AAC
Home Help [Feedback] [For Subscribers] [Archive] [Search] --
AAC Accepts, published online ahead of print on 4 June 2007
This Article
Right arrow Full Text (PDF)
Right arrow Other Versions of this Article:
AAC.00026-07v1
51/8/2720    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
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 Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Pallecchi, L.
Right arrow Articles by Rossolini, G. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Pallecchi, L.
Right arrow Articles by Rossolini, G. M.

 Previous Article  |  Next Article 

Antimicrob. Agents Chemother. doi:10.1128/AAC.00026-07
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Rapid Dissemination and Diversity of CTX-M Extended-Spectrum {beta}-Lactamase Genes in Commensal Escherichia coli from Healthy Children from Low-Resource Settings of Latin America

Lucia Pallecchi, Alessandro Bartoloni, Costanza Fiorelli, Antonia Mantella, Tiziana Di Maggio, Herlan Gamboa, Eduardo Gotuzzo, Göran Kronvall, Franco Paradisi, and Gian Maria Rossolini*

Dipartimento di Biologia Molecolare, Sezione di Microbiologia, Università di Siena, Siena, Italy; Dipartimento Area Critica Medico Chirurgica, Clinica Malattie Infettive, Università di Firenze, Florence, Italy; Distrito de Salud Cordillera, Departamento Santa Cruz, Camiri, Bolivia; Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru; Department of Microbiology and Tumor Biology-MTC, Clinical Microbiology, Karolinska Institut, Stockholm, Sweden

* To whom correspondence should be addressed. Email: rossolini{at}unisi.it.


  Abstract

A survey carried out in 2005 among the healthy children population living in Bolivia and Peru revealed that fecal carriage of Escherichia coli resistant to expanded-spectrum cephalosporins was remarkably increased, compared to that observed in the same settings in 2002 (1.7% in 2005 vs. 0.1% in 2002). In this work, we demonstrated that this phenomenon was mainly related to the dissemination of CTX-M-type extended-spectrum {beta}-lactamase (ESBL) determinants among commensal E. coli. Of 50 ESBL-producing isolates collected in the 2005 survey, 44 harboured a CTX-M-type and 6 an SHV-type ESBL (SHV-2 or SHV-12). Compared to 2002, an increased diversity of CTX-M-type ESBLs was also observed: members of the CTX-M-1 group (CTX-M-15) emerged in Bolivia (where only CTX-M-2 was observed in 2002), while members of the CTX-M-9 group (CTX-M-14 and CTX-M-24) emerged in Peru (where only CTX-M-15 and CTX-M-2 were observed in 2002). A new CTX-M-2 variant, named CTX-M-56, was also detected. Molecular characterization of the CTX-M-producing isolates and gene transfer experiments suggested that different mechanisms could be involved in spreading of different CTX-M group determinants, and revealed that additional resistance determinants to non {beta}-lactam antibiotics were preferentially carried by plasmids encoding certain CTX-M variants (CTX-M-15 and variants of the CTX-M-2 group). Three CTX-M-15-encoding conjugative plasmids from Peruvian isolates carried the new fluoroquinolone resistance gene aac(6')-Ib-cr. To our best knowledge, this is the first report of aac(6')-Ib-cr in Latin America.




This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] --
Clin. Vaccine Immunol. Clin. Microbiol. Rev.
J. Clin. Microbiol. ALL ASM JOURNALS

Copyright © 2007 by the American Society for Microbiology. All rights reserved.