First study of Brucella ovis antibodies in purebred sheep flocks in the State of Parana, Brazil

ABSTRACT Brucella ovis, a non-zoonotic species, is the etiological agent of ovine brucellosis, an infectious disease of clinical or subclinical occurrence in sheep flocks. Until then, there is no serological study of anti-Brucella ovis antibodies in purebred sheep herds. This study aimed to determine the presence of anti-Brucella ovis antibodies in purebred sheep flocks with breeding purposes from Parana State. Blood samples from 728 animals, of which 563 were females and 165 males, between 8 and 56 months of age from the six major sheep producing mesoregions of Parana, were submitted to detection of anti-Brucella ovis antibodies by the Agar Gel Immunodiffusion technique using an antigen from the bacteria Brucella ovis (Reo 198). The results indicate the presence of this disease in purebred sheep from Parana State in a low occurrence of 0.27% (2/728). The only two positive animals were rams, Santa Inês breed, from the same flock in the East Center region of Parana, without clinical disease. In conclusion, Brucella ovis is present in purebred sheep in Parana State, Brazil, and this low occurrence may have occurred due to rigorous breeding systems that may contribute to reduce the transmission of this disease.

摘要 绵羊布鲁氏菌（Brucella ovis）是一种无人畜共患性的菌种，为绵羊布鲁氏菌病的病原体，该病可在绵羊种群中引发临床或亚临床感染。此前，尚无针对纯种绵羊种群中抗绵羊布鲁氏菌抗体的血清学研究。本研究旨在检测巴西巴拉那州（Parana State）具备育种用途的纯种绵羊种群中抗绵羊布鲁氏菌抗体的存在情况。研究采集了来自巴拉那州六大绵羊主产中观区域的728只绵羊的血液样本，其中雌性563只、雄性165只，年龄介于8至56月龄之间；采用基于绵羊布鲁氏菌（Reo 198菌株）抗原的琼脂凝胶免疫扩散（Agar Gel Immunodiffusion）试验，对样本中的抗绵羊布鲁氏菌抗体进行检测。结果显示，巴拉那州纯种绵羊中存在该疫病，检出率为0.27%（2/728），处于较低水平。仅有的两只阳性动物均为来自巴拉那州东部中心区域同一种群的圣塔伊内斯（Santa Inês）品种公羊，未表现出临床病症。综上，巴西巴拉那州的纯种绵羊种群中存在绵羊布鲁氏菌感染，此次检出率较低的原因可能在于严苛的繁育体系，该体系或有助于降低该病的传播风险。