Infection control guidelines

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Canada Communicable Disease Report - Supplement
Volume: 23S8
December 1997

Preventing the Spread of Vancomycin-Resistant Enterococci (VRE) in Canada

Microbiology of Enterococci

For many years, enterococci were considered relatively harmless avirulent flora with little potential for human infection. They are found as normal commensal flora of the gastrointestinal tract in 95% of healthy individuals and as non-pathogenic colonizing flora in the vagina, oral cavity, perineal area, hepatobiliary tract, and upper respiratory tract^(11-14). Open wounds and decubitus ulcers may act as reservoirs for enterococci⁽¹²⁾. The most commonly encountered species include Enterococcus faecalis (E. faecalis) and E. faecium; those encountered less frequently are E. avium, E. durans, E. gallinarum, E. casseliflavus and others (Table 1). E. faecalis is found in large concentrations of 10⁵-10⁷ colony-forming units (CFU)/g of faeces in the vast majority of humans, and the remaining enterococci are found in smaller amounts⁽¹¹⁾. Enterococci are hardy organisms and are able to survive on environmental surfaces for extended periods. Several studies have found multi-resistant strains of enterococci on various objects in the patient's environment, including bed rails, night tables, curtains, bathroom sinks, toilet rings, electronic thermometers, and other patient-care equipment^(15-19).

Table 1 Distribution of Enterococcus Species in Clinical Isolates and Stool
Body Sites	# of Clinical Samples	*E. faecalis*	*E. faecium*	*E. casseliflavus*	*E. gallinarum*	*E. avium*	*E. raffinosus*
Urine	284	93.7%	5.3%	0.7%	0	0	0.3%
Blood and catheter	26	53.8%	42.3%	3.8%	0	0	0
Deep abscess	110	72.7%	22.7%	0.9%	1.8%	0.9%	0
Wounds and mucous membranes	132	90.9%	6.8%	0	0.8%	0	0
Resp. tract (ICU)	22	50.0%	45.5%	0	0	0	4.5%
TOTAL	574	85.5%	12.1%	0.7%	0.5%	0.2%	0.4%
Stool	-	-	-	-	-	-	-
Hospitalized patients	115	36.0%	39.3%	9.3%	11.3%	15.3%	0.6%
Healthy individuals	95	47.0%	55.0%	13.0%	4.0%	8.0%	1.0%
TOTAL	210	40.5%	45.6%	10.5%	8.4%	12.4%	0.8%
Adapted from Blaimont B, Charlier J, Wauters G. Comparative distribution of Enterococcus* species in faeces and clinical samples*. Microbial Ecology in Health and Disease 1995;8:87-92.

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	Last Updated: 2002-11-08		Important Notices