Activité de l’amoxicilline in vivo dans l’endocardite expérimentale du lapin à Corynebacterium diphtheriae non toxinogène

Abstract

The mortality of non-toxigenic Corynebacterium diphtheriae endocarditis is high (27%). One explanation could be tolerance to amoxicillin. The aim of this work was to evaluate in vivo the tolerance phenomenon, in a rabbit endocarditis experimental model. Two strains of non-toxigenic Corynebacterium diphtheriae were compared: a tolerant one and a non-tolerant one. Each animal was randomly assigned to one of the following groups: no treatment, continuous infusion of amoxicillin simulating 200 mg/kg/24 h in humans, or fractionated infusion of amoxicillin simulating 66 mg/kg/8 h in humans. Surviving bacteria were counted in vegetations after one or three days of treatment. The 24 h fractionated amoxicillin infusion was more efficacious on the non-tolerant strain than on the tolerant strain. On the tolerant strain, 24 h amoxicillin was more efficacious as a continuous infusion than as a fractionated one.