Enterococcus Flashcards
What is enterococcus?
Formally Group D Streptococcus
Enteric Bacteria
Inherently resistant to many abx
What are the important species of enterococci?
E.Faecalis
E.Faecium
What are the characteristics of Enterococcus?
Gram positive Cocci in short pairs or chains
Alpha, Beta, or gamma hemolytic
PYR Positive
Bile Resistant
What do enterococcal infections cause?
UTI
Endocarditis
Biliary Tree Infection
2nd most common nosocomial pathogen
What are the virulence factors for enterococcus?
Colonization Factors: Aggregation and carb adhesins
Secreted Factors: Cytolysin, pheromone, gelatinase
How is enterococcus transfmitted?
Originates in pt’s bowel flora -> we are the carriers
Contaminated food/water
What is VRE
Vancomycin REsistant Enterococci: Due to Van A, B C genes A: Plasmid B: chromosomal C: intrinsic/chromosomal
How are enterococcal infections treated?
Tx: Linezolid, Tigecycline
Systemic Infections: Ampicillin + Aminoglycoside (synergy)
E.Faecalis: susceptible to pen/amp
E.Faecium: resistant to pen/amp
VRE: Linezolid
What abx are enterococci inherently resistant to?
Cephalosporins
Trimethoprim-sulfa
Aminoglycosides
Dont even test them for these
An organism is isolated from the blood of a 65 year-old male
patient with a diagnosis of probable bacterial endocarditis.
The organism displays streptococcus-like morphology on
gram stain and is catalase-negative. On blood agar the
colonies appear gamma hemolytic and are PYR positive.
Patient was being treated with vancomycin plus an
aminoglycoside with no response. This isolate is likely to be:
A. Streptococcus pyogenes
B. An Enterococcus species
C. Group B Streptococcus
D. A member of the “Streptococcus milleri” group
E. A Staphylococcus species
B
Which species of enterococci is more pathogenic?
E.Faecium
Which species of enterococci is more prevalent?
E.Faecalis
