Affiliation:
1. Assistant Professor, Department of Microbiology, Sant Gadge Baba Amravati University, Amravati, India.
2. Associate Professor, Department of Biotechnology, Sant Gadge Baba Amravati University, Amravati, India
Abstract
Methicillin resistant Staphylococcus aureus (MRSA) is a well recognized problem pathogen all over the world both in the
nosocomial as well as in the community. Accuracy and promptness in the detection of methicillin resistance is of key
importance to ensure correct doses of antibiotic treatment in infected patients as well as control of MRSAisolates in hospital environments. The
present study was aimed to compare the efcacy of the susceptibility testing methods as prescribed by CLSI guidelines. Agar dilution, Disk
diffusion, E test, Ezy- MIC and Hi- comb test were compared for detecting high level methicillin resistance in S aureus. The results for these
phenotypic methods were compared using PCR amplication of the mecAgene as gold standard.
Atotal of 106 strains of S aureus were isolated from clinical samples like blood, surgical specimens, wounds, burns and urine, from a tertiary care
hospital of Central India. Out of 106 S aureus isolates 98 are mecApositive and 8 are mecAnegative. When compared with PCR for mec A, Disk
diffusion- 95.91% sensitivity and 87.5% specicity, Agar dilution method- 96.93% sensitivity and 87.5% specicity, Hi-Comb test- 97.95%
sensitivity and 87.5% specicity and E-test and EZY- MIC shows excellent results with 100% sensitivity, specicity, PPV and NPV. the most
appropriate and accurate test giving 100% concurrence with the Gold standard was E-test and EZYMIC, with EZYMIC being much advanced in
performance and reading results.
Reference19 articles.
1. Chambers H. F, The changing epidemiology of Staphylococcus aureus, Emerg Infect Dis, 7 (2001) 178–182.
2. Milton Jorge de Carvalho, Fabiana Cristina Pimenta, Miyeko Hayashida, Elucir Gir, Adriana Maria da Silva, Caio Parente Barbosa. Silvia Rita Marin da Silva Canini, Silvana Santiago, Prevalence of methicillin-resistant and methicillin-susceptible S. Aureus in the saliva of health professionals, CLINICS, 64(4), (2009), 295-302.
3. Clinical and Laboratory Standards Institute. Performance standards for antimicrobial susceptibility testing 6th informational Supplement, Wayne, PA: CLSI, ( 2006), (document M100-16. 26, Nº. 3).
4. Clinical and Laboratory Standards Institute. Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically, 7th ed, Wayne, PA: CLSI, (2006), (document M7-A7. 26, Nº.2).
5. Baddour M M, AbuElKheir M M, Fatani A J, Comparison of mecA Polymerase Chain Reaction with Phenotypic Methods for the Detection of Methicillin-Resistant Staphylococcus aureus, Curr Microbiol, (2007) 55,473–479.