Correlation of cefoxitin MICs with the presence of mecA in Staphylococcus spp.
This report describes the results of an 11-laboratory study to determine if a cefoxitin broth microdilution MIC test could predict the presence of mecA in staphylococci. Using breakpoints of < or = 4 microg/ml for mecA-negative and > or = 6 or 8 microg/ml for mecA-positive isolates, sensitivity and specificity based on mecA or presumed mecA for Staphylococcus aureus at 18 h of incubation were 99.7 to 100% in three cation-adjusted Mueller-Hinton broths tested. For coagulase-negative strains at 24 h of incubation, breakpoints of < or = 2 microg/ml for mecA-negative and > or = 4 microg/ml for mecA-positive isolates gave sensitivity and specificity of 94 to 99% and 69 to 80%, respectively.
Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. jms1@cdc.gov
Jana M
JM
Swenson
William B
WB
Brasso
Mary Jane
MJ
Ferraro
Dwight J
DJ
Hardy
Cynthia C
CC
Knapp
David
D
Lonsway
Sigrid
S
McAllister
L Barth
LB
Reller
Helio S
HS
Sader
Dee
D
Shortridge
Robert
R
Skov
Melvin P
MP
Weinstein
Barbara L
BL
Zimmer
Jean B
JB
Patel
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D002440:Cefoxitin / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D046915:Penicillin-Binding Proteins; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013210:Staphylococcus / Q000187:drug effects* / Q000235:genetics
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C487495:MecA protein, Staphylococcus epidermidis; D046915:Penicillin-Binding Proteins; C487789:mecA protein, Staphylococcus aureus; D002440:Cefoxitin