THE SEAL TUBERCULOSIS AGENT, MYCOBACTERIUM PINNIPEDII, INFECTS DOMESTIC CATTLE IN NEW ZEALAND: EPIDEMIOLOGIC FACTORS AND DNA STRAIN TYPING

Abstract The fur seal (Arctocephalus forsteri), which is abundant in coastal areas of New Zealand, harbors several zoonotic pathogens, including Mycobacterium pinnipedii, a member of the Mycobacterium tuberculosis complex. We describe the microbiology and epidemiology of seven cases of M. pinnipedii infection in beef cattle (Bos primigenius) in coastal areas of New Zealand in 1991–2011. Epidemiologic factors were analyzed on six case farms and a telephone survey of 55 neighboring farms. A DNA-strain typing, using analysis of variable number tandem repeats and the direct repeats (VNTR/DR) of those isolates, was used to compare them to M. bovis isolates commonly found in New Zealand cattle and wildlife. In all cases of M. pinnipedii in cattle, only one animal in the herd was found to be infected. In six of seven cases, the lesions were in the thoracic lymph nodes, indicating a likely aerosol pathway. The lack of multiple cases within a herd suggests that cow-to-cow transmission is uncommon, if it occurs at ...