Various spiral-shaped bacteria colonize man and lower mammalian species (1). In humans, infection has been limited to a relatively few genera including Leptospira, Borrelia, and Treponema. We report two cases of bacteremia with a nontreponemal, anaerobic, spiral bacterium. These represent only the second and third reported infections in humans caused by Anaerobiospirillum succiniciproducens (2). This organism may present problems in detection, identification, and susceptibility testing, and may produce important postinfection sequellae.
Case 1: A 52-year-old white man, an alcoholic with cirrhosis, noted the sudden onset of severe abdominal pressure with aching in his back and both legs 8 days before