TY  - JOUR
TI  - Frequency of macrolide resistance gene msrA in clinically isolated erythromycin resistant Staphylococcus aureus strains from a tertiary care setting in Sindh, Pakistan
AU  - Asif, Muhammad
AU  - Hussain, Mushtaq
AU  - Noori, Muhammad Yahya
AU  - Shabbir, Sanya
AU  - Sharafat, Shaheen
JO  - Pakistan Journal of Pharmaceutical Sciences
JA  - Pak. J. Pharm. Sci.
VL  - 39
IS  - 5
SP  - 1552
EP  - 1555
PY  - 2026
DA  - 2026/05
KW  - Drug resistance
KW  - Erythromycin
KW  - Macrolides
KW  - msrA
KW  - Staphylococcus aureus
DO  - 10.36721/PJPS.2026.39.5.REG.12053.1
AB  - Background: The msrA gene encodes an efflux pump protein responsible for macrolide resistance in various bacterial species. Macrolide resistance in Staphylococcus aureus has become an emerging clinical concern, and the prevalence of the msrA efflux pump gene is of clinical importance. Objectives: To determine the frequency of the msrA gene among clinically isolated erythromycin-resistant Staphylococcus aureus strains. Methods: This cross-sectional study was conducted at the Department of Microbiology, Dow Diagnostic Research and Reference Laboratory, Karachi, Pakistan, from January 1, 2018 to January 31, 2019. Forty erythromycin-resistant Staphylococcus aureus isolates were obtained from clinical samples using standard microbiological procedures. Antibiotic susceptibility testing was performed according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Resistant isolates were preserved in Brain Heart Infusion Broth (BHI), and polymerase chain reaction (PCR) was performed to detect the presence of the msrA gene. Results: The frequency of the msrA gene was found to be 70% among erythromycin-resistant Staphylococcus aureus isolates. Conclusion: The findings indicate that the msrA gene is a major contributor to macrolide resistance in locally isolated clinical strains. The use of efflux pump inhibitors alongside macrolide antibiotics may improve bacterial sensitivity and potentially enhance clinical outcomes.
ER  -