Meningitis caused by Porphyromonas endodontalis detected by PCR amplification and sequencing of 16S rRNA genes direct from cerebrospinal fluid and cerebral tissue

Abstract

Introduction: Porphyromonas endodontalis (formerly Bacteroides endontalis) is a black-pigmented, non-motile, obligate anaerobe. It has an established role in endodontal infections and has rarely been isolated from other sites. To the best of our knowledge, this is the first time that this organism has been detected as the sole cause of meningitis. This was made possible by the use of direct-on-sample 16S rRNA gene amplification and sequencing. Case presentation: We present a case of meningitis that progressed to a cerebral abscess in an elderly but otherwise immunocompetent male. Despite broad-spectrum antibiotic therapy, the patient died. Conclusion: Although anaerobic meningitis is rarely described, it should be considered if there are clinical and biochemical features of meningitis but no organism isolated on standard aerobic culture.