Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/12/2010
Publication Date: 3/12/2010
Citation: Osman, M., Stabel, J.R., Hostetter, J., Nettleton, D., Beitz, D.C. 2010. Prevention of Mycobacterium avium subsp. paratuberculosis Infection in BALB/c Mice by Feeding Lactobacillus acidophilus Strain NP-51. Iowa State University Animal Industry Report. AS Leaflet R2487. Available: http://www.ans.iastate.edu/report/air/2010pdf/R2487.pdf. Interpretive Summary: Johne's disease is a chronic, debilitating intestinal disorder in cattle characterized by diarrhea, reduced feed intake, weight loss and death. Cattle usually become infected as young calves by ingesting feces containing the causative bacteria. However, symptoms of disease do not usually present themselves until the animals reach 3 to 5 years of age or even older. During this time the animal is infected and may be shedding the organism in its feces without showing any clinical signs of disease. In addition to reduced milk production by these animals, they also present a potential infective threat to the rest of the herd. Johne’s disease is difficult to diagnose and therefore to control. Development of therapeutic measures is an important management tool that can be used to reduce the spread of this disease. This study demonstrated that feeding a probiotic (nonpathogenic bacterium) to mice stimulates the immune response and, therefore, may help control Johne’s disease. Further work on the utility of probiotics in dairy calves will determine if it is a useful management tool for dairy producers in allaying the spread of infectious disease to their calves and improving their health.
Technical Abstract: The immune responses of 390 BALB/c mice fed the probiotic Lactobacillus acidophilus strain NP51® and infected with Mycobacterium avium subspecies paratuberculosis (MAP) were evaluated in a 6-month trial. Mice were randomized to nine treatment groups fed either viable- or heat-killed NP51 and inoculated with either viable- or heat-killed MAP or sterile phosphate-buffered saline. Feeding the NP51 resulted in higher numbers of T lymphocytes in the spleen, including the CD8+ cytotoxic T lymphocytes. In addition, feeding NP51lowered the number of immune suppressive T regulatory cells CD4+CD25+ and CD8+CD25+ cells in the spleen. Additionally, feeding the NP51 resulted in higher concentrations of interferon-gamma in the supernatant of splenocytes cultured in vitro. These results suggest that feeding the NP51 to BALB/c mice might prevent the progression of MAP infection in mice.