title: β-Lactamases in amoxicillin-clavulanate-resistant Escherichia coli strains isolated from a Chinese tertiary hospital.
abstract: A total of 52 strains were resistant to amoxicillin-clavulanate by disk diffusion method in a Chinese tertiary hospital from July 2011 to December 2011. Among these isolates, 2 isolates possessed a phenotype consistent with production of inhibitor-resistant temoniera (TEM) (IRT) β-lactamase, and the TEM-type gene was cloned into strains of Escherichia coli JM109 cells. Both had no blaTEM mutations and were identified as TEM-1 β-lactamase producers. As a result, no IRT β-lactamase was detected. Multiplex PCR detected most of these strains produced TEM-1 enzymes, and plasmid-mediated AmpC β-lactamase and oxacillinase-1 β-lactamases are important mechanisms of resistance as well.
authors.affiliation: Department of Respiratory and Critical Care Medicine, HeNan Provincial People's Hospital, Zhengzhou 450003, China. dingjuanhai@163.com
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Ding
authors.forename: Xitao
authors.initials: X
authors.lastname: Ma
authors.forename: Zhuochang
authors.initials: Z
authors.lastname: Chen
authors.forename: Keqing
authors.initials: K
authors.lastname: Feng
mesh_terms: D019980:Amoxicillin-Potassium Clavulanate Combination / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002681:China; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000188:drug therapy* / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D060885:Multiplex Polymerase Chain Reaction; D010957:Plasmids; D062606:Tertiary Care Centers; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D019980:Amoxicillin-Potassium Clavulanate Combination; C039404:beta-lactamase OXA-2; C048795:AmpC beta-lactamases; D001618:beta-Lactamases; C034413:beta-lactamase TEM-1
keywords: Amoxicillin-clavulanate; Escherichia coli; Inhibitor-resistant TEM; OXA-1; Plasmid-mediated AmpC β-lactamase; Resistance; TEM-1