PCR Detection of Microbial Pathogens PCR Detection of Microbial ...

PCR for Veterinary Mycobacteria 201
14
Detection of Pathogenic Mycobacteria
of Veterinary Importance
Robin A. Skuce, M. Siobhan Hughes,
Malcolm J. Taylor, and Sydney D. Neill
1. Introduction
1.1. Importance of the Agents
There are a large variety of bacteria that are pathogenic for animals, including
many opportunistic pathogens normally residing in the environment.
Among these diverse veterinary pathogens, mycobacteria are highly significant,
particularly for farmed animal species, as many are zoonotic, and their
impact can have significant economic consequences. The genus Mycobacterium
comprises more than 70 species (1). Many of these are innocuous freeliving
saprophytes, but some are inherently pathogenic for animals (Table 1).
Mycobacterium bovis, the causative agent of bovine tuberculosis, has an
exceptionally broad host range that includes farmed and feral animals, wildlife,
and also humans (2). Bovine tuberculosis can be a serious barrier to the
cattle trade within and between countries with significant agricultural economies.
It is also an occupational zoonosis. Several countries in the developed
world have been unable to eradicate bovine tuberculosis, despite implementing
comprehensive and costly eradication schemes. The disease is epidemiologically
complex, with interbovine transmission and wildlife reservoirs of
infection suggested as the major obstacles to eradication (3).
Johne’s disease or paratuberculosis, a chronic hypertrophic enteritis observed
in cattle and other ruminants, is caused by M. avium subspecies paratuberculosis
and results in significant economic losses to agricultural industries worldwide.
M. avium subspecies paratuberculosis has been implicated in Crohn’s disease in
humans and now is considered a potential zoonotic pathogen (4). Significant
From: Methods in Molecular Biology, vol. 216: PCR Detection of Microbial Pathogens: Methods and Protocols
Edited by: K. Sachse and J. Frey © Humana Press Inc., Totowa, NJ
201