Tuberculosis in seals caused by a novel member of the Mycobacterium tuberculosis complex: Mycobacterium pinnipedii sp. nov

1 Australian Reference Laboratory for Bovine Tuberculosis, Department of Agriculture Western Australia, 3 Baron-Hay Court, South Perth, WA 6151, Australia 2 CONICET and Departamento de Ciencias Marinas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Casilla de Correo 43, (7600) Mar del Plata, Argentina 3 Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, Los Reseros y Las Cabañas, (1712) Castelar, Argentina 4 Fundación Mundo Marino, Avda Décima 157, (7105) San Clemente del Tuyú, Argentina 5 Bristol Zoo Gardens, Bristol BS8 3HA, UK 6 Pathobiology Group, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand 7 Centre for DNA Fingerprinting and Diagnostics (CDFD), Nacharam, Hyderabad 500 076, India 8 AgResearch, Wallaceville Animal Research Centre, Upper Hutt, New Zealand 9 Division of AIDS, STD and TB Laboratory Research, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA 10 Mycobacterium Reference Laboratory, Queensland Health Pathology Services, Prince Charles Hospital, Chermside, Qld 4032, Australia 11 Departamento de Micobacterias, DILACOT, Servicio Nacional de Sanidad y Calidad Agroalimentaria (SENASA), Avda A Fleming 1653, (1640) Martínez, Argentina Correspondence Debby V. Cousins dcousins{at}agric.wa.gov.au A comparison of Mycobacterium tuberculosis complex isolates from seals (pinnipeds) in Australia, Argentina, Uruguay, Great Britain and New Zealand was undertaken to determine their relationships to each other and their taxonomic position within the complex. Isolates from 30 cases of tuberculosis in six species of pinniped and seven related isolates were compared to representative and standard strains of the M. tuberculosis complex. The seal isolates could be distinguished from other members of the M. tuberculosis complex, including the recently defined ‘ Mycobacterium canettii ’ and ‘ Mycobacterium caprae ’, on the basis of host preference and phenotypic and genetic tests. Pinnipeds appear to be the natural host for this ‘seal bacillus’, although the organism is also pathogenic in guinea pigs, rabbits, humans, Brazilian tapir ( Tapirus terrestris ) and, possibly, cattle. Infection caused by the seal bacillus is predominantly associated with granulomatous lesions in the peripheral lymph nodes, lungs, pleura, spleen and peritoneum. Cases of disseminated diseas