Phenotypic and Molecular Characterization of Methicillin-Resistant Clones Carrying the Panton-Valentine Leukocidin Genes Disseminating in Iranian Hospitals.

The spread of Panton-Valentine leukocidin (PVL)-carrying strains in both hospital and the community is a significant worldwide problem. The aim of the study was to investigate the clonal dissemination pattern of PVL-producing strains isolated from hospitalized patients in Tehran, Iran. In this cross-sectional study, 70 PVL-carrying strains were recovered from 240 clinical specimens and characterized by antibiotic susceptibility testing, typing, SCC typing, typing, multilocus sequence typing, and virulence and adhesion gene profiling. All the PVL-carrying strains were confirmed as methicillin-resistant (MRSA) and recovered from wounds (48.6%), blood (25.7%), exudate/pus (11.4%), sputum (8.6%), and body fluid (5.7%) samples. Among the 70 PVL-carrying strains tested, 38 (54.3%) were positive for gene, 27 (38.6%) for , 13 (18.6%) for (A), 13 (18.6%) for (C) 13 (18.6%) for (M) 11 (15.7%) for (A) 10(14.3%) for (B), 9 (12.9%) for , 5 (7.1%) for , and 2 (2.9%) for (B) genes. Five clonal complexes (CC) and nine different clones were detected in this study. The most frequent CC was CC22 (ST22) (42.8%) followed by CC30 (ST30) (21.5%), CC8 (ST8) (17.2%), CC1 (ST772) (11.4%), and CC80 (ST80) (7.1%). In this study, ST22-SCC IV/t852 was the predominant PVL-positive MRSA clone (20%), followed by ST8-SCC IV/t008 (17.2%), ST30-SCC IV/t019 (12.9%), ST22-SCC IV/t790 (11.4%), ST22-SCC IV/t005 (11.4%), ST30-SCC IV/t021 (8.6%), ST80-SCC IV/t044 (7.1%), ST772-SCC V/t657 (7.1%), and ST772-SCC V/t10795 (4.3%). Diversity in clonal types of PVL-carrying MRSA strains in our study supports the need to perform a systematic surveillance of PVL-positive MRSA strains.