Characterization of the New AmpC beta-Lactamase FOX-8 Reveals a Single Mutation, Phe313Leu, Located in the R2 Loop That Affects Ceftazidime Hydrolysis

A novel class C beta-lactamase (FOX-8) was isolated from a clinical strain of Escherichia coli. The FOX-8 enzyme possessed a unique substitution (Phe313Leu) compared to FOX-3. Isogenic E. coli strains carrying FOX-8 showed an 8-fold reduction in resistance to ceftazidime relative to FOX-3. In a kine...

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Detalles Bibliográficos
Autores: Perez-Llarena, FJ, Kerff, F, Zamorano, L, Fernandez, MC, Nunez, ML, Miro, E, Oliver, A, Navarro, F, Bou, G
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2013
País:España
Institución:Institut d’Investigació Biomèdica Sant Pau (IIB Sant Pau)
Repositorio:r-IIB SANT PAU. Repositorio Institucional de Producción Científica del Instituto de Investigación Biomédica Sant Pau
OAI Identifier:oai:iibsantpau.fundanetsuite.com:p9632
Acceso en línea:https://iibsantpau.fundanetsuite.com/Publicaciones/ProdCientif/PublicacionFrw.aspx?id=9632
https://europepmc.org/article/MED/23877692
Access Level:acceso abierto
Descripción
Sumario:A novel class C beta-lactamase (FOX-8) was isolated from a clinical strain of Escherichia coli. The FOX-8 enzyme possessed a unique substitution (Phe313Leu) compared to FOX-3. Isogenic E. coli strains carrying FOX-8 showed an 8-fold reduction in resistance to ceftazidime relative to FOX-3. In a kinetic analysis, FOX-8 displayed a 33-fold reduction in k(cat)/K-m for ceftazidime compared to FOX-3. In the FOX family of beta-lactamases, the Phe313 residue located in the R2 loop affects ceftazidime hydrolysis and alters the phenotype of E. coli strains carrying this variant.