title: Inhibitor-resistant TEM (IRT) beta-lactamases with different substitutions at position 244.
abstract: A novel inhibitor-resistant TEM (IRT) beta-lactamase was detected in an Escherichia coli isolate resistant to amoxicillin-clavulanate and susceptible to cephalothin. The substrate and inhibitor profiles of this beta-lactamase were similar to those of IRT-1 and IRT-2. The novel IRT's bla gene was sequenced, and the deduced amino acid sequence showed the amino acid replacement Arg for His-244 of the TEM-1 sequence. Substitutions for Arg-244 have been reported in three TEM-1 mutants: IRT-1 (which corresponds to TEM-31) (Cys), IRT-2/TEM-30 (Ser), and TEM-41 (Thr). We designated this novel beta-lactamase, which corresponds to TEM-51, IRT-15.
authors.affiliation: Laboratoire de Bactériologie, Faculté de Médecine, Clermont-Ferrand, France.
authors.forename: L
authors.initials: L
authors.lastname: Bret
authors.forename: E B
authors.initials: EB
authors.lastname: Chaibi
authors.forename: C
authors.initials: C
authors.lastname: Chanal-Claris
authors.forename: D
authors.initials: D
authors.lastname: Sirot
authors.forename: R
authors.initials: R
authors.lastname: Labia
authors.forename: J
authors.initials: J
authors.lastname: Sirot
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology*; D008826:Microbial Sensitivity Tests; D013329:Structure-Activity Relationship; D001618:beta-Lactamases / Q000737:chemistry* / Q000187:drug effects; D047090:beta-Lactams
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D001618:beta-Lactamases; C034413:beta-lactamase TEM-1