Detection Of Methicillin Resistant Staphylococcus Aureus (Mrsa) In Tertiary Care Hospital Of North Karnataka

Abstract

Introduction : Methicillin resistant Staphylococcus aureus strains emerged after the introduction of methicillin. It leads to various type of skin infections, osteoarthritis and respiratory tract infections and other infections in humans. The objectives of the study included 1.To evaluate different screening tests for detection of Methicillin resistant Staphylococcus aureus . (MRSA) 2.To know the antimicrobial profile of MRSA strains. 3.To detect of mec A gene by molecular methods( PCR) and Molecular identification of MRSA by detection of SCCmec .4.To compare different phenotypic methods with PCR for identification of MRSA. Methods: The current study was conducted in Microbiology Department, SBMPMCHRC, Vijayapur.A total of 383 S.aureus were identified and antimicrobial susceptibility pattern studied for three years period. Stastistical analysis: Values were expressed in terms of Mean ± SD. Analysis was done by using SPSS software version 16. MRSA were detected byThe Cefoxitin Disc Diffusion Test and The Oxacillin Disk Diffusion Method. Genotypic detection of MRSA was done by identification of mec A gene by PCR . Molecular characterisation of MRSA isolates were carried out by detection of various staphylococcal cassette chromosome mec (SCCmec) by Multiplex PCR. Results: The current study revealed the prevalence of MRSA in the tertiary care center in this part of India is very high(48.6%.). The prevalence of MRSA was more prevalent in males. More number of MRSA were from pus samples (76%). Higher rate of MRSA isolates were from department of Surgery (56.5%). Linezolid (89% sensitive), tetracycline (86%) vancomycin (83%) showed better results against MRSA. Out of 186 isolates of MRSA, oxacillin and cefoxitin detected 80%, 96% MRSA respectively. Results of cefoxitin disc diffusion by cefoxitin is in agreement with the PCR for identification of mecA gene.. We found a higher number of multidrug-resistant MRSA (76.8%) in our hospital. This study shows that the prevalent MRSA strains in Vijayapur are SCCmec-III and SCCmec-II. Conclusion: In the current study, the prevalence of MRSA in the tertiary hospital in this part of India is very high. Therefore, it is mandatory to choose suitable antibiotics with respect to their antimicrobial pattern for treating the infections .Results of disc diffusion test by cefoxitin is in agreement with mecA gene detection by PCR, and therefore the disc diffusion test by cefoxitin is ideal for detection of MRSA and the test can be better alternative to PCR for detection of MRSA in resource poor settings. We found a higher number of multidrug-resistant MRSA in our hospital. If we look into the Indian setting , it seems the burden drug resistant-MRSA is increasing over time. This study shows that the prevalent MRSA strains in Vijayapur are SCCmec-III and SCCmec-II.