Negin rahmani - Institute for Cancer Research, Shiraz University of Medical Sciences, Shiraz, Iran
amir emami - Shiraz University of Medical Sciences, Burn & Wound Healing Research Center, Microbiology department, Amir-Al-Momenin Burn Hospital, Shiraz, Fars, IRAN
neda Pirbonyeh - Shiraz University of Medical Sciences, Medical School, Bacteriology & Virology department, Shiraz, Fars, IRAN
Fatemeh Javanmardi - Shiraz University of Medical Sciences, Medical School, Bacteriology & Virology department, Shiraz, Fars, IRAN

Background and Aim: The emergence of antibiotic resistance is a serious global threat. Staphylococcus aureus easily develops resistance to new antibiotics and is the leading cause of burn wound infections worldwide. Plasmid-borne Antibiotic Resistance Genes (ARGs) are the agents responsible for the majority of this resistance. In this study, we aimed to assess the prevalence of several plasmid-borne ARGs of S. aureus strains, determine the antibiotic resistance patterns of these strains and evaluate the correlation between the presence of ARGs and resistance to their associated antibiotics in burn patients.Methods: In this cross-sectional study, ۹۳ isolates of S. aureus were isolated from burn patients admitted in Amir-al-Momenin burn hospital affiliated with Shiraz University of Medical Sciences, Iran. These strains were tested for the following ARGs: blaZ, dfrA, ermB, ermC, ileS-۲ (mup), mphBM and msrA. Antibiotic susceptibility was determined by disk diffusion method. The obtained data were analysed using SPSS software.Results: The number (%) of isolates with ARGs in descending order of frequency is as follows: blaZ: ۹۱ (۹۷.۸%), ermC: ۸۷ (۹۳.۵%), dfrA and mphBM: ۸۵ (۹۱.۴%), msrA: ۷۴ (۷۹.۶%), mecA: ۲۹ (۳۱.۲%), ermB: ۲۶ (۲۸%) and ileS: ۲۰ (۲۱.۵%). We found a positive correlation between the presence of mecA and resistance to the following antibiotics: Ciprofloxacin (P=۰.۰۰۰), Clindamycin (P=۰.۰۰۰), Erythromycin (P=۰.۰۰۰), Gentamycin (P=۰.۰۰۰), Cefoxitin (P=۰.۰۰۴), Azithromycin (P=۰.۰۳۴), Rifampin (P=۰.۰۰۲). The lowest and highest antibiotic resistance was observed with Vancomycin (۰%) and Azithromycin (۹۳%), respectively.Conclusion: Although the prevalence of mecA positive S. aureus was relatively low compared with the other burn centers in Iran, the high prevalence of other ARGs and resistance to their associated antibiotics is an alarming finding that requires the attention of physicians as well as health policy makers.

S. aureus; Antibiotic resistance; Burn wound infection.