The First Report of Prevalence of Class 1-3 Integrons in Clinical Isolates of Staphylococcus aureus in Southwestern Iran: A Multicenter Study

Abstract

Background: Staphylococcus aureus is one of the main causes of a wide range of nosocomial infections, like the infection of the skin and soft tissue. Objectives: The present study aimed to investigate the occurrence of antibiotic resistance and the presence of class 1-3 integrons in S. aureus strains isolated from hospitalized patients. Methods: This cross-sectional study was carried out during six months in two major hospitals in southwestern Iran. Totally, 134 isolates of S. aureus were identified by phenotypic and molecular methods. A disk diffusion method was used to determine the antibiotic resistance pattern of S. aureus isolates. The detection of integron-encoding genes was performed by the PCR method. Results: Based on antibiotic susceptibility testing, 58 (43.2%) of 134 isolates of S. aureus were reported as methicillin-resistant S. aureus (MRSA) using cefoxitin disc diffusion and mecA gene detection. The highest resistance was seen to tetracycline (48.5%). The results were analyzed by the chi-square test and there was a significant difference (P value < 0.05) between antibiotic resistance in methicillin-sensitive S. aureus (MSSA) isolates. Molecular analysis showed that 53 (39.6%), 5 (3.7%), and none of the isolates were positive for class 1, 2, and 3 integrons, respectively. Conclusions: The results indicated the remarkable rate of class 1 integrons in the clinical isolates of S. aureus in our region and the importance of investigating the prevalence of antibiotic resistance among them. However, these data alone cannot confirm the association between integrons and the presence of antibiotic resistance genes.