Cardiobacterium hominis: review of microbiologic and clinical features.

Cardiobacterium hominis, like other fastidious, opportunistic gram-negative bacilli, including Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, and Eikenella corrodens, is increasingly recognized as a cause of human disease. In this review the microbiologic and clinical features of C. hominis are discussed. The findings are based on observations of two infected patients (the case history of one was reported previously) and on reports in the literature of 32 others. Microbiologically, the chief distinguishing features of C. hominis are its characteristic colonial morphotype and its production of indole. Infection with C. hominis is clinically distinctive because of its chronic course (averaging 169 days among patients with endocarditis), the absence of documented infection outside of the bloodstream, and the high degree of responsiveness to treatment with penicillin.