Spanish Multicenter Study of the Epidemiology and Mechanisms of Amoxicillin-Clavulanate Resistance in Escherichia coli
We conducted a prospective multicenter study in Spain to characterize the mechanisms of resistance to amoxicillin-clavu-lanate (AMC) in Escherichia coli. Up to 44 AMC-resistant E. coli isolates (MIC>32/16 g/ml) were collected at each of theseven participant hospitals. Resistance mechanisms were c...
| Autores: | , , , , , , , , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2012 |
| País: | España |
| Institución: | Universidad de Sevilla (US) |
| Repositorio: | idUS. Depósito de Investigación de la Universidad de Sevilla |
| OAI Identifier: | oai:idus.us.es:11441/40585 |
| Acceso en línea: | http://hdl.handle.net/11441/40585 https://doi.org/10.1128/AAC.06393-11 |
| Access Level: | acceso abierto |
| Palabra clave: | Combinación de amoxicilina clavulanato potásico Farmacorresistencia bacteriana Infecciones por Escherichia coli Epidemiología molecular |
| Sumario: | We conducted a prospective multicenter study in Spain to characterize the mechanisms of resistance to amoxicillin-clavu-lanate (AMC) in Escherichia coli. Up to 44 AMC-resistant E. coli isolates (MIC>32/16 g/ml) were collected at each of theseven participant hospitals. Resistance mechanisms were characterized by PCR and sequencing. Molecular epidemiology was studied by pulsed-field gel electrophoresis (PFGE) and by multilocus sequence typing. Overall AMC resistance was 9.3%. The resistance mechanisms detected in the 257 AMC-resistant isolates were OXA-1 production (26.1%), hyperpro-duction of penicillinase (22.6%), production of plasmidic AmpC (19.5%), hyperproduction of chromosomic AmpC(18.3%), and production of inhibitor-resistant TEM (IRT) (17.5%). The IRTs identified were TEM-40 (33.3%), TEM-30(28.9%), TEM-33 (11.1%), TEM-32 (4.4%), TEM-34 (4.4%), TEM-35 (2.2%), TEM-54 (2.2%), TEM-76 (2.2%), TEM-79(2.2%), and the new TEM-185 (8.8%). By PFGE, a high degree of genetic diversity was observed although two well-defined clusters were detected in the OXA-1-producing isolates: the C1 cluster consisting of 19 phylogroup A/sequence type 88[ST88] isolates and the C2 cluster consisting of 19 phylogroup B2/ST131 isolates (16 of them producing CTX-M-15). Each of the clusters was detected in six different hospitals. In total, 21.8% of the isolates were serotype O25b/phylogroup B2 (O25b/B2). AMC resistance in E. coli is widespread in Spain at the hospital and community levels. A high prevalence of OXA-1 was found. Although resistant isolates were genetically diverse, clonality was linked to OXA-1-producing isolates of the STs 88 and 131. Dissemination of IRTs was frequent, and the epidemic O25b/B2/ST131 clone carried many different mechanisms of AMC resistance. |
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