Meningitis due to Fusobacterium necrophorum

Introduction: Fusobacterium necrophorum is an anaerobic Gram negative bacillus highly virulent, responsible, usually in children or adolescents, of localized abscesses and pharynx, as well as severe systemic infections, called Lemierre syndrome. Methods: A 15 year old child came to the emergency department (ED) of Bambino Gesù Children Hospital. Physicians prescribed chemicalphysical examination on blood and liquor, blood cultures for aerobic and anaerobic bacteria and for fungi (BD Ped Plus, lytic Ana, Micosis), microbiological culture on liquor (CSF) and on the swab from the right outer ear. Results: On chemical examination, liquor appears cloudy, with 309 mg/dl of total proteins, glucose undetectable,WBC 11,160 mmc, 92% of neutrophils. Hyperleukocytosis was detected also on the emocrome (WBC 21x103/μl, 92% neutrophils). No bacterial antigens were detected. CSF culture resulted negative for aerobic bacteria, even after 48 hours of incubation. After 24 hours of inoculation, the blood culture for anaerobic bacteria resulted positive and, Fusobacterium necrophorum was isolated and identified, by genomic sequencing, after 24 hours growth on Schaedler medium. Microbiological culture of the right outer ear swab, highlighted only Corynebacterium spp. After 6 days from admission, the patient died for meningitis. Conclusion:This event has shown the severity of infection by F. necrophorum and, at the same time, the underestimation of this germ in the spectrum of etiologic agents responsible for meningitis.The only microbiological indication was obtained from the anaerobes bacteria blood culture. Following this episode our working procedures for what concerns liquor samples management was modified, including routinely the investigation for anaerobic bacteria. Presumably this episode of meningitis has originated from a F. necrophorum otitis of the right ear, unfortunately not microbiologically confirmed.The anaerobic bacteria should always be considered as potentially responsible of meningitis, especially when ear infections or pharyngeal abscesses precede or accompany the onset of symptoms.