ENTEROCOCCUS

'''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.^[1]
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. Gram-Positive Pathogens, Fischetti VA; Novick RP; Ferretti JJ; Portnoy DA; Rood JI (editors), , , ASM Press, 2000, ISBN 1-55581-166-3 They typically exhibit gamma-hemolysis on sheep's blood agar.

Contents

Pathology

Water quality

References

Pathology

Important clinical infections caused by ''Enterococcus'' include urinary tract infections, bacteremia, bacterial endocarditis, diverticulitis, and meningitis. Sherris Medical Microbiology, Ryan KJ, Ray CG (editors), , , McGraw Hill, 2004, Sensitive strains of these bacteria can be treated with ampicillin and vancomycin. Microbiology of the Circulatory System. ''in:'' Baron's Medical Microbiology ''(Baron S ''et al'', eds.), Pelletier LL Jr., , , Univ of Texas Medical Branch, 1996,
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%. In vitro activity of linezolid & quinupristin/dalfopristin against Gram-positive cocci, Tünger A, Aydemir S, Uluer S, Cilli F, , , Indian J Med Res, 2004
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. Post-surgical enterococcal meningitis: clinical and epidemiological study of 20 cases, Guardado R, Asensi V, Torres JM, ''et al'', , , Scand. J. Infect. Dis., 2006

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. Clean Water Branch 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 sewage. Comparison of E. coli, enterococci, and fecal coliform as indicators for brackish water quality assessment, Jin G, Jeng HW, Bradford H, Englande AJ, , , Water Environ. Res., 2004

References

1. Transfer of ''Streptococcus faecalis'' and ''Streptococcus faecium'' to the genus ''Enterococcus'' nom. rev. as ''Enterococcus faecalis'' comb. nov. and ''Enterococcus faecium'' comb. nov., Schleifer KH; Kilpper-Balz R, , , Int. J. Sys. Bacteriol., 1984