In vitro study of synergy of ampicillin with ceftriaxone against Listeria monocytogenes

Objectives. To evaluate if the in vitro activity of ampicillin increases when combined with ceftriaxone. Material and methods. The activity of ampicillin and ceftriaxone was evaluated against six Listeria monocytogenes invasive clinical isolates. Ampicillin and ceftriaxone MICs were determined by th...

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Detalles Bibliográficos
Autores: Lepe, José Antonio, Rodríguez-Villodres, Ángel, Martín-Gutiérrez, Guillermo, Luque, Rafael, Aznar, Javier
Tipo de recurso: artículo
Fecha de publicación:2019
País:España
Institución:Universidad Loyola Andalucía
Repositorio:Brújula
OAI Identifier:oai:repositorio.uloyola.es:20.500.12412/4789
Acceso en línea:https://hdl.handle.net/20.500.12412/4789
Access Level:acceso abierto
Palabra clave:Ceftriaxone
Ampicillin
Synergy
Listeria
CNS
Descripción
Sumario:Objectives. To evaluate if the in vitro activity of ampicillin increases when combined with ceftriaxone. Material and methods. The activity of ampicillin and ceftriaxone was evaluated against six Listeria monocytogenes invasive clinical isolates. Ampicillin and ceftriaxone MICs were determined by the broth microdilution method. Synergy was evaluated by checkerboard and time-kill curves methods. Results. All six L. monocytogenes strains were susceptible to ampicillin (MICs 0.25-0.5 mg/L). A bacteriostatic synergy was demonstrated by the FIC index of 0.5 and a 2.5 log10 CFU reduction on the six strains studied for MIC ampicillin plus 16 mg/L ceftriaxone concentrations. Conclusions. The association of ceftriaxone with ampicillin increases the in vitro activity of ampicillin, and therefore could be a valuable option in the treatment of invasive infection by L. monocytogenes.