Al Ameen Journal of Medical Sciences (Apr 2023)
Prevalence and Molecular Characterization of MRSA Isolates from Pus and Blood Samples with Special Reference to MecA and ErmA Gene at a Tertiary care in Kanpur
Abstract
Background: Methicillin-resistant staphylococci are now recognized as a major cause of infectious diseases, particularly in hospitals. Molecular epidemiology is important for prevention and control of infection. This study is used to find out the prevalence and gene causing resistance mechanisms for MRSA isolates. Aim and objectives: To study the Prevalence and Molecular Characterization of MRSA isolates from Pus and Blood Samples with Special Reference to MecA and ErmA Gene. Methods: Our study was a retrospective study which was carried out in the Department of Microbiology and Central Research Lab of RMCH &RC for a period of 2 years 4 months i.e, March 2019 to July 2021. The isolates were collected from blood and pus patients of different wards. Phenotypic and Genotypic isolation of MRSA was performed. The bacteria were initially identified by colony morphology, mannitol fermentation, Gram characteristics, catalase test, coagulase test, and DNase activity. In phenotypic methicillin resistance was assessed using the cefoxitin disk diffusion method following the Clinical and Laboratory Standard Institute guidelines (CLSI). The detection of MecA and ErmA genes was done by isolating DNA following DNA amplification. Results: Total 220 isolates were included in our study, out of which 90 were confirmed to be MRSA by CX , OX , E-test and MIC method and remaining 130 were MSSA. From the 90 MRSA isolates, 25 were found to be D test positive, whereas 20 were confirmed cMLSB while the other 25 were noticed to be MS phenotype and 25 were found sensitive phenotypes. All methicillin-resistant staphylococci were tested for their susceptibility against commonly used antibiotics. All MRSA isolates were sensitive to linezolid, Teicoplanin, vancomycin, Gentamycin and Resistance to Cefoxitin and Oxacillin. The presence of MecA gene was detected in all the 90 isolates and the presence of ErmA gene was found in 5 isolates among the MRSA. The presence of MecA and ErmA gene was confirmed by sequencing. The prevalence of MRSA was found to be 40.9% in our study. Conclusions: There is an urgent need to develop better measurements among clinical microbiology laboratories for proper detection, identification, and reporting of MRSA isolates with deep knowledge among physicians toward antibiotic and prescription practices for this multi-drug resistant organism.
