Systemic Bacillus species infection mimicking listeriosis of pregnancy.

Bacillus species are increasingly recognized as agents of infection in humans. These organisms are ubiquitous in nature and can cause clinical illness ranging from transient bacteremia to serious systemic infection. We describe a pregnant intravenous drug abuser with fever, constitutional symptoms, and premature labor. Her blood cultures yielded gram-positive bacilli, and her clinical course was consistent with systemic listeriosis of pregnancy. Pathological examination of the placenta revealed acute villitis, and Bacillus species grew from cultures of both placenta and blood. Through biochemical testing the isolate was identified as Bacillus pumilis. To our knowledge, this is the first reported case of premature labor induced by Bacillus species infection.