Background: Methicillin-resistant Staphylococcus aureus (MRSA) colonization is
considered a major risk factor for nosocomial infections and its decolonization has
reduced these infections. Mupirocin (MUP) is the topical antibiotic of choice for
decolonization. MUP decolonization failure is attributed to MUP resistance. Objective:
The aim of the current study is to assess MUP resistance among MRSA isolates
phenotypically and genotypically. Methodology: Fifty MRSA isolates were identified in
Microbiology Department in the Medical Research Institute hospital, Alexandria
University. Antibiotic susceptibility to different classes of antibiotics by disk diffusion
method was done. MUP minimum inhibitory concentration (MIC) was determined
phenotypically by MUP Ezy MIC™ Strips. MUP resistance was determined genetically
by multiplex PCR detection of mupA and mupB. Results: Of all MRSA isolates, 6%
exhibited high level and none showed low level MUP resistance. Only mupA was
detected in all resistant isolates. Conclusion: Despite low prevalence of MUP
resistance, it is appropriate to test MUP resistance prior nasal decolonization