmonellosis are caused by food infected with S. enterica, which often infects cattle and poultry, though other animals such as domestic cats[12][13] and hamsters[14] have also been shown to be sources of infection in humans. It primarily resides in the intestinal tract of animals of humans and can be found in feedstuff, soil, bedding, litter, and fecal matter.[15]
The primary reservoir for the pathogen is poultry and 70% of human cases are attributed with the consumption of contaminated eggs, chicken, or turkey.
S. enterica genomes have been reconstructed from up to 6,500 year old human remains across Western Eurasia, which provides evidence for geographic widespread infections with systemic S. enterica during prehistory, and a possible role of the
Children under the age of 5 years, the elderly, and immunosuppressed adults are at an increased risk of systemic dissemination of the disease and need specialized treatment in order to combat the disease. Drinking extra fluids and antibacterial agents such as fluoroquinolones are typical treatment plans for Salmonella enterica.[21] Complications of the disease often appear as anemia or septicaemia and the mortality rate is 15% once these symptoms arise.[22]
See also
- 1984 Rajneeshee bioterror attack
- AsrC small RNA
- Bacterial small RNA
- HilD 3'UTR
- IsrM small RNA
- PinT small RNA
- Typhoid Mary
References
- .
- PMID 23462113.
- ISBN 978-1-904455-42-4.
- ^ PMID 16888329.
- PMID 20460466.
- PMID 23637809.
- ^ Todar K. "Salmonella and Salmonellosis". Todar's Online Textbook of Bacteriology.
- ISBN 978-0-323-05470-6.
- PMID 31190705.
- PMID 27938338.
- PMID 14711697.
- ^ Grünberg W (October 2022). "Salmonellosis in Animals – Digestive System". MSD Veterinary Manual. Rahway, NJ, USA: Merck & Co., Inc. Retrieved 2021-01-01.
- PMID 28738871.
- PMID 17202452.
- PMID 25664339.
- ^ Dewey-Mattia D, Kisselburgh H, Manikonda K, Silver R, Subramhanya S, Sundararaman P, et al. "Surveillance for foodborne disease outbreaks – United States, 2016 : annual report". stacks.cdc.gov. Retrieved 2023-11-02.
- PMID 22980012.
- PMID 17133798.
- PMID 32094538.
- S2CID 3358440.
- ^ Owens MD, Warren DA, Louden M (8 March 2021). Talavera F (ed.). "Salmonella Infection in Emergency Medicine Medication: Antibiotics, Antidiarrheals, Glucocorticoids". emedicine.medscape.com. Retrieved 2023-11-02.
- PMID 35114140.
External links
- Notes on Salmonella nomenclature
- Salmonella+enterica at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
- Current research on Salmonella typhimurium at the Norwich Research Park
- "Salmonella enterica". NCBI Taxonomy Browser. 28901.
- Type strain of Salmonella enterica at BacDive – the Bacterial Diversity Metadatabase