Molecular epidemiology of clinical isolates of methicillin-resistant Staphylococcus aureus by multilocus sequence typing in northwestern (Tabriz) and southern (Kerman) of Iran: The emergence of MRSA ST4848-SCCmec III

Methicillin-resistant Staphylococcus aureus is an intrusive human pathogen causing community- and hospital-acquired infections worldwide. The purpose of this study was to investigate the molecular characteristics of MRSA isolates recovered from hospitalized patients in Tabriz and Kerman cities in Iran. A total of 111 MRSA isolates were collected and their patterns of antimicrobial resistance were determined utilizing the disk diffusion method. Minimum inhibitory concentration for vancomycin was determined by E. test on Mueller-Hinton agar plates. nuc and mecA genes were detected by PCR and SCCmec and MLST typing of the isolates were carried out. According to the results, the MRSA prevalence was 40.8% in Tabriz and 57.1% in Kerman. All MRSA isolates were sensitive to vancomycin and linezolid. The rate of multi drug resistance (MDR) was 68.2% in Tabriz and 56.6% in Kerman. 29 (56.86%) and 33 (55%) of MRSA isolates were recorded positive for SCCmec type III in Tabriz and Kerman, respectively. A total of 6 distinct clonal complexes (CC) were identified for MRSA isolates in 9 different sequence types (STs). ST4848 belonging to CC6 and ST859 belonging to CC88 were the predominant types in Tabriz (45.09%) and Kerman (43.33%). The results of the present study bolster the requirement for more MRSA isolates surveillance research to identify potential new MRSA clones and thus more effective infection control.