Mycobacterial Diseases of Animals

<p>NON-TECHNICAL SUMMARY:<br/> JD is a chronic granulomatous inflammatory intestinal disease of ruminants that results from infection with Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis). First identified over a century ago, JD results in more than $200 million in annual losses to the United States (US) dairy industry each year with additional losses incurred by the other species. The growing recognition of M. paratuberculosis infection in wildlife species is also of considerable concern. Similarly, recent evidence of the presence of M. paratuberculosis in retail milk sources is of concern from a milk quality and potential food safety standpoint. JD remains a major concern for producers with very high prevalence rates (68% of all US dairy herds and 95% of those with over 500 cows have at least one JD positive animal. There have been considerable ongoing
efforts made to identify knowledge gaps, define research priorities, and develop recommendations for implementing JD control measures in the field. For instance, a report from the National Research Council of the US National Academies of Sciences on JD concluded that JD is a significant animal-health problem whose study and control deserves high priority from the USDA. It was recognized that the problems associated with JD stem from: (i) difficulties in diagnosis because of an unusually long incubation period and a lack of specific and sensitive diagnostic tests for detecting early infections; (ii) a lack of vaccines or other effective measures for infection control; and, (iii) general lack of awareness of the disease and its true economic and animal-health consequences by producers and veterinarians. The goals of this project are to help address some of these unmet needs.
<p>APPROACH:<br/> Working in collaboration with other investigators who are part of this multi-state initiative, we anticipate participating in investigations that include the development of improved methods for the rapid, specific, sensitive, and cost-efficient diagnosis of JD infected animals. In addition, we envision studies of the basic biology of the causative organisms of JD and TB and their interaction with the host. Specifically, we anticipate studies that will employ state-of-the art microbiological, molecular biology, genomic, proteomic, metabolomic, immunology, and or bioinformatic approaches. Finally, it is well recognized that defining the host genetic, cellular and molecular events associated with susceptibility to JD is essential for the development of candidate vaccines and host genetic selection for resistance. Specifically, our group will participate in
the programs that compare the efficacy of candidate vaccines in animal models of infection. We hypothesize that live attenuated vaccines are likely to elicit a protective response superior to the response elicited by currently available killed vaccines. Pennsylvania Agricultural Experiment Station investigators will take a leadership role in helping coordinate some of these studies, but may not directly participate in all of the bove Taken together, we anticipate that these investigations will reveal important insights into the immune response of animals to mycobacterial infections, as well as lead to the identification and evaluation of candidate vaccines.