Use of the E test for methicillin sensitivity testing.
Performance of the E test for methicillin sensitivity testing was investigated using 21 methicillin-resistant and 28 methicillin-sensitive staphylococci. Thirty of the strains had previously given equivocal results with a strip diffusion method. The E test performed well with Mueller-Hinton agar plates incubated at 30 degrees C for 24 h but only after supplementation with 5% NaCl. Testing on agar without salt was necessary for the recognition of methicillin resistance in one strain. We recommend a breakpoint of 4 mg/L and heavy inocula. The E test can be controlled by testing a control strain on the same plate.
Bignardi
G E
GE
Microbiology Department, St Mary's Hospital, London, UK.
Riley
U
U
Easmon
C S
CS
D003470:Culture Media; D004058:Diffusion; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests / Q000379:methods / Q000592:standards; D011934:Reagent Strips; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D001618:beta-Lactamases / Q000096:biosynthesis
D003470:Culture Media; D011934:Reagent Strips; D001618:beta-Lactamases