Tabriz University of Medical Sciences Medical Journal of Tabriz University of Medical Sciences 2783-2031 38 4 2016 10 05 Cassette Chromosome mec Typing of Methicillin-Resistant Staphylococcus aureus Isolates Collected from Sina and Imam Reza Hospitals of Tabriz 12 21 EN Peyman Bohlouli Mohammad Reza Nahaei Safar Farajnia Mojtaba Varshochi Morteza Ghojazadeh Mohammad Akbari Dibavar Javid Sadeghi Journal Article 2016 09 24 Backgrounds and Objectives: Methicillin-resistant Staphylococcus aureus is a cause of nosocomial infections leading to high mortality. Since these strains have become prevalent in the world, it is necessary to identify and type them. Materials and Methods: This cross-sectional study was conducted to study a total of 1475 specimens collected from patients of Imam Reza and Sina hospitals of Tabriz in 2012-2013. Using phenotypic tests such as Gram stain, catalase, coagulase, DNase and mannitol fermentation 169 isolates of Staphylococcus aureus and by utilizing methicillin-resistance test 100 MRSA isolates were identified. SCCmec typing was performed by multiplex PCR method and the results were analyzed using chi-square tests using SPSS-18 software. Results: Disc agar diffusion test using cefoxitin disc (30 µg) showed methicillin resistance in 59% of our isolates. mecA and femB genes were identified in all of the MRSA isolates using PCR method. Frequency of SCCmec types and sub-types were as follow: SCCmecIII (77%), SCCmecI (5%), SCCmecIVa (1%), SCCmecIVc (1%), mixed isolates SCCmecIVc-III (1%) and Non typeable isolates (15%). Non typeable isolates recovered in two groups (10% without any band and 5% of multi-bands III-I). In this study, 82% of isolates were HA-MRSA, 3% were CA-MRSA and 15% were Non-typeable. Conclusion: In our S. aureus isolates, the prevalence of methicillin resistance was 59%. The most frequent SCCmec type was SCCmecIII (77%). Our results demonstrated the spread of HA-MRSA isolates in the community and propagating CA-MRSA isolates in the studied hospitals.