Peyman Bohlouli
1, Mohammad Reza Nahaei
2*, Safar Farajnia
3, Mojtaba Varshochi
4, Morteza Ghojazadeh
5, Mohammad Akbari Dibavar
2, Javid Sadeghi
21 M.Sc. student, International Branch of Aras, Tabriz University of Medical Sciences, Tabriz, Iran
2 Infectious and Tropical Diseases Research Centre of Tabriz University of Medical Sciences & Department of Microbiology and Laboratory Sciences, Tabriz Branch, Islamic Azad University, Tabriz, Iran
3 Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
4 Infectious and Tropical Diseases Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
5 Liver and Gastrointestinal Diseases Research Center, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
Abstract
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.