Skip Navigation



JAC Advance Access published online on March 10, 2004
Journal of Antimicrobial Chemotherapy, doi:10.1093/jac/dkh151
© 2004 by The British Society for Antimicrobial Chemotherapy
This Article
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
53/4/584    most recent
dkh151v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Avison, M. B.
Right arrow Articles by Bennett, P. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Avison, M. B.
Right arrow Articles by Bennett, P. M.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 2004 The British Society for Antimicrobial Chemotherapy

Original article

Analysis of AmpC {beta}-lactamase expression and sequence in biochemically atypical ceftazidime-resistant Enterobacteriaceae from paediatric patients

Matthew B. Avison 1 *, Sarah Underwood 1 , Aki Okazaki 1 , Timothy R. Walsh 1 , and Peter M. Bennett 1

1 Bristol Centre for Antimicrobial Research and Evaluation, Department of Pathology & Microbiology, University of Bristol, School of Medical Sciences, University Walk, Bristol BS8 1TD, UK

* Corresponding author. E-mail: Matthewb.Avison{at}bris.ac.uk.

Received 5 September 2003 ; revised 18 December 2003 ; accepted 23 January 2004

Abstract

Objectives: To analyse the variation of ampC {beta}-lactamase gene sequence and expression in biochemically atypical Enterobacteriaceae isolates, and to identify them definitively.

Methods: {beta}-Lactamase gene-containing recombinant plasmids transformed into Escherichia coli were selected using ampicillin. PCR analysis was used to locate specific ampC and 16S rRNA genes, and the amplicons were sequenced. Random amplified polymorphic DNA PCR was used to group isolates and API 20E biochemical profiling was used to identify them putatively.

Results: Of 50 ceftazidime-resistant clinical Enterobacteriaceae isolates, 36 were identified (>95% confidence)--using API 20E test strips--as being organisms known to express inducible class C {beta}-lactamases (Citrobacter freundii, Enterobacter cloacae, Morganella morganii or Hafnia alvei). The rest were biochemically atypical. Of these, isolate I113, putatively identified as E. coli, possesses a chromosomally encoded ampC which differs by 15% from C. freundii OS60 ampC and by >30% from E. coli ampC. A related ampC gene was found in another seven of the atypical isolates. The use of various identification methods, including ampC sequence analysis, revealed that these I113-like ampC-positive isolates represent Citrobacter murliniae and Citrobacter youngae.

Conclusions: We report sequences for two new Citrobacter spp. ampC genes, and provide evidence that ampC sequencing is a discriminatory method for identifying atypical Citrobacter spp. isolates.

Keywords: Citrobacter, lactamases, overexpression, ceftazidime resistance, phylogeny
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Clin. Microbiol. Rev.Home page
G. A. Jacoby
AmpC {beta}-Lactamases
Clin. Microbiol. Rev., January 1, 2009; 22(1): 161 - 182.
[Abstract] [Full Text] [PDF]

Home page
 Antimicrob. Agents Chemother.Home page
T. Naas, D. Aubert, A. Ozcan, and P. Nordmann
Chromosome-Encoded Narrow-Spectrum Ambler Class A {beta}-Lactamase GIL-1 from Citrobacter gillenii
Antimicrob. Agents Chemother., April 1, 2007; 51(4): 1365 - 1372.
[Abstract] [Full Text] [PDF]

Home page
 Antimicrob. Agents Chemother.Home page
V. I. Enne, A. A. Delsol, J. M. Roe, and P. M. Bennett
Evidence of Antibiotic Resistance Gene Silencing in Escherichia coli.
Antimicrob. Agents Chemother., September 1, 2006; 50(9): 3003 - 3010.
[Abstract] [Full Text] [PDF]

Home page
 J Antimicrob ChemotherHome page
V. C. Gould, A. Okazaki, R. A. Howe, and M. B. Avison
Analysis of sequence variation among smeDEF multi drug efflux pump genes and flanking DNA from defined 16S rRNA subgroups of clinical Stenotrophomonas maltophilia isolates
J. Antimicrob. Chemother., August 1, 2004; 54(2): 348 - 353.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.