Prevalence of Mupirocin Resistant Staphylococcus aureus Isolates Among Patients Admitted to a Tertiary Care Hospital

Background: For the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections and decolonization of MRSA carriers, the use of mupirocin a topical antibiotic is increasing day by day. Aim: The present study was carried out to determine the prevalence rate of high-level and low-level mupirocin resistant MRSA isolates among patients admitted to a tertiary care hospital. Materials and Methods: This is a prospective study carried out on MRSA isolated from the various clinical specimens from outpatient and inpatient departments during period of one year. A total of 82 MRSA isolates were recovered from 6468 different clinical specimens. Mupirocin resistant MRSA was detected by two different methods: Epsilometer test (E-test) and agar dilution method. D-shaped zone test (D-zone test) was also performed for determination of inducible clindamycin resistance in MRSA isolates. Results: Out of 82 non-duplicate MRSA isolates mupirocin resistance were found in 15 (18.3%) isolates by both E-test and agar dilution method. Of these 15 mupirocin resistant, 8 (53.3%) isolates were high-level resistant (MuH) and 7 (46.7%) isolates were low-level resistant (MuL). Four isolates were D-zone test positive showing simultaneous inducible clindamycin resistance among mupirocin resistant MRSA isolates. Conclusion: Higher prevalence of both high-level and low-level of mupirocin resistant MRSA was observed in patient from the population. It is advisable to perform routine test to detect MRSA colonization among health care workers and nasal decolonization to prevent spread of MRSA infections among hospitalized patients.