Peritonitis due to Neisseria mucosa in an adolescent receiving peritoneal dialysis

Neisseria mucosa is part of the normal nasopharyngeal flora and rarely pathogenic in humans. Reports of serious infections associated with this pathogen are very unusual. A 17-year-old boy with end-stage renal disease due to IgA nephropathy presented with acute, spontaneous, symptomatic peritoneal dialysis-associated peritonitis without reported break in sterility or PD catheter exit site infection. beta-lactamase-negative N. mucosa was isolated from the dialysate effluent. Intraperitoneal antibiotic treatment with cephalothin/gentamicin for 5 days and subsequent ceftriaxone led to complete resolution of the infection. This case demonstrates that "non-pathogenic" Neisseria species can cause clinically severe peritonitis with high intraperitoneal neutrophil counts, elevated C-reactive protein levels in the peritoneal effluent (in the presented case, 27,600/mul and 3.6 mg/l, respectively) and impaired peritoneal membrane transport function. To our knowledge, this is the first case of N. mucosa peritonitis complicating chronic peritoneal dialysis in an adolescent patient.