Determination of Virulence Factors and Resistance Profile of Methicillin-Resistant Staphylococcus aureus Strains among Different Types of spa, agr, and SCCmec

Abstract

In order to restrict the spread of methicillin-resistant S. aureus (MRSA) in hospitals, it is necessary to characterize isolates rapidly and precisely. The objective of this study was to determine virulence factors and resistance profiles of MRSA strains among spa, agr, and SCCmec types. In total, 55 MRSA isolates were collected from clinical specimens. The MRSA isolates were characterized by antimicrobial susceptibility testing, virulence genes, agr typing, spa typing, and SCCmec typing. According to our findings, all MRSA strains were resistant to cefoxitin; 88% and 86.7% of which were resistant to erythromycin and clindamycin, respectively. Type II agr was predominant with 54.54% frequency. Among 27 different spa types, type t030 was most frequently (25.45%). Most MRSA isolates (63.3%) were SCCmec type III. The pvl and tst genes were found in 25.3% and 32.7% of MRSA isolates, respectively. Among the MRSA strains, ermA, ermB, and ermC were present in 50%, 33.3%, and 57.3% of cases, respectively. In addition, 43 of the 55 MRSA strains (78%) harbored aminoglycoside resistance genes. The results of our study revealed that the MRSA rate in our region is dramatically high. Better infection control guidelines in hospitals, as well as ongoing epidemiological surveillance studies, could be strongly suggested for effective prevention of the spread of MRSA to inpatients.