Skip Navigation



JAC Advance Access published online on June 9, 2006
Journal of Antimicrobial Chemotherapy, doi:10.1093/jac/dkl228
This Article
Right arrow FREE Full Text (PDF) Freely available
Right arrow Supplementary Data
Right arrow All Versions of this Article:
58/2/288    most recent
dkl228v1
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 Pan, J.-C.
Right arrow Articles by Liu, K.-Z.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Pan, J.-C.
Right arrow Articles by Liu, K.-Z.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2006. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oxfordjournals.org
Received February 9, 2006
Revised April 29, 2006
Accepted May 5, 2006

Original article

Molecular characteristics of class 1 and class 2 integrons and their relationships to antibiotic resistance in clinical isolates of Shigella sonnei and Shigella flexneri

Jing-Cao Pan 1 *, Rong Ye 2, Dong-Mei Meng 2, Wei Zhang 2, Hao-Qiu Wang 2, and Ke-Zhou Liu 3

1 Microbiology Laboratory, Hangzhou Center for Disease Control and Prevention, Hangzhou 310006, People's Republic of China; Institute for Infectious Disease, Zhejiang University, Hangzhou 310003, People's Republic of China
2 Microbiology Laboratory, Hangzhou Center for Disease Control and Prevention, Hangzhou 310006, People's Republic of China
3 Institute for Infectious Disease, Zhejiang University, Hangzhou 310003, People's Republic of China

* To whom correspondence should be addressed.
Jing-Cao Pan, E-mail: jingcaopan{at}sina.com


  Abstract

Objectives: To analyse the gene cassettes and determine the roles of class 1 and class 2 integrons in antibiotic-resistant strains of Shigella sonnei (n = 31) and Shigella flexneri (n = 33).

Methods: Various molecular techniques, including PCR and Southern-blotting analysis, were used to analyse various markers of class 1 and class 2 integrons in these 64 S. sonnei and S. flexneri isolates collected in Hangzhou, China. The gene cassette arrays in integrons were identified by DNA sequencing and/or restriction fragment length polymorphism. Two genomic DNA fragments, one containing intI1 from a S. flexneri isolate that contains intI1 but lacks 3'-conserved region and another containing intI2 from a S. sonnei isolate, were cloned into pUC19 vectors and sequenced. The links between integron gene cassette arrays and antibiotic resistance were analysed.

Results: Class 2 integrons were present in 80.6% (25/31) of the S. sonnei isolates and 87.9% (29/33) of the S. flexneri isolates. All of these integron 2-positive isolates contained constant gene cassette arrays of dfrA1 + sat1 + aadA1 which confer resistance to trimethoprim and streptomycin. It was demonstrated that the class 2 integron was located in the Tn7 region inside the attTn7 locus downstream of glmS in Shigella. Class 1 integrons were found in 9.4% (6/64) of Shigella spp. isolates. An atypical class 1 integron without a 3'-conserved segment on the Shigella chromosome, termed Shigella atypical class 1 integron (SAI), was present in 84.9% (28/33) of S. flexneri isolates. The SAI contained two gene cassettes, blaOXA30 and aadA1; however, the SAI conferred resistance to ampicillin, but not to streptomycin, in Escherichia coli host. The blaOXA30 and aadA1 cassettes of the SAI seemed to be always coordinately excised or integrated.

Conclusions: Multiple and complex mechanisms involving mobile genetic elements in class 1 and class 2 integrons and antibiotic resistance have been developed in the evolution of Shigella strains.

Keywords: Tn7; blaOXA30; dfrA1; aadA1.
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
 Antimicrob. Agents Chemother.Home page
J.-C. Pan, R. Ye, H.-Q. Wang, H.-Q. Xiang, W. Zhang, X.-F. Yu, D.-M. Meng, and Z.-S. He
Vibrio cholerae O139 Multiple-Drug Resistance Mediated by Yersinia pestis pIP1202-Like Conjugative Plasmids
Antimicrob. Agents Chemother., November 1, 2008; 52(11): 3829 - 3836.
[Abstract] [Full Text] [PDF]

Home page
 J Antimicrob ChemotherHome page
A. Gassama Sow, M. H. Diallo, M. Gatet, F. Denis, A. Aidara-Kane, and M.-C. Ploy
Description of an unusual class 2 integron in Shigella sonnei isolates in Senegal (sub-Saharan Africa)
J. Antimicrob. Chemother., October 1, 2008; 62(4): 843 - 844.
[Full Text] [PDF]

Home page
 J Antimicrob ChemotherHome page
A. Tsakris, A. Ikonomidis, N. Spanakis, A. Poulou, and S. Pournaras
Characterization of In3Mor, a new integron carrying VIM-1 metallo-{beta}-lactamase and sat1 gene, from Morganella morganii
J. Antimicrob. Chemother., April 1, 2007; 59(4): 739 - 741.
[Abstract] [Full Text] [PDF]

Home page
 Antimicrob. Agents Chemother.Home page
V. Dubois, M.-P. Parizano, C. Arpin, L. Coulange, M.-C. Bezian, and C. Quentin
High Genetic Stability of Integrons in Clinical Isolates of Shigella spp. of Worldwide Origin
Antimicrob. Agents Chemother., April 1, 2007; 51(4): 1333 - 1340.
[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.