Streptococcus bovis

''S. bovis'' group

The S. bovis group includes S. equinus, S. gallolyticus, S. infantarius, and other closely related species; they are the nonenterococcal group D streptococci. Members of this group are esculin positive, 6.5% salt negative, sorbitol negative and produce acetoin. Isolates from the S. bovis group are most frequently encountered in blood cultures from patients with colon cancer. However, S. bovis group organisms (especially S. gallolyticus subsp. gallolyticus and S. infantarius subsp. coli) have been associated with endocarditis (3). Although infection with S. bovis group organisms occurs with higher frequency in adults than in pediatric patients, these organisms have been reported to cause neonatal sepsis and meningitis (20).

Classification

S. bovis is a catalase-negative and oxidase-negative, nonmotile, non-sporulating, Gram-positive lactic acid bacterium that grows as pairs or chains of cocci. It is a member of the Lancefield group D streptococci. Most strains are gamma-hemolytic (non-hemolytic), but some also display alpha-hemolytic activity on sheep blood agar plates. Strep bovis is a non-enterococci. Biochemical Tests mannitol salt: negative bile esculin: negative MR/VP: positive/negative nutrient gelatin: negative starch: positive DNase: negative

Human infection

Entry

The main portal of entry for human infection of S. bovis bacteremia is the gastrointestinal tract, but in some cases, entry is through the urinary tract, the hepatobiliary tree, or the oropharynx.

Role in disease

S. bovis is a human pathogen that has been implicated as a causative agent of endocarditis,

S. bovis has long been associated with colorectal cancer; This analysis suggests S. bovis should no longer be regarded as a single bacterial entity in clinical practice. Only Streptococcus gallolyticus (S. bovis biotype I) infection has an unambiguous association with colonic adenomas/carcinomas (prevalence range: 33–71%) that markedly exceeds the prevalence of colonic (pre-)malignancies in the general population (10–25%). Nevertheless, research has not yet determined that S. gallolyticus is a causative agent of colorectal cancer, or if pre-existing cancer makes the lumen of the large intestine more hospitable to its outgrowth.

Ruminal effects

When ruminants consume diets high in starch or sugar, these easily fermentable carbohydrates promote the proliferation of S. bovis in the rumen. Because S. bovis is a lactic acid bacterium, fermentation of these carbohydrates to lactic acid can cause a dramatic decline in ruminal pH, and subsequent development of adverse conditions such as ruminal acidosis or feedlot bloat.

References

References

1. (2002). "Taxonomic dissection of the ''Streptococcus bovis'' group by analysis of manganese-dependent superoxide dismutase gene (sodA) sequences: Reclassification of {{'}}''Streptococcus infantarius'' subsp. ''Coli''{{'}} as ''Streptococcus lutetiensis'' sp. nov. And of ''Streptococcus bovis'' biotype 11.2 as ''Streptococcus pasteurianus'' sp. nov.". International Journal of Systematic and Evolutionary Microbiology.
2. (2016). "An Update on the Streptococcus bovis Group: Classification, Identification, and Disease Associations". Journal of Clinical Microbiology.
3. (2003). "International Committee on Systematics of Prokaryotes Subcommittee on the taxonomy of staphylococci and streptococci: Minutes of the closed meeting, 31 July 2002, Paris, France". International Journal of Systematic and Evolutionary Microbiology.
4. (2016). "An Update on the ''Streptococcus bovis'' Group: Classification, Identification, and Disease Associations". Journal of Clinical Microbiology.
5. (2020). "Bacteremia due to ''Streptococcus gallolyticus'': A Name with an Ominous Significance?". Indian Journal of Critical Care Medicine.
6. Ryan K.J. and C.G. Ray CG (editors). 2004. ''Sherris Medical Microbiology'' (4th ed.). McGraw Hill. {{ISBN. 0-8385-8529-9.
7. (October 13, 1977). "Association of Streptococcus bovis with carcinoma of the colon". New England Journal of Medicine.
8. (2004). "Characterization of ''Streptococcus bovis'' from the rumen of the dromedary camel and Rusa deer". Letters in Applied Microbiology.
9. (2002). "Regulation of fermentation in a ruminal bacterium, ''Streptococcus bovis'', with special reference to rumen acidosis". Animal Science Journal.
10. Lorenz, Ingrid. (June 2022). "Subacute Ruminal Acidosis in Cattle and Sheep, Professional Version". The Merck Veterinary Manual.
11. (2010). "Spontaneous bacterial peritonitis caused by Streptococcus bovis: case report and review of the literature". Brazilian Journal of Infectious Diseases.
12. (2003). "Reappraisal of the taxonomy of the ''Streptococcus bovis/Streptococcus equinus'' complex and related species: description of ''Streptococcus gallolyticus'' subsp. ''gallolyticus'' subsp. nov., ''S. gallolyticus'' subsp. ''macedonicus'' subsp. nov. and ''S. gallolyticus'' subsp. ''pasteurianus'' subsp. nov". International Journal of Systematic and Evolutionary Microbiology.
13. Mazumder, Shirin A. (2018-11-30). "Group D Streptococcus (GDS) Infections (Streptococcus bovis/Streptococcus gallolyticus): Background, Pathophysiology, Epidemiology". EMedicine.
14. (February 1978). "Fulminant neonatal septicemia caused by Streptococcus bovis". Journal of Pediatrics.
15. (November 2002). "Streptococcus bovis bacteremia and fetal death". Obstetrics and Gynecology.
16. (1 January 2000). "Streptococcus bovis meningitis in an infant". Journal of Clinical Microbiology.
17. (November 2011). "Clinical Importance of Streptococcus gallolyticus infection among colorectal cancer patients: systematic review and meta-analysis.". Clinical Infectious Diseases.
18. zur Hausen H. (November 2006). "Streptococcus bovis: causal or incidental involvement in cancer of the colon?". International Journal of Cancer.
19. (2012). "Association between Bacteremia Due to Streptococcus gallolyticus subsp. gallolyticus (Streptococcus bovis I) and Colorectal Neoplasia: ACase-Control Study". Clinical Infectious Diseases.