ISSN: 0973-7510

E-ISSN: 2581-690X

Nargis Alom Choudhury1, Debadatta Dhar (Chanda)2, Nivedita Das Gupta1, Anand Prakash Maurya1, Atanu Chakravarty2 and Amitabha Bhattacharjee1
1Department of Microbiology, Assam University, Silchar, India.
2Department of Microbiology, Silchar Medical College and Hospital, Silchar, India.
J. Pure Appl. Microbiol., 2016, 10 (2): 1135-1139
© The Author(s). 2016
Received: 30/12/2015 | Accepted: 01/02/2016 | Published: 30/06/2016

The plasmid-mediated quinolone resistance gene (qnr) encodes a pentapeptide repeat protein that protects type II topoisomerase (DNA gyrase and topoisomerase IV) from quinolone antibiotics, resulting in resistance which is readily transmissible. Plasmid-mediated quinolone resistance (qnr) genes confer low-level resistance but provide background for selection of highly-resistant strains. We investigated quinolone resistance within clinical isolates of enterobacteriaceae and plasmids responsible for their transfer. A prospective, hospital-based study was conducted (September 2013 to march 2014). A total of 245 Consecutive, non-duplicate members of enterobacteriaceae were collected and subjected to screening of qnr resistant determinants, qnr genes detection using multiplex PCR, incompatibility typing and transferability assay was performed. Among 245 clinical isolates, 167 were screened to be resistant towards quinolone group of antibiotics. The quinolone resistance determinant was found to be transferable when transformants were selected in ciprofloxacin (.25µg/ml) screen agar. F inc type (n= 58) was more predominant, followed by K/B (n=40), Y (n=13), I (n=17) and P (n=7) in E.coli and I (n=6), K/B (n=7) in Klebsiella isolates, and K/B (n=6) in case of Proteus isolates when plasmids were typed by PCR based replicon typing. Ciprofloxacin resistance was lost after 48th consecutive serial passage. . The study calls for urgent steps to prevent over the counts availability of quinolone drugs, self medication and routine epidemiological investigation so as to minimize treatment failure due to quinolone therapy.


qnr, Ciprofloxacin, DNA gyrase, PMQR (plasmid mediated quinolone resistance).

Article Metrics

Article View: 679

Share This Article

Journal Tools

© The Author(s) 2016. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License which permits unrestricted use, sharing, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.