Ke. Bowenkamp et al., Mycobacterium marinum dermatitis and panniculitis with chronic pleuritis in a captive white whale (Delphinapterus leucas) with aortic rupture, J VET D INV, 13(6), 2001, pp. 524-530
A 16-year-old female white whale, Delphinapterus leucas, died after nearly
18 months of chronic lymphopenia and pyogranulomatous dermatitis. Necropsy
revealed rupture of the aorta with hemorrhage into the cranial mediastinum
and between fascial planes of the ventral neck musculature. Multiple foci o
f ulcerative dermatitis and panniculitis were present across the thorax and
abdomen and surrounded the genital folds. In addition, there was a chronic
proliferative pleuritis with over 20 liters of histiocytic exudate in the
thoracic cavity. Acid-fast bacteria consistent with Mycobacterium sp. were
identified in sections of skin lesions and in cytospins of pleural exudate.
Cultures of pleura and I skin lesion collected at necropsy yielded sparse
growth of an acid-fast bacillus with colony characteristics and morphology
consistent with Mycobacterium marinum. Polymerase chain reaction-restrictio
n fragment length polymorphism (PCR-RFLP) analysis confirmed the presence o
f M. marinum DNA in samples of skin. This is the first documented occurrenc
e of mycobacteriosis in a white whale and is a unique presentation of mycob
acterial dermatitis and panniculitis with chronic pleuritis in a cetacean.
The improved PCR-RFLP protocol utilized in this case unifies techniques fro
m several protocols to differentiate between species of Nocardia and rapidl
y growing mycobacteria clinically relevant to aquatic animals.