Comparison of bison and elk susceptibility to experimental challenge withstrain 2308.

Abstract

INTRODUCTION: Brucellosis is endemic in bison and elk in Yellowstone National Park and surrounding areas. METHODS: A comparative study was conducted using data from naive (&#x202f;=&#x202f;82 and 67, respectively) andstrain RB51 (RB51) vaccinated (n-99 and 29, respectively) bison and elk experimentally challenged with virulentstrain during pregnancy. RESULTS: The incidence of abortion, fetal infection, uterine or mammary infection, or infection in maternal tissues after experimental challenge was greater (&#x202f;<&#x202f;0.05) in na&#xef;ve and vaccinated bison when compared to similar groups in elk. Vaccinated bison had lower (&#x202f;<&#x202f;0.002) abortion rates and recovery offrom fetal or uterine/mammary tissues when compared to na&#xef;ve bison. Vaccinated elk had reduced (&#x202f;<&#x202f;0.01) rates of maternal infection, but rates of abortion and fetal or uterine/mammary infection did not differ (&#x202f;>&#x202f;0.05) from na&#xef;ve elk. Na&#xef;ve and vaccinated bison had greater (&#x202f;<&#x202f;0.05)colonization in placentomes, and parotid and supramammary lymphatic tissues when compared to elk. In elk or bison that aborted, mean colonization in placentome tissues were typically more than 5 logs higher than in animals that did not abort. DISCUSSION: The results of our study suggest differences in disease pathogenesis between these two wildlife reservoirs of.