Ability of clinical laboratories to detect antimicrobial agent-resistant enterococci.
To test the ability of clinical laboratories to detect antimicrobial resistance among enterococci, we sent four vancomycin-resistant enterococcal strains and one beta-lactamase-producing enterococcus to all 93 nongovernment, hospital-based clinical laboratories in New Jersey; 76 (82%) participated in the study. Each organism was tested by the laboratory's routine antimicrobial susceptibility testing method. The proportion of laboratories that correctly reported that an isolate was resistant to vancomycin varied according to the resistance level of the isolate: high-level resistance (MIC for Enterococcus faecium = 512 micrograms/ml), 96% of laboratories correct; moderate-level resistance (MIC for E. faecium = 64 micrograms/ml), 27% correct; low-level resistance (MIC for Enterococcus faecalis = 32 micrograms/ml), 16% correct; and intrinsic low-level resistance (MIC for Enterococcus gallinarum = 8 micrograms/ml), 74% correct. The beta-lactamase-producing E. faecalis isolate was identified as resistant to penicillin and ampicillin by 66 and 8% of laboratories, respectively, but only three laboratories recognized that it was a beta-lactamase producer. This survey suggests that many laboratories may fail to detect antimicrobial agent-resistant enterococci.
Tenover
F C
FC
Nosocomial Pathogens Laboratory Branch, Centers for Disease Control and Prevention, Atlanta, Georgia 30333.
Tokars
J
J
Swenson
J
J
Paul
S
S
Spitalny
K
K
Jarvis
W
W
D000668:Ampicillin Resistance; D001431:Bacteriological Techniques; D003951:Diagnostic Errors; D004352:Drug Resistance, Microbial; D016983:Enterococcus / Q000187:drug effects* / Q000302:isolation & purification; D005069:Evaluation Studies as Topic; D006801:Humans; D007755:Laboratories, Hospital; D008826:Microbial Sensitivity Tests; D009515:New Jersey; D010403:Penicillin Resistance; D014640:Vancomycin / Q000494:pharmacology
D014640:Vancomycin