Skip Navigation



JAC Advance Access published online on May 16, 2005
Journal of Antimicrobial Chemotherapy, doi:10.1093/jac/dki150
This Article
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
56/1/87    most recent
dki150v1
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 Sunde, M.
Right arrow Articles by Norström, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sunde, M.
Right arrow Articles by Norström, M.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2005. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oupjournals.org
Received February 15, 2005
Revised March 31, 2005
Accepted April 6, 2005

Original article

The genetic background for streptomycin resistance in Escherichia coli influences the distribution of MICs

Marianne Sunde 1* and Madelaine Norström 2

1 Section of Bacteriology, National Veterinary Institute, 0033 Oslo, Norway
2 Norwegian Zoonosis Centre, National Veterinary Institute, 0033 Oslo, Norway

* To whom correspondence should be addressed.
Marianne Sunde, E-mail: marianne.sunde{at}vetinst.no


  Abstract

Objectives: The aim of this study was to investigate the genetic background for streptomycin resistance in Escherichia coli and perform analysis of the MICs in relation to genetic background.

Methods: The 136 strains investigated, with streptomycin MICs of ≥16 mg/L, originated from meat and meat products and were collected within the frame of the Norwegian monitoring programme for antimicrobial resistance in bacteria from feed, food and animals (NORM-VET). PCR was carried out for detection of the streptomycin resistance genes strA-strB and the integron-associated aadA gene cassettes.

Results: The strA-strB genes and/or an aadA gene cassette were detected in 110 of the 136 (80.9%) strains investigated. The strA-strB genes were the most prevalent, and were detected in 90 strains. The aadA gene cassettes were detected in 29 strains, and nine strains harboured both the strA-strB genes and an aadA gene cassette. The distribution of MICs differed considerably between isolates harbouring the strA-strB genes (solely) (MIC50=128 mg/L) and isolates harbouring an aadA gene cassette (solely) (MIC50=16 mg/L). Strains harbouring both the strA-strB genes and an aadA gene cassette had higher streptomycin MICs than those harbouring either alone.

Conclusions: The distribution of streptomycin MICs in E. coli can be greatly influenced by the genes encoding resistance to streptomycin. The strA-strB genes are probably involved in conferring high-level resistance to streptomycin, whereas the opposite seems to be the case for the aadA gene cassettes. The low-level streptomycin resistance, caused by the presence of aadA gene cassettes in integrons, represents an obstacle in classifying E. coli as susceptible or resistant to streptomycin. Furthermore, the determination of an epidemiological cut-off value for surveillance purposes is also complicated by dissemination of integrons containing the aadA cassettes.

Keywords: epidemiological cut-off values; strA-strB; aadA.
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
 Appl. Environ. Microbiol.Home page
D. Bibbal, V. Dupouy, M. F. Prere, P. L. Toutain, and A. Bousquet-Melou
Relatedness of Escherichia coli Strains with Different Susceptibility Phenotypes Isolated from Swine Feces during Ampicillin Treatment
Appl. Envir. Microbiol., May 15, 2009; 75(10): 2999 - 3006.
[Abstract] [Full Text] [PDF]

Home page
 Appl. Environ. Microbiol.Home page
L. B. Rosengren, C. L. Waldner, and R. J. Reid-Smith
Associations between Antimicrobial Resistance Phenotypes, Antimicrobial Resistance Genes, and Virulence Genes of Fecal Escherichia coli Isolates from Healthy Grow-Finish Pigs
Appl. Envir. Microbiol., March 1, 2009; 75(5): 1373 - 1380.
[Abstract] [Full Text] [PDF]

Home page
 J. Clin. Microbiol.Home page
T.-E. Kim, Y.-W. Jeong, S.-H. Cho, S.-J. Kim, and H.-J. Kwon
Chronological Study of Antibiotic Resistances and Their Relevant Genes in Korean Avian Pathogenic Escherichia coli Isolates
J. Clin. Microbiol., October 1, 2007; 45(10): 3309 - 3315.
[Abstract] [Full Text] [PDF]

Home page
 J Antimicrob ChemotherHome page
D. C. Bean, D. M. Livermore, I. Papa, and L. M. C. Hall
Resistance among Escherichia coli to sulphonamides and other antimicrobials now little used in man
J. Antimicrob. Chemother., November 1, 2005; 56(5): 962 - 964.
[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.