Enterococcus

Source: Wikipedia, the free encyclopedia.
Not to be confused with Enterobacter.

Enterococcus
Enterococcus sp. infection in
pulmonary
tissue
Scientific classification Edit this classification
Domain: Bacteria
Phylum: Bacillota
Class: Bacilli
Order: Lactobacillales
Family: Enterococcaceae
Genus: Enterococcus
(ex Thiercelin & Jouhaud 1903)
Schleifer & Kilpper-Bälz 1984
Species[1]

Enterococcus is a large

commensal organisms in the intestines of humans: E. faecalis (90–95%) and E. faecium (5–10%). Rare clusters of infections occur with other species, including E. casseliflavus, E. gallinarum, and E. raffinosus.[2]

Physiology and classification

Enterococci are facultative anaerobic organisms, i.e., they are capable of cellular respiration in both oxygen-rich and oxygen-poor environments.[3] Though they are not capable of forming spores, enterococci are tolerant of a wide range of environmental conditions: extreme temperature (10–45 °C), pH (4.6–9.9), and high sodium chloride concentrations.[4]

Enterococci exhibit variable

blood agar. Differences occur between species, and between strains of species. More virulent organisms are more likely to exhibit alpha (partial) or beta (complete) hemolysis than less virulent specimens of Enterococcus, which frequently exhibit gamma (absent) hemolysis.[5]

History

Members of the genus Enterococcus (from Greek έντερο, éntero 'intestine' and κοκκος, coccos 'granule') were classified as group D Streptococcus until 1984, when genomic DNA analysis indicated a separate genus classification would be appropriate.[6]

Evolution

This genus appears to have evolved 425 million years ago to 500 million years ago.[7]

Pathology

Important clinical infections caused by Enterococcus include

bacterial endocarditis, diverticulitis, meningitis, and spontaneous bacterial peritonitis.[4][8][9] Sensitive strains of these bacteria can be treated with ampicillin, penicillin and vancomycin.[10] Urinary tract infections can be treated specifically with nitrofurantoin, even in cases of vancomycin resistance.[11]

Example of a workup algorithm of possible bacterial infection in cases with no specifically requested targets (non-bacteria, mycobacteria etc.), with most common situations and agents seen in a New England community hospital setting. Enterococcus is included near bottom-center.

Meningitis

Main article: Meningitis

Enterococcal meningitis is a rare complication of neurosurgery. It often requires treatment with intravenous or

intrathecal vancomycin, yet it is debatable as to whether its use has any impact on outcome: the removal of any neurological devices is a crucial part of the management of these infections.[12]
New epidemiological evidence has shown that enterococci are major infectious agent in chronic bacterial prostatitis.[13] Enterococci are able to form biofilm in the prostate gland, making their eradication difficult.[citation needed] Cases of enterococcal meningitis, in the absence of trauma or surgery, should raise suspicion of an underlying intestinal pathology (e.g., strongyloidiasis).[14]

Antibacterial resistance

From a medical standpoint, an important feature of this genus is the high level of

nosocomial infections of hospitalized patients, especially in the US.[4] Other developed countries, such as the UK, have been spared this epidemic, and, in 2005, Singapore managed to halt an epidemic of VRE.[15] Although quinupristin/dalfopristin (Synercid) was previously indicated for treatment of VRE in the USA, the FDA approval for this indication has since been retracted.[16] The rationale for the retraction of Synercid's indication for VRE was based upon poor efficacy in E. faecalis, which is implicated in the vast majority of VRE cases.[17][18] Tigecycline has also been shown to have antienterococcal activity, as has rifampicin.[19]

Bacillus haynesii CD223 and Advenella mimigardefordensis SM421 can inhibit the growth of Enterococcus spp. [20]

Water quality

In bodies of water, the acceptable level of contamination is very low; for example in the state of Hawaii, and most of the United States, the limit for water off its beaches is a five-week geometric mean of 35 colony-forming units per 100 ml of water, above which the state may post warnings to stay out of the ocean.[21] In 2004, measurement of enterococci took the place of fecal coliforms as the new American federal standard for water quality at public saltwater beaches and alongside Escherichia coli at freshwater beaches.[22] It is believed to provide a higher correlation than fecal coliform with many of the human pathogens often found in city sewage.[23]

References

  1. ^
    LPSN
    ).
  2. ^
    ISBN 978-1-55581-234-8
    .
  3. ISBN 1-55581-166-3
    .
  4. ^
    PMID 19383684
    .
  5. PMID 12791882
    .
  6. doi:10.1099/00207713-34-1-31
    .
  7. PMID 28502769
    .
  8. ^
    ISBN 0-8385-8529-9
    .
  9. PMID 29109849
    .
  10. PMID 21413321
    .
  11. PMID 11120989
    .
  12. S2CID 24189202
    .
  13. ^ "Enterococcus sp rRNA [Presence] in Specimen by Probe". Logical Observation Identifiers Names and Codes (LOINC). Regenstrief Institute, Inc. 5001-3.
  14. PMID 38075422
    .
  15. PMID 18371517
    .
  16. PMID 11572153
    .
  17. PMID 8460927
    .
  18. PMID 12019099
    .
  19. ^ "Enterococcus sp DNA [Presence] by NAA with probe detection in Positive blood culture". Logical Observation Identifiers Names and Codes (LOINC). Regenstrief Institute, Inc. 92784-8.
  20. PMID 36453920
    .
  21. ^ "Clean Water Branch" (PDF). Hawaii State Department of Health. Archived from the original (PDF) on 2011-11-11. Retrieved 2012-05-18.
  22. ^ "Water Quality Standards for Coastal and Great Lakes Recreation Waters; Final Rule". Federal Register. 69 (220): 67218–67243. 16 November 2004. Retrieved 26 November 2014.
  23. S2CID 35780753
    .

External links

Retrieved from "https://en.wikipedia.org/w/index.php?title=Enterococcus&oldid=1216670025"