- Enterococcus faecalis
color = lightgrey
name = "Enterococcus faecalis"
image_width = 240px
image_caption = "Enterococcus faecalis" as viewed through a
scanning electron microscope
regnum = Bacteria
genus = "
species = "E. faecalis"
binomial = "Enterococcus faecalis"
binomial_authority = (Orla-Jensen 1919)
Schleifer & Kilpper-Bälz 1984
"Enterococcus faecalis" – formerly classified as part of the Group D "
Streptococcus" system – is a Gram-positive commensal bacteriuminhabiting the gastrointestinal tracts of humans and other mammals.cite book | author = Ryan KJ, Ray CG (editors) | title = Sherris Medical Microbiology | edition = 4th ed. | pages = p. 294––5 | publisher = McGraw Hill | year = 2004 | isbn = 0-8385-8529-9 ] A commensal organism like other species in the genus" Enterococcus", "E. faecalis" can cause life-threatening infections in humans, especially in the nosocomial(hospital) environment, where the naturally high levels of antibiotic resistance found in "E. faecalis" contribute to its pathogenicity.
"E. faecalis" is a non-motile microorganism and facultatively anaerobic; it ferments
glucosewithout gas production, and does not produce a catalasereaction with hydrogen peroxide. "E. faecalis" displays gamma hemolysis(γ-hemolysis). It produces a reduction of litmus milk, but does not liquefy gelatin. Growth of nutrient broth is consistent with being facultatively anaerobic.
"E. faecalis" can cause
endocarditis, as well as bladder, prostate, and epididymal infections; nervous system infections are less common.cite book | author = Pelletier LL | title = Microbiology of the Circulatory System. "in:" Baron's Medical Microbiology "(Baron S "et al", eds.)| edition = 4th ed. | publisher = Univ of Texas Medical Branch | year = 1996 | url = http://www.ncbi.nlm.nih.gov/books/bv.fcgi?highlight=Lancefield&rid=mmed.section.5077 | isbn = 0-9631172-1-1 ]
"E. faecalis" is resistant to many commonly used
antimicrobialagents ( aminoglycosides, aztreonam, cephalosporins, clindamycin, the semi-synthetic penicillins nafcillinand oxacillin, and trimethoprim-sulfamethoxazole). Resistance to vancomycinis also becoming more common. [cite journal |author=Amyes SG |title=Enterococci and streptococci |journal=Int. J. Antimicrob. Agents |volume=29 Suppl 3 |issue= |pages=S43–52 |year=2007 |month=May |pmid=17659211 |doi=10.1016/S0924-8579(07)72177-5 |url=http://linkinghub.elsevier.com/retrieve/pii/S0924-8579(07)72177-5] [cite journal |author=Courvalin P |title=Vancomycin resistance in gram-positive cocci |journal=Clin. Infect. Dis. |volume=42 Suppl 1 |issue= |pages=S25–34 |year=2006 |month=January |pmid=16323116 |doi=10.1086/491711 |url=http://www.journals.uchicago.edu/doi/abs/10.1086/491711?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dncbi.nlm.nih.gov] Exposure to cephalosporinis a particularly important risk factor for colonization and infection with enterococci.
Prior to 1984, enterococci were members of the genus "
Streptococcus": thus "E. faecalis" was known as "Streptococcus faecalis".cite journal | author = Schleifer KH; Kilpper-Balz R | title = Transfer of "Streptococcus faecalis" and "Streptococcus faecium" to the genus "Enterococcus" nom. rev. as "Enterococcus faecalis" comb. nov. and "Enterococcus faecium" comb. nov | journal= Int. J. Sys. Bacteriol. | year= 1984 | volume= 34 | issue= | pages= 31–34 | url= ]
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