Evaluation of the CLSI cefoxitin 30-microg disk-diffusion method for detecting methicillin resistance in staphylococci.
Methicillin susceptibility of 415 staphylococcal isolates from Chinese hospitals was assessed using the CLSI disk-diffusion method with a cefoxitin 30-microg disk in comparison with an oxacillin 1-microg disk. PCR-based detection of mecA was the reference standard. The cefoxitin 30-microg disk performed with almost the same high level of accuracy as the oxacillin 1-microg disk in detecting methicillin resistance in Staphylococcus aureus. For coagulase-negative staphylococci (CoNS), the sensitivity of the cefoxitin 30-microg disk was 90.5%, compared with 83.4% for the oxacillin 1-microg disk. Confirmatory testing of isolates with borderline susceptibility and revision of the cefoxitin breakpoint are proposed in order to categorise CoNS more accurately.
Zhu
L-X
LX
Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing, China.
Zhang
Z-W
ZW
Wang
C
C
Yang
H-W
HW
Zhang
Q
Q
Cheng
J
J
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015373:Bacterial Typing Techniques / Q000379:methods*; D002440:Cefoxitin / Q000494:pharmacology*; D016106:Methicillin Resistance; D010068:Oxacillin / Q000494:pharmacology; D012680:Sensitivity and Specificity; D013210:Staphylococcus / Q000187:drug effects*
D000900:Anti-Bacterial Agents; D002440:Cefoxitin; D010068:Oxacillin