Prevalence, Diversity, and Antimicrobial Susceptibility Profiles ofMethicillin-Resistant Staphylococcus aureus Among Patients withDiabetic Foot Infections in a Referral Hospital in Tehran, Iran

Abstract

Background: The increasing incidence of methicillin-resistant Staphylococcus aureus (MRSA) poses a significant challenge in thetreatment of diabetic foot infections (DFIs).Objectives: This study aimed to investigate the prevalence and diversity of clonal groups of MRSA strains isolated from patientswith DFIs in a major referral hospital in Tehran. Methods: We determined the prevalence, diversity, and antibiotic susceptibility profiles of MRSA isolated from patients withDFIs attending a referral hospital in Tehran, Iran, during 2019 - 2020. Staphylococcal cassette chromosome mec (SCCmec) typing,ccr typing, PhP typing, and detection of the Panton-Valentine Leukocidin (pvl) gene were performed to explore the diversity ofthe strains. Antibiotic susceptibility profiles of the strains were determined using the disk diffusion method and brothmicrodilution assay. Results: Of the 238 S. aureus strains isolated, 73 were identified as MRSA. The highest antibiotic resistance was observed againstciprofloxacin (86), followed by kanamycin and tobramycin (84). Additionally, 49 of the strains exhibited high-level oxacillinresistance (MIC >= 256 mu g/mL). SCCmec type III and type 3 ccr were detected in 86 of the strains, classifying them as hospital-acquired (HA)-MRSA. PhP typing revealed the presence of 8 common types (CTs) and 11 single types (STs), with CT2 comprising 41of the strains. Conclusions: Our data suggest that MRSA strains isolated from DFIs in this region are diverse and resistant to clinicallyimportant antibiotics. Diabetic patients can serve as a reservoir for the dissemination of these bacteria between community andclinical environments.