High-level resistance to ceftazidime conferred by a novel enzyme, CTX-M-32, derived from CTX-M-1 through a single Asp240-Gly substitution.
A clinical strain of Escherichia coli isolated from pleural liquid with high levels of resistance to cefotaxime, ceftazidime, and aztreonam harbors a novel CTX-M gene (bla(CTX-M-32)) whose amino acid sequence differs from that of CTX-M-1 by a single Asp240-Gly substitution. Moreover, by site-directed mutagenesis we demonstrated that this replacement is a key event in ceftazidime hydrolysis
Cartelle
Monica
M
Servicio de Microbiologia, Complejo Hospitalario Universitario Juan Canalejo, C/Xubias de Arriba s/n, 15006 La Coruña, Spain.
del Mar Tomas
Maria
M
Molina
Francisca
F
Moure
Rita
R
Villanueva
Rosa
R
Bou
German
G
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D002442:Ceftazidime / Q000494:pharmacology*; D018550:Cephalosporin Resistance / Q000235:genetics*; D002511:Cephalosporins / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics*; D004927:Escherichia coli Infections / Q000382:microbiology; D007525:Isoelectric Focusing; D007700:Kinetics; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D010994:Pleura / Q000382:microbiology; D001618:beta-Lactamases / Q000235:genetics*
D002511:Cephalosporins; D004269:DNA, Bacterial; D002442:Ceftazidime; C055184:beta-lactamase TEM-3; D001618:beta-Lactamases; C487656:beta-lactamase CTX-M-32, E coli