Aerobic Gram-Positive Cocci: Enterococci

Question 1

1. Describe the reservoirs of the enterococci.

Answer 1

soil, food, water and as normal flora of animals, birds and humans; E. faecalis and E. facium are normal flora of the GI and female GU tract

Question 2

1. How are enterococci transmitted.

Answer 2

endogenous strains gaining access to sterile sites
hardy organism that survives on surfaces
person to person or healthcare worker transmission

Question 3

3. Discuss the risk factors associated with enterococcal infections.

Answer 3

exposure to invasive devices, esp catheters
prolonged hospitalization
prolonged use of broad spectrum antibiotics
surgery esp. GI or cardiothoracic
age >60 and major underlying disease

Question 4

2. Describe the major enteococcal disease and any significant virulence factors.

Answer 4

combination of adhesions, bacteriocins that inhibit competing flora and inherent and acquired resistance to many commonly used antibiotics

causes endocarditis, UTI, bacteremia and surgical wound/intra-abdominal abscesses (polymicrobial)

Question 5

4. Explain the Gram stain reaction and lab tests used to identify enterococci.

Answer 5

microscopy: gram positive cocci in singles, pairs and short chains
culture: small cream white colonies, a, B or non hemolytic

Question 6

5. Discuss how enterococci infection can be prevented.

Answer 6

reduce antibiotic pressure, restrict broad spectrum antimircrobials, limit intravascular devices and infection control prevent nosocomial spread

Question 7

5. Discuss how enterococci infection can be treated.

Answer 7

ampicilin or amoxicillin if susceptible
penicillin plus gentamicin for endocarditis
vancomycin if susceptible, if resistant linezolid, daptomycin or quinapristin-dalfopristin

Question 8

Describe the class of entercocci.

Answer 8

they are a catalase negative aerobic Gram positive cocci recognized as a common human pathogen