Infected branchial cleft cyst due to Bordetella bronchiseptica in an immunocompetent patient.

A healthy 23-year-old man with fever and a tender mass in his right anterior neck was found to have a branchial cleft cyst infected with Bordetella bronchiseptica. Initial testing suggested a Brucella species, but further laboratory testing identified the organism definitively. B. bronchiseptica infection in healthy adults is an unusual event.