Objectives: To characterize the β-lactamase genes of the expanded-spectrum cephalosporin-resistant Escherichia coli isolates recovered in a Spanish hospital during the March 2002-March 2003 period. Methods: Thirty-four of the 1700 E. coli isolates recovered from unrela ted patients in a Spanish hospital showed expanded-spectrum cephalosporin resistance. The presence of genes encoding TEM, SHV, CTX-M, CMY-2-type or FOX β-lactamases as well as the existence of mutations in the regulatory region of the chromosomal ampC gene were studied by PCR and sequencing in these 34 E. coli isolates. Results: The following extended-spectrum β-lactamases (ESBLs) or plasmidic class C β-lactamase genes were detected (number of isolates): blaCTX-M-14 (14), blaCTX-M-9 (4), blaCTX-M-32 (1), blaTEM-52 (2), blaSHV-12 (3) and blaCMY-2 (2). The remaining eight isolates showed a mutation in the promoter/attenuator region of the ampC chromosomal gene at position -42, in combination with mutations at positions -18, -1 and +58. The blaTEM-1 gene was also detected in 12 of the ESBL-producing isolates, in both CMY-2-producing isolates and in four of the eight isolates that showed a mutation at position -42 of the ampC promoter. Other mutations in the promoter/attenuator region were detected in association with ESBL or CMY-2 genes, such as the combination -18, -1 and +58, -28 and +58, or +22, +26, +27 and +32. No clonal relationship was found among the CTX-M-producing E. coli isolates by PFGE with Xba I enzyme. Conclusions: Approximately 1.5 % of the E. coli isolates of our hospital harboured ESBL genes, those of the CTX-M-9 group being the most common ones. © The Author 2005. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.
CITATION STYLE
Briñas, L., Lantero, M., de Diego, I., Alvarez, M., Zarazaga, M., & Torres, C. (2005). Mechanisms of resistance to expanded-spectrum cephalosporins in Escherichia coli isolates recovered in a Spanish hospital. Journal of Antimicrobial Chemotherapy, 56(6), 1107–1110. https://doi.org/10.1093/jac/dki370
Mendeley helps you to discover research relevant for your work.