AmpC β-lactamases in Escherichia coli: emergence of CMY-2–producing virulent phylogroup D isolates belonging mainly to STs 57, 115, 354, 393, and 420, and phylogroup B2 isolates belonging to the international clone O25b–ST131
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- 作者：Jesú ; s Oteo ; Emilia Cercenado ; Ó ; scar Cuevas ; Veró ; nica Bautista ; Alberto Delgado-Iribarren ; Beatriz Orden ; Marí ; a Pé ; rez-Vá ; zquez ; Silvia Garcí ; a-Cobos ; José ; Campos
- 关键词：AmpC ; Escherichia coli ; CMY-2
- 刊名：Diagnostic Microbiology and Infectious Disease
- 出版年：2010
- 出版时间：July 2010
- 年：2010
- 卷：67
- 期：3
- 页码：270-276
- 全文大小：489 K
文摘
Cephalosporins resistance is increasing in Escherichia coli in Spain. We characterize infections by E. coli with reduced susceptibility to third-generation cephalosporins (3GCs) with the AmpC phenotype. Between January 2004 and March 2007, 121 E. coli isolates with the AmpC phenotype were collected (4.8 % of all the 2538 E. coli isolates with reduced susceptibility to 3GCs). These isolates were further characterized by clinical and molecular analysis. Plasmid-encoded ampC genes were detected in 46 (38 % ) isolates (43 CMY-2); 75 isolates (62 % ) had modifications in the chromosomal ampC promoter region (c-AmpC). CMY-2 producers belonged primarily to the more virulent phylogroup D (48.4 % ), whereas most isolates of c-AmpC belonged to phylogroup A (56.4 % ). Bacteremia and infections in children were more frequently produced by CMY-2 producers. CMY-2–producing phylogroup D E. coli belonged to 8 multilocus sequence typing types. Three CMY-2 producers belonged to O25b/ST131/B2 clone. Infections caused by E. coli with the AmpC phenotype may be spreading primarily because of CMY-2–producing phylogroup D isolates, although this enzyme was also detected in the O25b/ST131/B2 clone.