1. Medical Microbiology
Chapter 24
Enterococcus

2. Enterococcus Entero- coccus- Originally classified as Group D strep
2 important species:
Enterococcus faecalis
Enterococcus faecium

3. Physiology and Structure
Gram + cocci in pairs and short chains
Catalase -, fermentation
Tolerant to high salt concentrations and bile salts
Figure

5. Pathogenesis Commensal organisms
Broad range multi-drug antibiotic resistance
Inherent resistance
Acquired resistance
No single potent virulence factor: Colonization and secreted factors

6. Epidemiology Inhabit the intestines of humans and animals
E. faecalis colonize the large intestine (107 organisms per gram of feces) and urinary tract
E. faecium colonize similar sites in lesser numbers
Most infections originate from an intestinal site
Transmission also seen person-to-person and through consumption of contaminated food

7. Clinical diseases Risk factors for enterococcal infections:
Urinary or intravascular catheterization
Long-term hospitalization with broad-spectrum antibiotics
~10% of all nosocomial infections
Important life-threatening nosocomial infections are caused by Vancomycin Resistant Enterococci (VRE)
35-50% mortality rate
Urinary tract infections
Peritonitis
Endocarditis (5-15% of all cases)
Bacteremia
Wound infections and intrabdominal abscesses

9. Treatment, Prevention, and Control
Antibiotic resistance makes treatment difficult
25% resistance to the aminoglycoside
50% resistance to ampicillin
20% resistance to vancomycin
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