[Capnocytophaga canimorsus: atypical septicemic meningitis, approach to microbiological diagnosis and therapeutic impact]

Abstract

Meningitis and septicaemia due to Capnocytophaga canimorsus are extremely rare and described as emerging zoonoses because of their low incidence and prevalence, but also because of the challenges in bacterial identification, thus, the real number of cases is probably underestimated. We report the case of a 61-year-old man, with a history a chronic alcoholism, who developed, following a recent dog bite, meningitis with normoglycorachia and concomitant sepsis, and had a favorable outcome after intravenous probabilistic antibiotherapy combining ceftazidime and metronidazole. This association aimed to cover the risks represented by Pseudomonas spp and anaerobic bacteria, once the microorganisms commonly associated with meningitis were excluded using molecular biology tools. In addition to the unusual biological results (normoglycorachia and bacterial morphology after Gram staining), we present the biological diagnostic approach (molecular, biochemical and physical tools successively used to lead, by exclusion and confirmation, to this diagnosis), closely linked to the clinical expertise. This is, to our knowledge, the first described case of meningitis with normoglycorachia and septicaemia due to Capnocytophaga canimorsus successfully treated with ceftazidime and confirmed by identification by MALDI-TOF mass spectrometry.

Keywords: Capnocytophaga canimorsus; ceftazidime; mass spectrometry; meningitis; septicaemia.