Editing Enterococcus (section)

== Physiology and classification ==
Enterococci are [[facultative anaerobic organism]]s, i.e., they are capable of [[cellular respiration]] in both oxygen-rich and oxygen-poor environments.<ref name=Fischetti_2000>{{cite book | veditors = Fischetti VA, Novick RP, Ferretti JJ, Portnoy DA, Rood JI | title = Gram-Positive Pathogens | publisher = ASM Press | year = 2000 | isbn = 1-55581-166-3}}</ref> Though they are not capable of forming [[spore]]s, enterococci are tolerant of a wide range of environmental conditions: extreme temperature (10–45&nbsp;°C), [[pH]] (4.6–9.9), and high [[sodium chloride]] concentrations.<ref name=Fisher>{{cite journal | vauthors = Fisher K, Phillips C | title = The ecology, epidemiology and virulence of Enterococcus | journal = Microbiology | volume = 155 | issue = Pt 6 | pages = 1749–1757 | date = June 2009 | pmid = 19383684 | doi = 10.1099/mic.0.026385-0 | doi-access = free }}</ref>

Enterococci exhibit variable [[Hemolysis (microbiology)|hemolysis]] on [[blood agar]]. Differences occur between species, and between strains of species. More [[Virulence|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.<ref>{{cite journal | vauthors = Semedo T, Almeida Santos M, Martins P, Silva Lopes MF, Figueiredo Marques JJ, Tenreiro R, Barreto Crespo MT | title = Comparative study using type strains and clinical and food isolates to examine hemolytic activity and occurrence of the cyl operon in enterococci | journal = Journal of Clinical Microbiology | volume = 41 | issue = 6 | pages = 2569–2576 | date = June 2003 | pmid = 12791882 | pmc = 156526 | doi = 10.1128/jcm.41.6.2569-2576.2003 }}</ref>

=== History ===

Members of the genus ''Enterococcus'' (from [[Greek language|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.<ref>{{cite journal |vauthors=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. Syst. Bacteriol.| year= 1984 | volume= 34 | pages= 31–34 | doi = 10.1099/00207713-34-1-31 | doi-access= free }}</ref>