title: Evaluation of Genotypic and Phenotypic Methods for Detection of Methicillin Resistant Staphylococcus aureus in a Tertiary Care Hospital of Eastern Odisha.
abstract: BACKGROUND
  Methicillin resistant Staphylococcus aureus has emerged as an important pathogen in nosocomial and community acquired infections. Accurate and rapid identification of MRSA in clinical specimens is essential for timely decision of effective antimicrobial chemotherapy.
  
  
  OBJECTIVE
  The present study was conducted to compare efficacy of four conventional phenotypic methods, with mec- A based polymerase chain reaction (PCR) for MRSA identification.
  
  
  METHODS
  Methicillin resistance was determined in 200 S.aureus isolates by oxacillin disc diffusion, cefoxitin disc diffusion, Oxacillin Resistance Screening Agar and E-test. The results were compared with mec-A based PCR.
  
  
  RESULTS
  Among 200 S.aureus isolates 62 (31%) were positive for mec-A gene by PCR. Cefoxitin disc diffusion, Oxacillin Resistance Screening Agar and E-test showed 100% specificity. Oxacillin disc diffusion had lowest sensitivity (82.5%) and specificity (98.5%) among all. The conventional methods take more time than PCR for diagnosing MRSA. Linezolid, Vancomycin & Dalfopristin were the highly sensitive drugs against MRSA isolates.
  
  
  CONCLUSIONS
  Cefoxitin disc diffusion, is rapid, simple and cheaper, hence can be used routinely as an alternative to PCR for detection of MRSA in resource constraint laboratories.
authors.affiliation: Assistant Professor, Department of Microbiology, S.C.B Medical College , Cuttack, India .
authors.forename: Rakesh Kumar
authors.initials: RK
authors.lastname: Panda
authors.affiliation: Associate Professor, Department of Microbiology, AIIMS , Bhubaneswar, India .
authors.forename: Ashoka
authors.initials: A
authors.lastname: Mahapatra
authors.affiliation: Professor, Department of Microbiology, Kalinga Institute of Medical Sciences , Bhubaneswar, India .
authors.forename: Bandana
authors.initials: B
authors.lastname: Mallick
authors.affiliation: Professor and Head, Department of Microbiology, S.C.B Medical College , Cuttack, India .
authors.forename: Nirupama
authors.initials: N
authors.lastname: Chayani
keywords: Cefoxitin; E-test; MRSA; ORSA; mec A