Novel extended-spectrum TEM-type beta-lactamase from an Escherichia coli isolate resistant to ceftazidime and susceptible to cephalothin.
A novel extended-spectrum TEM-type beta-lactamase was detected in an Escherichia coli isolate which was resistant to ceftazidime and susceptible to cephalothin. The corresponding bla gene was sequenced. The deduced amino acid sequence showed the following three amino acid replacements with respect to the TEM-2 sequence: Glu-->Lys-104, Arg-->Ser-164, and Glu-->Lys-240. Since it confers a ceftazidimase-type resistance phenotype, we propose for this novel enzyme the designation CAZ-9, corresponding to TEM-46 in the sequential numbering scheme of TEM beta-lactamases.
Chanal-Claris
C
C
Laboratoire de Bactériologie-Virologie, Faculté de Médecine, Clermont-Ferrand, France.
Sirot
D
D
Bret
L
L
Chatron
P
P
Labia
R
R
Sirot
J
J
D002442:Ceftazidime / Q000494:pharmacology*; D018550:Cephalosporin Resistance; D002511:Cephalosporins / Q000494:pharmacology*; D002512:Cephalothin / Q000494:pharmacology*; D015342:DNA Probes; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D007525:Isoelectric Focusing; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D001618:beta-Lactamases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*
D002511:Cephalosporins; D015342:DNA Probes; D002442:Ceftazidime; D001618:beta-Lactamases; D002512:Cephalothin