Infections Caused by Microorganisms of the Genus Erwinia

Isolates belonging to the genus Erwinia were recovered from 17 outpatients and 14 hospitalized patients during a 15-month period. Only three of the isolates from the outpatients were in pure culture. All isolates from the hospitalized patients were in pure culture, and seven were derived from blood cultures. Two isolates were derived from urine cultures; one each from bone marrow, wound, and pleural fluid culture; and one from the venous site of a Scribner shunt. One patient had a brain abscess caused by Erwinia organisms. Five of the bacteremias seemed to be secondary to contaminated intravenous infusion sets; erwinias were isolated from one of the sets. Erwinia strains were uniformly inhibited by neomycin and gentamicin. Erwinia species were identified by their yellow-pigmented colonies, characteristic symplasmatic formation, anaerogenic fermentation of standard test carbohydrates, and absence of decarboxylase and dihydrolase activities. The epidemiology of recent outbreaks of septicemia caused by this organism is discussed.