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. 1995 Jul;33(7):1909–1911. doi: 10.1128/jcm.33.7.1909-1911.1995

Evidence that the National Committee for Clinical Laboratory Standards disk test is less sensitive than the screen plate for detection of low-expression-class methicillin-resistant Staphylococcus aureus.

A M Mackenzie 1, H Richardson 1, R Lannigan 1, D Wood 1
PMCID: PMC228296  PMID: 7665669

Abstract

A low-expression-class methicillin-resistant Staphylococcus aureus strain (strain 9302-2) was sent to 207 laboratories as part of the bacteriology component of the Laboratory Proficiency Testing Program of Ontario. An incorrect (susceptible) result was reported by 16 of 76 (21%) of laboratories that used the National Committee for Clinical Laboratory standards disk test, whereas 1 of 104 laboratories that used other methods reported an incorrect result (P < 0.05). Experiments showed discrepancies in the disk test results given by Mueller-Hinton agars from three manufacturers. We advise that laboratories should use a low expression-class methicillin-resistant S. aureus isolate as a control for the National Committee for Clinical Laboratory Standards disk test.

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Selected References

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