Capnocytophaga canimorsus Meningitis – Diagnosis with 16S rDNA PCR when Conventional Methods Failed to Identify the Causative Agent

Abstract

Meningitis whether bacterial or viral, poses many challenges to clinicians as the causative agent is often not found. According to guidelines, it is standard to start empiric treatment before a Cerebrospinal Fluid (CSF) sample is obtained. Meningitis, if not diagnosed and treated early, can lead to high morbidity and mortality rates with serious neurological sequelae. While the most common cases of bacterial meningitis are related to Streptococcus pneumoniae and Neisseria meningitidis, this clinical case report found a rare case of meningitis caused by a zoonotic pathogen, Capnocytophaga canimorsus; a commensal found as part of the normal flora of dogs and cats. This rare organism was identified with the help of broad range 16S ribosomal DNA Polymerase Chain Reaction (rDNA PCR), an emerging technique that is now increasingly useful in rapid diagnosis especially if the offending agent is not timely identified and conventional methods have failed, making diagnosis and management difficult for physicians.