Aerobic, facultatively anaerobic, and obligately anaerobic gram-negative bacteria have been isolated from 10% to 40% of cases of prosthetic valve endocarditis. Such isolates have included Proteus, Escherichia coli, Serratia marcescens, Klebsiella pneumoniae, Enterobacter, Salmonella, Haemophilus, Achromobacter, Acinetobacter calcoaceticus, Alcaligenes faecalis, Actinobacillus actinomycetem-comitans, Eikenella corrodens, Brucella, Cardiobacterium hominis, Neisseria, and Bacteroides fragilis (1, 2). Described herein is the first reported case of prosthetic valve endocarditis caused by Agrobacterium radiobacter, a gram-negative soil bacterium.
A 77-year-old chiropractor was hospitalized in March 1979 for evaluation of fever and weight loss. Blood cultures grew penicillin-sensitive Streptococcus bovis that was treated with 28 days of