STAPHYLOCOCCUS CASSETTE CHROMOSOME MEC TYPING OF METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS STRAINS PREVAILING IN HAYATABAD MEDICAL COMPLEX, PESHAWAR

Abstract

Introduction: Methicillin resistance Staphylococcus aureus is a very potential human pathogen, and its significant antibiotic resistance further complicates the management of this pathogen. Methicillin resistance in S. aureus is conferred by the presence of SCCmec elements but there are different types of SCCmec in MRSA which results in the need of typing of SCCmec elements.

Material & Methods: This cross-sectional study was conducted to determine the current antibiotic resistance pattern and prevalence of different types of SCCmec elements in the circulating MRSA at Hayatabad Medical Complex, Peshawar.  A total of 60 non repetitive MRSA isolates collected from pus aspirate and wound swab were enrolled in the study. All the MRSA isolates were tested by disc diffusion method against the ten antibiotics and further subjected to the SCCmec typing through two multiplex PCR reactions. 

Results: Out of the total tested MRSA isolates 80% were resistant to Ciprofloxacin, 63.4% to Erythromycin, 58.4% to Gentamicin, 55.0% to Cotrimoxazole, 51.6% to Tetracycline, 48.4% Fusidic acid, 46.6% to Clindamycin, 35.0% to Doxycycline, while Quinupristin/Dalfopristin and Linezolid kill 100% strains of the MRSA included in the study. SCCmec typing of MRSA isolates showed that prevalence of SCCmec type-III was 3.3% (3/60), types-IV was 58.3% (35/60), and type-V was 38.3% (23/60).

Conclusion: The studied MRSA showed worrisome resistance, but Quinupristin/Dalfopristin and Linezolid kill all the strains of MRSA. The prevalence of SCCmec types IV and V is very high which indicates that the circulating MRSA clone are community associated, because they harbour SCCmec type IV and V.