High-level aminoglycoside resistance in enterococci.
In recent years enterococci have been isolated with increasing frequency in association with serious infections. Suitable therapy for empirical treatment can only be chosen on the basis of susceptibility studies. The synergistic effects obtained by the combination of aminoglycosides with penicillin or vancomycin disappear in strains that show high level resistance (HLR) to the former. This highlights the importance of correct identification of the species of Enterococcus (especially Enterococcus faecium, a particularly resistant species), and of studies designed to examine HLR in severe infections. The preferred methods are dilution in solid or liquid medium with 2,000 micrograms of aminoglycoside per ml, or diffusion in solid medium from discs impregnated with 120 micrograms of gentamicin (which also predicts the microorganism's susceptibility to tobramycin and netilmicin) or kanamycin (which also predicts the response to amikacin), and 300 micrograms of streptomycin, for Enterococcus faecalis. The reliability of automated systems for the prediction of HLR to aminoglycosides has yet to be assessed.
Gutiérrez
J
J
Departamento de Microbiologia, Hospital Universitario San Cecilio, Universidad de Granada, Spain.
Hoyos
A
A
Piedrola
G
G
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D016983:Enterococcus / Q000145:classification / Q000187:drug effects*; D005839:Gentamicins / Q000494:pharmacology; D007201:Indicator Dilution Techniques; D007613:Kanamycin Resistance; D008826:Microbial Sensitivity Tests; D013307:Streptomycin / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D005839:Gentamicins; D013307:Streptomycin