Peritonitis due to Leuconostoc species in a child receiving peritoneal dialysis

Leuconostoc species are rarely pathogenic in humans, but may cause infection in patients at risk. A 7-year-old girl with p-ANCA-positive crescentic glomerulonephritis, treated with peritoneal dialysis, developed peritonitis due to Leuconostoc species. She had a history of treatment with vancomycin and a brief course of immunosuppressive therapy. The peritonitis responded well to ampicillin therapy. To date, only 47 cases of Leuconostoc infection, including our patient, have been reported in the medical literature; 25 of the cases occurred in children. Only 1 prior case has been reported in the setting of peritoneal dialysis. The risk factors for Leuconostoc infections are not clear, but commonly associated conditions include immunocompromised status and indwelling medical devices. Leuconostoc species are easily misidentified as streptococci in culture, but they possess inherent resistance to vancomycin despite sensitivity to most other antibiotics. In patients with gram-positive peritonitis, Leuconostoc should be considered as a possible etiological agent, particularly if vancomycin resistance is noted in an organism thought to be a Streptococcus species.