Isolation and identification of Mycobacterium peregrinum from the Pacific white shrimp Penaeus vannamei

Mycobacterium peregrinum was isolated from multifocal, melanized nodular lesions in the carapace of the cultured marine shrimp Penaeus vannamei. This is the first identification of this species of Mycobacterium in shrimp. The lesions appeared to be the result of opportunistic infections in otherwise healthy animals. The presence of M. peregrinum in cultured shrimp has a direct negative impact on the marketability of shrimp because it causes obvious black lesions. The potential for accidental infections of shrimp farm or packing plant workers from handling infected shrimp is of concern since nodular skin lesions induced by the bacterium are difficult to treat.