Detection of Methicillin-Resistance Gene in Staphylococcus aureus Isolated from TraditionalWhite Cheese in Iran

Background & Aims of the Study: Methicillin-resistant staphylococcus aureus (MRSA) isconsidered as a major pathogen in public health concern. The objectives of this study wereto firstly determine antibiotic sensitivity among Staphylococcus aureus isolated fromtraditional Iranian white cheese during 2015 from Hamedan province of Iran; and secondlyto estimate the presence of methicillin-resistant S. aureus.Materials &Methods: This cross-sectional study was done by collecting 120 Iranian whitecheeses (traditional and industrial) which were available in different markets; and tested forthe presence of S. aureus by culture methods. The obtained isolates were subjected to discdiffusion antimicrobial susceptibility tests followed by PCR detection of the mecA gene.Results: Out of 120 examined cheese samples, 19 samples (31.67%) were contaminatedwith S. aureus. The highest rate of antibiotic resistance was observed for penicillin, as all ofthe 19 isolates (100%) were found to be resistant to this antibiotic using disk diffusionmethod. Three out of 19 S. aureus isolates (15.7%) were phenotypically resistant tomethicillin (disk diffusion), while 4 (21.05%) of them were genotypically confirmed asMRSA strains. Furthermore, none of the isolates were found resistant to vancomycin.Conclusion: The results of the study confirm the presence of methicillin resistant strains ofS. aureus in Iranian white cheese. It should be considered to constitute a potential healthrisk for consumers, suggesting usage of more stringent hygiene measures.