Enterococcus: Difference between revisions

Revision as of 17:35, 19 July 2022

Genus of facultative anaerobic, non-spore-forming, alpha- or gamma-hemolytic, catalase negative, Gram-positive cocci
Grows on bile esculin agar
PYR positive
Most are Lancefield group D
Commensal gut flora
Increasing antibiotic resistance

E. faecalis
- More common (90-95%)
- More commonly genitourinary source
- More susceptible to antibiotics
E. faecium
- Less common (5-10%)
- More commonly gastrointestinal source
- Less susceptible to antibiotics
- Most common VRE
E. gallinarum
E. casseliflavus
E. hirae, a rare zoonotic pathogen from chickens that can cause bacteremia and endocarditis

Vancomycin binds to d-Ala-d-Ala pentapeptids, interfering with cell wall synthesis
VanA: most common. Mutation to d-Ala-d-Lac, leading to high resistance to glycopeptides.
VanB: more common in E. faecium in Australia
VanC: chromosomal resistance on E. gallinarum and E. casseliflavus

Vancomycin is usually reliable (except for E. gallinarum and E. casseliflavus)
Ampicillin is preferred for susceptible strains
Inherent resistance to cephalosporins
Resistant to ertapenem, but ampicillin-susceptible strains are often susceptible to imipenem and (less reliably) to meropenem

@@ Line 38: / Line 38: @@
 * [[Ampicillin]] is preferred for susceptible strains
 * Inherent resistance to [[cephalosporins]]
-* Resistant to [[ertapenem]], but ampicillin-susceptible strains are often susceptible to [[imipenem]] and (somewhat) [[meropenem]]
+* Resistant to [[ertapenem]], but ampicillin-susceptible strains are often susceptible to [[imipenem]] and (less reliably) to [[meropenem]]
 ===VRE===