Characterisation of CTX-M and SHV extended-spectrum beta-lactamases and associated resistance genes in Escherichia coli strains of food samples in Tunisia
Objectives: To assess the occurrence of extended-spectrum β-lactamases (ESBLs) in Escherichia coli isolates of faecal samples of animals (n = 40) and food samples (n = 38) obtained in Tunisia in 2006, and to characterize the type of ESBLs, their genetic environments and the associated resistance gen...
| Autores: | , , , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2007 |
| País: | España |
| Institución: | Universidad de La Rioja (UR) |
| Repositorio: | RIUR. Repositorio Institucional de la Universidad de La Rioja |
| OAI Identifier: | oai:portal.dialnet.es:doc/5bbc689bb750603269e80c02 |
| Acceso en línea: | https://investigacion.unirioja.es/documentos/5bbc689bb750603269e80c02 |
| Access Level: | acceso abierto |
| Palabra clave: | Animals CTX-M-1 CTX-M-14 CTX-M-8 E. coli SHV-5 |
| Sumario: | Objectives: To assess the occurrence of extended-spectrum β-lactamases (ESBLs) in Escherichia coli isolates of faecal samples of animals (n = 40) and food samples (n = 38) obtained in Tunisia in 2006, and to characterize the type of ESBLs, their genetic environments and the associated resistance genes. Methods: Samples were inoculated in supplemented media (2 mg/L cefotaxime) for isolation of broad-spectrum cephalosporin-resistant E. coli isolates (one isolate/sample). ESBLs and their genetic environments as well as integrons and their gene cassette composition were characterized by PCR and sequencing. Results: ESBL-producing E. coli isolates were detected in 10 of the 38 food samples analysed (26%) and in none of the tested animal faecal samples. Genes found were as follows (number of isolates): blaCTX-M-1 (5), blaCTX-M-1 + blaTEM-1b (1), blaCTX-M-14 + blaTEM-1b (2), blaCTX-M-8 (1) and blaSHV-5 (1). All ESBL-positive isolates showed unrelated PFGE patterns. IS Ecp1 and IS 903 were detected surrounding blaCTX-M-14, and IS Ecp1/IS 26 and orf477 surrounding some of the blaCTX-M-1 genes. Four of the ESBL-positive strains harboured class 1 integrons including different gene cassette combinations. Conclusions: ESBLs, mainly of the CTX-M class, are detected in E. coli of food origin in Tunisia, being the first time that this mechanism has been detected in food E. coli strains in Africa. ©The Author 2007. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. |
|---|