CMT-type beta-lactamase TEM-125, an emerging problem for extended-spectrum beta-lactamase detection.
Antimicrob Agents Chemother
; 50(7): 2403-8, 2006 Jul.
Article
em En
| MEDLINE
| ID: mdl-16801418
ABSTRACT
The clinical strain Escherichia coli TO799 was resistant to penicillin-clavulanate combinations and ceftazidime and was not reproducibly detected as an extended-spectrum beta-lactamase (ESBL) according to the standards of the Clinical Laboratory Standards Institute (CLSI; formerly NCCLS) and the national guidelines of the French Society for Microbiology (Comité de l'Antibiogramme de la Société Française de Microbiologie). A novel beta-lactamase, designated TEM-125, was responsible for this phenotype. TEM-125 harbors a complex association of mutations previously described in the ESBL TEM-12 and in the inhibitor-resistant beta-lactamase TEM-39. TEM-125 is the first complex mutant TEM to present hydrolytic activity against ceftazidime (kcat, 3.7 s(-1)) together with a high level of resistance to clavulanate (50% inhibitory concentration, 13.6 microM). The discovery of such an ESBL, which is difficult to detect by the usual ESBL detection methods, confirms the emergence of a complex mutant TEM subgroup and highlights the need to evaluate detection methods so as to avoid possible therapeutic failures.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Beta-Lactamases
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Ceftazidima
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Resistência beta-Lactâmica
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Combinação Amoxicilina e Clavulanato de Potássio
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Escherichia coli
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Antibacterianos
Idioma:
En
Ano de publicação:
2006
Tipo de documento:
Article