Leuconostoc species as a cause of bacteremia: two case reports and a literature review.

Two new cases of significant bacteremia caused by Leuconostoc spp. are reported and five others described in the literature are reviewed. Four of the seven patients were under one year old and presented with prolonged diarrhea related to gastrointestinal disorders. The remaining three patients were over 50 years of age and being treated in intensive care units. Six patients had nosocomially acquired catheter-related bacteremia. Leuconostoc spp. are naturally resistant to vancomycin, and five patients had received this antibiotic for prior bacteremia caused by methicillin-resistant staphylococci. The majority of patients presented with fever without severe complications. Penicillin is the treatment of choice and there is no report of any death directly attributable to infection by these microorganisms. Infection with Leuconostoc spp. should be suspected if "vancomycin-resistant streptococci" are isolated from the blood, and recorded as a potential cause of bacteremia in patients with indwelling intravenous catheters.