Overproduction of Chromosomal ampC β-Lactamase Gene Maintains Resistance to Cefazolin in Escherichia coli Isolates.

ABSTRACT: Cefazolin, an active in vitro agent against Escherichia coli, is used to treat urinary and biliary tract infections. Cefazolin is used widely as an antibiotic, and the increase in the emergence of cefazolin-resistant E. coli in many countries is a major concern. We investigated the changes in the susceptibility of E. coli clinical isolates to cefazolin following exposure. A total of 88.9% (16/18 strains) of the strains acquired resistance to cefazolin. All strains with an MIC to cefazolin of 2 μg/mL became resistant. The expression of chromosomal ampC (c-ampC) increased up to 209.1-fold in the resistant strains. Moreover, 11 of the 16 E. coli strains (68.8%) that acquired cefazolin resistance maintained the resistant phenotype after subculture in cefazolin-free medium.

SUBMITTER: Kawamura M 

PROVIDER: S-EPMC9241650 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature