Inhibitor-resistant TEM (IRT) beta-lactamases with different substitutions at position 244.

AUTOR(ES)

Bret, L

RESUMO

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.

Documentos Relacionados

• First characterization of inhibitor-resistant TEM (IRT) beta-lactamases in Klebsiella pneumoniae strains.
• Characterization of an inhibitor-resistant TEM (IRT) beta-lactamase in a novel strain of Klebsiella pneumoniae.
• Molecular characterization of nine different types of mutants among 107 inhibitor-resistant TEM beta-lactamases from clinical isolates of Escherichia coli.
• Extended-spectrum and inhibitor-resistant TEM-type beta-lactamases: mutations, specificity, and three-dimensional structure.
• Inhibitor-Resistant TEM β-Lactamases: Revision of the TEM-41 Sequence