POTENT IN-VITRO BACTERICIDAL ACTIVITY OF POLYMYXIN-B AGAINST METHICILLIN-RESISTANT STAPHYLOCOCCUS-AUREUS (MRSA)

Eradication of methicillin-resistant Staphylococcus aureus (MRSA) carr ied by inpatients or healthy hospital personnel by topical use of anti biotics is an important step for preventing outbreak of MRSA nosocomia l infection. In the screening of the antibiotic best suited for this p urpose, we have found that polymyxin B, a commonly used antibiotic for gram-negative infection, had an unexpected strong cytokilling activit y towards MRSA clinical strains, which was more potent than that of va ncomycin or gentamicin. The data suggested that polymyxin B could be a n antibiotic of choice in the treatment of topical carriage of or infe ction caused by MRSA.