Drug Resistance Pattern in Methicillin-Resistant Staphylococcus Aureus (MRSA) Isolates from Lahore, Pakistan

Background: Methicillin resistant Staphylococcus aureus (MRSA) infections are of great risk to health because they are resistant to most common antibiotics and affixed to hospital acquired and community acquired infections. An evaluation of the antimicrobial resistance patterns of MRSA isolates from blood samples collected in Lahore, Pakistan is performed and prevalence as well as susceptibility trends for MRSA are reported. Objective: The purpose of this study was to determine the drug resistance patterns of MRSA isolates and assess their susceptibility to different agents, both beta lactam and non-beta lactam. Methods: A total of 103 fresh blood sample specimens were investigated using the standard protocols. Colonies were cultured on blood agar plates and Gram stained and the following biochemical tests (catalase and coagulase tests) for the identification of S. aureus were performed. Kirby Bauer method was used for antimicrobial susceptibility testing on Muller Hinton agar using antibiotic discs for ciprofloxacin, clindamycin, piperacillin/tazobactam, gentamicin, linezolid, penicillin, teicoplanin, vancomycin, and cefoxitin. Results: Of 103 blood samples of MRSA, 30 had growths of MRSA. The results indicated that all MRSA isolates were resistant to cefoxitin and penicillin with 100% beta lactam resistance. On the other hand, vancomycin, teicoplanin and linezolid showed 100% susceptibility, which makes them good therapeutic options. In this study, resistance rates for clindamycin, tazobactam and gentamicin were found to be 33.3%, 23.3% and 26.7%, respectively. The resistance rate of ciprofloxacin was 63.3%. Conclusions: Beta lactam antibiotics resistance of MRSA isolates of Lahore are very high therefore alternative agents like vancomycin, teicoplanin and linezolid are used. Too often, MRSA is treated as a highly primitive bacteria, which has it wrong; these findings highlight the need for more surveillance, routine testing and antibiotics judiciously.”