Short Communication: Association Analysis of Microsatellites and Mycobacterium avium Subspecies paratuberculosis Antibody Response in German Holsteins

Paratuberculosis in ruminants is characterized by chronic granulomatous enteritis, resulting in persistent diarrhea and progressive wasting of cattle infected with Mycobacterium avium ssp. paratuberculosis (MAP). The disease occurs worldwide with high frequency, leading to growing economic losses in beef and dairy industries. The objective of this study was to investigate associations of microsatellites (BMC9006, BB704, BB705, BB717, BB719, BMS1617, BB702, and BOBT24) located near or within candidate genes involved in response mechanisms to paratuberculosis. Pedigree information existed for 4,686 German Holstein cows that had routinely been screened for MAP status using commercially available serum antibody ELISA test. The immunoglobulin G cutoff level was used to classify all animals as positive or negative for paratuberculosis. A total of 594 (12.7%) cows tested positive for paratuberculosis. The control group comprised 585 animals testing negative for MAP. Microsatellite BMC9006 had only 3 alleles (2 of which occurred at very low frequencies in the present data set) and was therefore not informative; the remaining microsatellites showed 3 to 12 alleles. Fisher's exact and chi2 tests revealed no significant differences in microsatellite allele frequencies between the 2 groups of German Holstein cows testing positive or negative for paratuberculosis.