MINIMUM INHIBITORY CONCENTRATION LEVELS OF MUPIROCIN BY E-TEST AMONG STAPHYLOCOCCUS AUREUS ISOLATES AND THEIR ANTIMICROBIAL SUSCEPTIBILITY PATTERN

Abstract

Objective: This study was done to evaluate the susceptibility of Staphylococcus aureus to mupirocin and to determine the antimicrobial susceptibility pattern of Staphylococcus aureus among various clinical isolates. Methods: All the consecutive, non-duplicative Staphylococcus aureus isolates collected during the year 2020 were subjected to the disk diffusion method to evaluate the antimicrobial susceptibility pattern and were stocked. Mupirocin susceptibility for all stocked Staphylococcus aureus was detected by Minimal inhibitory concentration (MIC) determination by Epsilometer test (E-test). Results: The total number of Staphylococcus aureus was 52. The maximum number of Staphylococcus aureus was isolated from pus sample 40 (76.9%). Among the 52 isolates, 26 (50%) were found to be methicillin-resistant Staphylococcus aureus (MRSA). All the isolates were susceptible to tetracycline (100%), vancomycin (100%), teicoplanin (100%), and linezolid (100%). By E-test, the overall prevalence of mupirocin resistance was 63.5%. Low-level Mupirocin resistance (MupRL) of 8-256 µg/ml was 59.6% and high-level mupirocin resistance (MupRH) of ≥512 µg/ml was 3.9%. Conclusion: The present study shows a high prevalence of mupirocin resistance (63.5%) which is a serious concern. Therefore, indiscriminate use of topical mupirocin in carriers is not advisable. It may be recommended only in case of an outbreak of skin and soft tissue infection attributed to Staphylococcus aureus.