Phenotypic Characterization and Antibiotics Combination Approach to Control the Methicillin-resistant Staphylococcus aureus (MRSA) Strains Isolated from the Hospital Derived Fomites

Objective: The emergence of antibiotic resistant Stphylococcus aureus strains have resulted in significant treatment difficulties which have imposed a burden on health care systems and simultaneously intensifying the need for new antimicrobial agents. Therefore, we have designed the study to determine the prevalence of Methicillin-resistant Staphylococcus aureus (MRSA) and their antimicrobial susceptibility pattern along with evaluation of antibiotic combination approach. Material & Methods: Isolation and identification of MRSA was carried out using Mannitol salt agar followed by Baird-Parker Agar and Vojel-Johnson Agar media. Strains were tested for the sensitivity against five β-lactum, two macrolide and one fluoroquinolone class of antibiotic. Further sensitivity was confirmed using 9 diverse- second and third generation antibiotics. MIC value of individual and mixture of antibiotics were measured using Mueller-Hinton broth. Results: Total 10 stains of S. aureus were isolated and characterised using standard biochemical tests. They were identified using on-line identification tool- GIDEON (Global Infectious Disease and Epidemiology Network). Almost 50 % strains were reported having variable reaction against at least one or more antibiotic. By the use of augmentin (30µg), cephotaxime (30µg), ceftriaxone (30µg), cefuroxime (30µg), ciprofloxacin (5µg), clindamycin (2µg), gentamycin (10µg), lincomycin (2µg) and tobramycin (10µg) further susceptibility tesing was carried out which reveals absolute resistant in 70 % of strains, whereas, remeaning strains were seen having variable responses against five antibiotics. However, with comparison to standard antibiotic zone of inhibition, all strains were categorized as a resistant. An individua