Quick Review Cards for Medical Laboratory Science

Antibiograms of Gram-Positive Cocci Clinical Microbiology Review 169

ORGANISM SUSCEPTIBILITY ROUTINE SUSCEPTIBILITY TESTING?

Staphylococcus aureus

Group A streptococci

Group B streptococci

Streptococcus pneumoniae

Group D streptococci

Enterococci

Yes

No

No (may be done when isolated from baby)

Yes

Yes

Yes

Significant resistance to multiple antibiotics, including

vancomycin. Usually resistant to penicillin & ampicillin.

Methicillin-resistant S. aureus(MRSA) resistant to all

b-lactams.

Universally susceptible to penicillin, cephalosporins,

vancomycin.

Susceptible to penicillin, cephalosporins, vancomycin.

Increasingly resistant to penicillin & other antibiotics.

Susceptible to vancomycin.

Susceptible to penicillin, vancomycin.

Usually resistant to penicillin & several other commonly

used antibiotics. Most are susceptible to vancomycin, but

vancomycin-resistant enterococci (VRE) are becoming

more common in hospitals.