Infection with Dermatophilus congolensis at a contact hypersensitivity site and its relevance to chronic streptothricosis lesions in the cattle of West Africa.

Guinea-pigs were sensitized to CDNB and infected with D. congolensis at the site of a subsequent application of this chemical. The bacterium was recovered from the skin over a longer period of time in sensitized individuals than in nonsensitized controls. Animals rendered tolerant to the chemical gave lower yields of bacteria than sensitized animals. However, the lesions produced at the site of infection did not become chronic. The growth of D. congolensis at a contact hypersensitivity site may possibly simulate infection in skin following an arthropod bite and be relevant to the pathogenesis of chronic streptothricosis lesions in the cattle of West Africa.