A Frequency and Molecular Typing Study ofMethicillin-Resistant Staphylococcus aureus

Background and aims: Methicillin-resistant Staphylococcus aureus (MRSA)remains a significant public health problem and treatment chal-lenge. This studywas conducted to determine the frequency, molecular types, and drug resistanceof S. aureus isolated from nasal carriers in two teaching hospitals (Hajar andKashani) in Shahrekord, southwestern Iran.Methods: In this cross-sectional study, ۲۶۲ nasal specimens were obtained fromhealthcare staff. The disk-diffusion method was used to detect MRSA. Nineantibiotic disks were used to determine the antibiotic susceptibility pattern.Staphylococcal cassette chromosome mec (SCCmec) types were identified bythe multiplex polymerase chain reaction (PCR). The data analysis was performedusing Fisher’s exact test with SPSS software.Results: Forty-eight (۱۸.۸%) specimens were identified as S. aureus, of which ۳۰(۱۱.۴۵%) specimens were methicillin resistant. The nasal colonization rate of theMRSA isolates was not associated with age or gender (P > ۰.۰۵). The highestresistance (۳۳%) recorded was to rifampin, and all the isolates were susceptibleto quinupristin-dalfopristin, vancomycin, and linezolid. The SCCmec resultsshowed that ۱۶.۷%, ۶.۷%, ۲۰%, and ۵۶.۶% of MRSA isolates were types I, II, III,and IV, respectively.Conclusions: Nasal isolates of MRSA were prevalent among hospital staff. Thehighest level of resistance was to rifampin, and all the isolates were susceptibleto quinupristin-dalfopristin, vancomycin, and linezolid. SCCmec type ۴ was themost frequent MRSA isolate.

کلیدواژه ها:

Methicillin-Resistant ، Molecular Typing ، Drug Resistance ، Staphylococcus aureus