Cutaneous and pulmonary infections caused by Mycobacterium vaccae.

Mycobacterium vaccae is a rapidly growing mycobacterial species that was previously not considered a human pathogen. We report four cases of M. vaccae infection that occurred in the southern United States; one patient had cutaneous disease, and three patients had cavitary lung disease. Two of the three patients with pulmonary disease had a history of exposure to cattle. The conditions of all patients improved with therapy: the cutaneous infection responded to therapy with minocycline and trimethoprim-sulfamethoxazole, and the pulmonary infections responded to therapy with ciprofloxacin.