Genotypic Characterization of Clinical Isolates of from Pakistan

In this study, we compared pulsed-field gel electrophoretic (PFGE), multilocus sequence typing (MLST), Staphylococcal cassette chromosome (SCC), typing, and virulence gene profiles of 19 Panton-Valentine leucocidin (PVL)-positive, multidrug-, and methicillin-resistant clinical (MRSA) isolates obtained from a hospital intensive care unit in Pakistan. The isolates exhibited 10 pulsotypes, contained eight adhesin genes ( and ), 10 toxin genes ( and ), and two other virulence genes () that were commonly present in all isolates. The -typing indicated seven known types (t030, t064, t138, t314, t987, t1509, and t5414) and three novel types. MLST analysis indicated eight ST types (ST8, ST15, ST30, ST239, ST291, ST503, ST772, and ST1413). All isolates belonged to the group 1. Most of the isolates possessed SCC type III, but some isolates had it in combination with types SCC IV and V. The presence of multidrug-resistant MRSA isolates in Pakistan indicates poor hygienic conditions, overuse of antibiotics, and a lack of rational antibiotic therapy that have led to the evolution and development of hypervirulent MRSA clones. The study warrants development of a robust epidemiological screening program and adoption of effective measures to stop their spread in hospitals and the community.