Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/10/1997
Publication Date: N/A
Technical Abstract: The purpose of this study was to evaluate B. abortus strain RB51 in bison calves under field conditions. Bison calves of approximately 5 months of age were vaccinated with approximately 1.45 x 10(10) CFU of strain RB51. At 4 week intervals beginning at 14 weeks after vaccination, 4 vaccinates were euthanized and samples obtained for bacteriologic, serologic, and histologic evaluation. Standard tube agglutination titers were negative an dot-blot titers were low for the duration of the study. Numbers of calves culture positive for the vaccine strain were 4/4, 4/4, 1/4, 3/4, and 0/4 for 14, 18, 22, 26, and 30 week PI samplings, respectively. The vaccine strain was only recovered from lymphatic tissues. Histological lesions were mild and confined to lymphatic tissues. Our data suggests that strain RB51 in bison does not localize in unusual tissue sites or cause significant histological lesions. Our study indicates that strain RB51 can persist at low levels to 26 weeks after calfhood vaccination of bison. In addition, data from this study suggests that microbiologic evaluation of the superficial cervical lymph node has a strong correlation with the culture status of the calfhood-vaccinated bison.