Characterization of Staphylococcal Cassette Chromosome Mec Elements in Biofilm-producing Staphylococcus Aureus, Isolated from Hospital Infections in Isfahan

Background and Aims: Staphylococcus aureus is one of the important pathogens around the world. The present investigation was carried out to study the distribution of Staphylococcal Cassette Chromosome Mec (SCCmec) types and antibiotic resistance properties in methicillin-resistant Staphylococcus aureus isolated from Isfahan hospitals. Materials and Methods: A total of 250 clinical specimens were collected from three major Isfahan hospitals. The samples were cultured, and biofilm producer isolates were subjected to several polymerase chain reaction methods. The patterns of antibiotic resistance were studied using the disk diffusion method. Results: In the present study, 110 out of 250 samples (44%) were found to be positive for Staphylococcus aureus, and all the isolates produced the biofilm in different levels. The most commonly infected samples were collected from wounds (44.5%). The incidence of mecA, tetK, ermA, ermC, tetM, aacA-D, linA, msrA, vatA, vatC and vatB antibiotic resistance genes were 93.6%, 34.84%, 28.20%, 29.30%, 21.87%, 18.71%, 9.48%, 8.65%, 7.18%, 4.43% and 3.71%, respectively.  The distribution of SCCmec III (42) was found to be the most type out of 103 mec positive strains. Conclusions: In the prsent study, the highest resistance belonged to methicillin (90.2%), erythromycin (89.7%), ciprofloxacin (89.5%) and penicillin (88%) and the lowest resistance was reported for vancomycin (10%) and nitrofurantoin (8%). These infections with these strains require more advanced hospital care with an emerging demand for the novel antibiotics.