Meningitis due to Neisseria mucosa: case report and review

Neisseria mucosa is a species of gram-negative cocci that has a characteristic mucoid, adherent colonial morphology and includes pigmented and nonpigmented morphotypes. The ability of N. mucosa to reduce nitrates distinguishes it from other Neisseria species. N. mucosa is part of the normal human nasopharyngeal flora and infrequently causes human infections, including meningitis. We report a unique case of a patient with a cerebrospinal fluid shunt infection due to N. mucosa and review five other reports of cases of meningitis caused by this organism. Seven additional previously reported cases of presumed N. mucosa meningitis have been excluded from this review on the basis of the current criteria for identification of the organism. In the reports of established cases, female infants and children who often had predisposing conditions predominate. Although the outcome for such patients has been favorable, no clinical or laboratory findings are helpful in distinguishing meningitis due to N. mucosa from that due to other bacteria.