Methicillin-resistant (MRSA) are important nosocomial pathogens. Diseases caused by these resistant bacteria frequently are serious and there is a need to control the spread of epidemic MRSA clones in hospitals. However, detection is complicated by the fact that expression of the resistance is variable and, commonly, heterogeneous within strains. The reliability of several tests recommended to discriminate heterogeneous MRSA isolates from borderline-resistant and susceptible strains was evaluated. Screening for growth on agar with methicillin 25 mg/L was the only method that detected all MRSA strains tested, but screening on agar with methicillin 10 mg/L or oxacillin 6 mg/L detected all but one of 10 heterogeneously resistant strains tested. None of the borderline-resistant nor any truly susceptible staphylococci tested grew on any of these screening plates.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error