Indian Journal of Medical Microbiology IAMM  | About us |  Subscription |  e-Alerts  | Feedback |  Login   
  Print this page Email this page   Small font sizeDefault font sizeIncrease font size
 Home | Ahead of Print | Current Issue | Archives | Search | Instructions  
Users Online: 2304 Official Publication of Indian Association of Medical Microbiologists 
 ~   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 Downloaded131    
    Comments [Add]    

Recommend this journal


Year : 2019  |  Volume : 37  |  Issue : 4  |  Page : 488-495

Performance of three commercial assays for colistin susceptibility in clinical isolates and Mcr-1 carrying reference strain

Department of Clinical Microbiology and Immunology, Sir Ganga Ram Hospital, New Delhi, India

Correspondence Address:
Dr. Chand Wattal
Department of Clinical, Microbiology and Immunology, Sir Ganga Ram Hospital, Rajinder Nagar, New Delhi - 110 060
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijmm.IJMM_20_92

Rights and Permissions

Objective: Commercially available antibiotic susceptibility tests (cAST) for colistin are reported to shows variable performance. The current controversy on the colistin susceptibility testing and scarce data from India has left the clinical laboratories in a dilemma on the appropriate and practical approach to tackle the colistin antimicrobial susceptibility testing (AST) issue. This study was aimed to evaluate the performance of commonly used cAST for colistin against broth microdilution (BMD) as the reference method in the clinical isolates. Materials and Methods: Colistin AST was performed on 225 nonduplicate isolates of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii by BMD as the reference method and compared with Vitek-2, Micronaut-S and E-test. The accuracy of the various cASTs was analysed by assessing categorical and essential agreement (EA). Results: We observed an overall categorical agreement of 98.2%, 99.6% and 96.4% and EA of 92%, 92.4% and 72% for Vitek-2, Micronaut-S and E-test, respectively. Unacceptable rates of major error (10.5%) and very major error (21%) were observed for P. aeruginosa with Vitek-2 and E-test, respectively. All the categorical errors (CEs) (7.7%) with Vitek-2 were seen for minimum inhibitory concentrations ranging within two-fold dilution breakpoint of 2 mg/L. Conclusion: Micronaut-S was found to be an acceptable method for colistin AST. In contrast, E-test was unreliable in terms of EA. Vitek-2 was found to be reliable for colistin AST, although it was more prone to CE near the colistin breakpoints.


Print this article     Email this article

2004 - Indian Journal of Medical Microbiology
Published by Wolters Kluwer - Medknow

Online since April 2001, new site since 1st August '04