title: CTX-M-14, a plasmid-mediated CTX-M type extended-spectrum beta-lactamase isolated from Escherichia coli.
abstract: Four Escherichia coli isolates harboring CTX-M-14, with a single Ala231-->Val substitution compared to CTX-M-9, had three different ribotypes. Cefotaxime resistance was plasmid encoded and conjugatively transferable. Three isolates had the same plasmid restriction enzyme digestion profile, suggesting clonal spread of a resistant plasmid. A high k(cat)/K(m) value for cefotaxime (20.3 microM(-1) s(-1)) but low values for ceftazidime and aztreonam (< 0.02 microM(-1) s(-1)) were observed in hydrolysis assays, indicating resistance to cefotaxime (MIC > or = 64 microg/ml) but susceptibility to ceftazidime (MIC < or = 2 microg/ml).
authors.affiliation: Division of Clinical Research, National Health Research Institutes, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: L
authors.initials: L
authors.lastname: Ma
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ishii
authors.forename: Feng-Yee
authors.initials: FY
authors.lastname: Chang
authors.forename: Keizo
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Monto
authors.initials: M
authors.lastname: Ho
authors.forename: L K
authors.initials: LK
authors.lastname: Siu
mesh_terms: D019943:Amino Acid Substitution; D001398:Aztreonam / Q000494:pharmacology; D002439:Cefotaxime / Q000494:pharmacology; D002442:Ceftazidime / Q000494:pharmacology; D018550:Cephalosporin Resistance; D002511:Cephalosporins / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D007525:Isoelectric Focusing; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D008997:Monobactams / Q000494:pharmacology; D010957:Plasmids / Q000235:genetics*; D012329:RNA, Bacterial / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013624:Taiwan / Q000453:epidemiology; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism*
chemical_list: D002511:Cephalosporins; D008997:Monobactams; D012329:RNA, Bacterial; D002442:Ceftazidime; C456080:beta-lactamase CTX-M-14; D001618:beta-Lactamases; D001398:Aztreonam; D002439:Cefotaxime