Enterococcus

Taxobox
color = lightgrey
name = "Enterococcus"

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image_width = 240px
image_caption = "Enterococcus sp." infection in pulmonary tissue.
regnum = Bacteria
divisio = Firmicutes
classis = Bacilli
ordo = Lactobacillales
familia = Enterococcaceae
genus = "Enterococcus"
genus_authority = ("ex" Thiercelin & Jouhaud 1903)
Schleifer & Kilpper-Bälz 1984
subdivision_ranks = Species
subdivision = "E. avium" "E. durans" "E. faecalis" "E. faecium" "E. solitarius" etc.

"Enterococcus" is a genus of lactic acid bacteria of the phylum Firmicutes. Members of this genus were classified as "Group D Streptococcus" until 1984 when genomic DNA analysis indicated that a separate genus classification was appropriate. [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= ]

Enterococci are Gram-positive cocci which often occur in pairs (diplococci) and are difficult to distinguish from "Streptococci" on physical characteristics alone. Two species are common commensal organisms in the intestines of humans: "E. faecalis" (90-95%) and "E. faecium" (5-10%). Enterococci are facultative anaerobic organisms, i.e. they prefer the use of oxygen, but they can survive in the absence of oxygen.cite book | author = Fischetti VA; Novick RP; Ferretti JJ; Portnoy DA; Rood JI (editors) | title = Gram-Positive Pathogens | publisher = ASM Press | year = 2000 | id = ISBN 1-55581-166-3] They typically exhibit gamma-hemolysis on sheep's blood agar.

Pathology

Important clinical infections caused by "Enterococcus" include urinary tract infections, bacteremia, bacterial endocarditis, diverticulitis, and meningitis.cite book | author = Ryan KJ, Ray CG (editors) | title = Sherris Medical Microbiology | edition = 4th ed. | pages = 294–5 |publisher = McGraw Hill | year = 2004 | isbn = 0-8385-8529-9 ] Sensitive strains of these bacteria can be treated with ampicillin and vancomycin.cite book | author = Pelletier LL Jr. | 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?rid=mmed.section.5077 | isbn = 0-9631172-1-1 ]

From a medical standpoint, the most important feature of this genus is their high level of endemic antibiotic resistance. Some Enterococci are resistant to β-lactam-based antibiotics (some penicillins and virtually all cephalosporins) as well as many aminoglycosides. In the last two decades, particularly virulent strains of "Enterococcus" which are resistant to vancomycin (Vancomycin-resistant enterococcus, or VRE) have emerged in nosocomial infections of hospitalized patients especially in the US. Other developed countries such as the UK have been spared this epidemic, and in 2005, Singapore managed to halt an epidemic of VRE. VRE may be treated with Quinupristin/dalfopristin (Synercid) with response rates of approximately 70%.cite journal |author=Tünger A, Aydemir S, Uluer S, Cilli F |title=In vitro activity of linezolid & quinupristin/dalfopristin against Gram-positive cocci |journal=Indian J Med Res |volume=120 |issue=6 |pages=546–52 |year=2004 |pmid=15654141]

Enterococcal meningitis is a rare complication of neurosurgery. It often requires treatment with intravenous vancomycin; intrathecal vancomycin is often used and it is debatable whether this has any impact on outcome. The removal of any neurological devices is a crucial part of the management of these infections.cite journal |author=Guardado R, Asensi V, Torres JM, "et al" |title=Post-surgical enterococcal meningitis: clinical and epidemiological study of 20 cases |journal=Scand. J. Infect. Dis. |volume=38 |issue=8 |pages=584–8 |year=2006 |pmid=16857599 |doi=10.1080/00365540600606416]

Water quality

In bodies of water, the acceptable level of contamination is very low, for example in the state of Hawaii, with among the strictest tolerances in the United States, the limit for water off its beaches is 7 colony forming units per 100 ml of water, above which the state may post warnings to stay out of the ocean.cite web | title=Clean Water Branch | work=Hawaii State Department of Health | url=http://www.hawaii.gov/health/environmental/water/cleanwater/index.html | accessdate=2007-02-08] In 2004, "Enterococcus spp." took the place of fecal coliform as the new federal standard for water quality at public beaches. It is believed to provide a higher correlation than fecal coliform with many of the human pathogens often found in city sewage.cite journal |author=Jin G, Jeng HW, Bradford H, Englande AJ |title=Comparison of E. coli, enterococci, and fecal coliform as indicators for brackish water quality assessment |journal=Water Environ. Res. |volume=76 |issue=3 |pages=245–55 |year=2004 |pmid=15338696|doi=10.2175/106143004X141807]

References