Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 
  Users Online: 564 Home Print this page Email this page Small font sizeDefault font sizeIncrease font size  
Year : 2012  |  Volume : 2  |  Issue : 2  |  Page : 84-91

Evaluation of phenotypic with genotypic methods for species identification and detection of methicillin resistant in Staphylococcus aureus

1 Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, 5th Mile, Tadong, East Sikkim, India
2 Molecular Biology Laboratory, Genetix Biotech Asia (P) Ltd, 71/1, First Floor, Shivaji Marg, New Delhi, India

Correspondence Address:
Kunsang O Bhutia
Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, 5th mile, Tadong, East Sikkim
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/2229-516X.106348

Rights and Permissions

Background : Phenotypic methods for the detection of methicillin resistance are inadequate, due to presence of hetero-resistant population and dependence of environmental factors that may affect the phenotypic expression of resistance. Aims: Present study was conducted, to evaluate the efficacy of phenotypic methods for the identification of species and mec-A mediated resistance in S. aureus with polymerase chain reaction (PCR), and to assess the prevalence of the Panton-Valentine leukocidin (pvl) toxin in methicillin resistant S. aureus (MRSA) and overall S.aureus population. Materials and Methods: A total of 200 clinical isolates of Staphylococci were subjected to phenotypic and genotypic methods for the species identification and detection of MRSA. Results : The specificity and sensitivity of conventional methods in the detection of S.aureus, was found to be 100 and 97.59% respectively. However, the performance of phenotypic methods in the detection of MRSA were: Oxacillin disc diffusion (DD)-sensitivity 70.58%, specificity 75.75%; cefoxitin DD-sensitivity 86.27%, specificity 83.33%; and oxacillin agar dilution-sensitivity 92.15%, specificity 90.90%. PVL gene was detected in all mec-A positive isolates irrespective of their types. Conclusion:Phenotypic methods still preferred for the species identification, but for the reliable detection of MRSA an algorithm should include a combination of tests and apply a genotypic method for confirmation of resistance isolates showing discrepant results. Considering the high prevalence of PVL-MRSA, we recommend PCR as assay, as it has an advantage of simultaneous detection of mec-A and pvl genes by multiplex PCR.

Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)

 Article Access Statistics
    PDF Downloaded786    
    Comments [Add]    
    Cited by others 11    

Recommend this journal