2024-03-29T11:45:50Zhttp://repisalud.isciii.es/oai/requestoai:repisalud.isciii.es:20.500.12105/85872023-10-10T10:33:59Zcom_20.500.12105_15322com_20.500.12105_2051com_20.500.12105_2060com_20.500.12105_2052col_20.500.12105_16985col_20.500.12105_2061
00925njm 22002777a 4500
dc
Ortega, Adriana
author
Oteo-Iglesias, Jesus
author
Aranzamendi-Zaldumbide, Maitane
author
Bartolomé, Rosa M
author
Bou, Germán
author
Cercenado, Emilia
author
Conejo, M Carmen
author
González-López, Juan José
author
Marín, Mercedes
author
Martínez-Martínez, Luis
author
Merino, María
author
Navarro, Ferran
author
Oliver, Antonio
author
Pascual, Alvaro
author
Rivera, Alba
author
Rodríguez-Baño, Jesús
author
Weber, Irene
author
Aracil, Belen
author
Campos, Jose
author
2012-07
We conducted a prospective multicenter study in Spain to characterize the mechanisms of resistance to amoxicillin-clavulanate (AMC) in Escherichia coli. Up to 44 AMC-resistant E. coli isolates (MIC ≥ 32/16 μg/ml) were collected at each of the seven 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%), hyperproduction 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.
Antimicrob Agents Chemother. 2012 Jul;56(7):3576-81. doi: 10.1128/AAC.06393-11. Epub 2012 Apr 9.
0066-4804
http://hdl.handle.net/20.500.12105/8587
22491692
10.1128/AAC.06393-11
1098-6596
Antimicrobial agents and chemotherapy
Spanish multicenter study of the epidemiology and mechanisms of amoxicillin-clavulanate resistance in Escherichia coli