Determining the Antibiotic Resistance of Staphylococcus aureus Strains Isolated from Patients Hospitalized in Zahedan, Southeastern Iran

Background & Objective: Staphylococcus aureus is one of the most important public health risks as it causes many forms of infection. Treatment options for infections caused by this pathogen are limited due to the development of resistance to commonly used antibiotics. This study aimed to investigate the antibiotic resistance patterns in Staphylococcus aureus strains.  Materials & Methods: In this cross-sectional study conducted between ۲۰۲۰ and ۲۰۲۳, ۳۴۸ Staphylococcus aureus specimens were isolated from clinical samples at Aliebne Abitaleb Hospital in Zahedan, Iran. Following the identification of the strains, their antibiotic resistance to eight antibiotics was assessed by the disk diffusion method based on Clinical Laboratory Standard Institute ۲۰۲۲, and the MRSA isolates were screened. Additionally, Vancomycin's MIC was evaluated using the E-test. Statistical analysis was conducted using the chi-square test using SPSS, version ۱۶ (IBM SPSS, Armonk, NY, USA).   Results: Of the ۳۴۸ isolated S. aureus strains (۱۷۱ from males and ۱۷۷ from females), ۱۶۳ (۵۰%) were from blood cultures, and ۵۳ (۱۵.۲%) were from tracheal samples. The strains showed the highest resistance to erythromycin (۷۷.۹%) and penicillin (۱۰۰%). The samples had the lowest resistance to cotrimoxazole (۳۶.۲%) and nitrofurantoin (۲۹.۶%). Additionally, all strains were susceptible to vancomycin. In this study, ۷۶% and ۳۰% of the examined strains could be classified as MDR and XDR, respectively. There was no significant association between age, gender, and MRSA infection (P > ۰.۰۵).   Conclusion: In this study, cotrimoxazole showed considerable activity against MRSA strains. Moreover, since all isolates were susceptible to vancomycin, this antibiotic could be the primary treatment choice. The high prevalence of MDR strains is a significant cause for concern.

Keywords:

Antibiotic resistance , Staphylococcus aureus , MRSA