Isolation and antimicrobial susceptibility pattern of methicillin resistant and methicillin sensitive staphylococcus aureus

To find out frequency and antibiotic sensitivity pattern of methicillin resistant and methicillin sensitive staphylococcus aurues. Descriptive study. Microbiology section of Department of Pathology in National Institute Of Child Health Karachi, from March 2008 to April 2009. All the clinical samples received in laboratory were processed. All staphylococcus aureus isolates were then identified by conventional method. The isolates were tested by the modified Kirby Baur disc diffusion method and results were interpreted as outlined by National Committee for Clinical Laboratory Standard criteria. Eighty seven isolates of staphylococcus aureus were recovered from various clinical samples. Sixty six [75.86%] were isolated from various swabs and 21[24.13%] from blood. Twenty isolates [22.9%] were methicillin resistant. In this group high resistant was found to cloxacillin [100%], cephradine [100%], co-trimoxazole [95%], erythromycin [70%], chloromycetin [65%], gentamicin [55%] and low resistance was observed to ciprofloxacin [30%]. In MSSA 0% resistance was seen to meropenem, ciprofloxacin and chloromycetin and high resistance found to co-trimoxazole [98.5%] and pencillin [73.13%]. Low resistance was also observed with amoxiclav [20.89%]. Both MRSA and MSSA were 100% sensitive to vancomycin. In this study high resistance pattern to non b-lactam antibiotic was found in MRSA leaving restricted choice for the treatment. Good hygiene practices, infection control and emphasis on hand washing etc may slow down the process of resistance