First report of methicillin-resistant Staphylococcus aureus carrying the mecC gene in human samples from Iran: prevalence and molecular characteristics

There is a lack of information concerning mecC clinical methicillin-resistant Staphylococcus aureus (MRSA) strains throughout the world. In the present survey, 345 MRSA strains were characterized by antimicrobial susceptibility testing and staphylococcal cassette chromosome mec element (SCCmec) typing. mecC-positive MRSA isolates were characterized by study of biofilm formability, adhesion and virulence analysis, multilocus sequence typing, accessory gene regulator (agr) typing, S. aureus protein A locus (spa) typing and staphylocoagulase typing. The present study found ten SCCmec types, with the majority being SCCmec type III (38.3%). The presence of mecC was confirmed in three isolates from skin wounds (two isolates) and burn wounds (one isolate). All the mecC-positive isolates carried SCCmec XI and belonged to coa type III. Molecular typing showed that these isolates belonged to clonal complex/ST130-spa type t843-agr type III (two isolates) and clonal complex/ST599-spa type 5930-agr type I. The presence of SCCmec type IV confirms the hypothesis of extensive infiltration from the community to the hospital. Detection of MRSA isolates harbouring the mecC gene highlights the need to perform routine detection methods and molecular investigations in order to identify these emerging strains and limit their transfer in hospitals and communities.