United States Department of Agriculture, Animal and Plant Health Inspection Service, Center for Epidemiology and Animal Health, National Animal Health Monitoring System, Fort Collins, CO 80523, USA.
United States Department of Agriculture, Agricultural Research Service, Animal Disease Research Unit, Pullman, WA 99164, USA; Washington State University, Department of Veterinary Microbiology and Pathology, Pullman, WA 99164, USA.
Prev Vet Med. 2019 Nov 1;171:104750. doi: 10.1016/j.prevetmed.2019.104750. Epub 2019 Aug 24.
Mycoplasma ovis is a hemotropic bacterium reported to infect sheep, goats, and deer species. Infection in these species can result in anemia, jaundice, and ill-thrift. Although of worldwide distribution, only rare reports of this bacterium in the United States exist. The objectives of this retrospective study were to identify the prevalence and distribution of M. ovis, and identify associated demographic and management risk factors, and reproductive and production outcomes associated with infection on domestic sheep (Ovis aries) operations in the United States. As part of the United States Department of Agriculture (USDA), Animal Plant Health Inspection Service, Veterinary Services' National Animal Health Monitoring System (NAHMS) Sheep 2001 and 2011 studies, blood was collected and sera banked from 21,369 ewes in 2001 and 13,128 ewes in 2011. Participating premises were located in 22 states across the United States for each sample year. In 2015 the USDA, Agricultural Research Service, Animal Disease Research Unit received aliquots of these sera, and DNA was extracted and analyzed by PCR for the presence of M. ovis genomic DNA. Flock presence and mean within-flock prevalence of M. ovis were 73.3% and 23.2%, respectively. Model selection using Mallow's C Criterion was used to determine which variables significantly affected flock presence and within-flock prevalence. The final flock presence model included flock size, year of blood collection, region, and vaccine administration. The final within-flock prevalence model included year of blood collection, interaction between flock size and region, and interaction between reported abortions and grazing with sheep from other operations. Medium and large operations had a higher flock presence and within-flock prevalence. Flock presence was higher in operations that administered any vaccines. Operations that reported any abortions and grazed with sheep from other operations had a higher within-flock prevalence.
绵羊肺炎支原体是一种报道可感染绵羊、山羊和鹿的血源性细菌。在这些物种中感染会导致贫血、黄疸和消瘦。尽管这种细菌在世界范围内分布广泛，但在美国仅有罕见的报道。本回顾性研究的目的是确定绵羊肺炎支原体在美国国内绵羊（Ovis aries）养殖场的流行情况和分布，并确定与感染相关的人口统计学和管理风险因素，以及与感染相关的繁殖和生产结果。作为美国农业部（USDA）动植物卫生检验局兽医服务国家动物健康监测系统（NAHMS）绵羊 2001 年和 2011 年研究的一部分，2001 年采集了 21369 只母羊的血液并储存血清，2011 年采集了 13128 只母羊的血液。在每个样本年份，参与的牧场都位于美国 22 个州。2015 年，美国农业部农业研究局动物疾病研究单位收到了这些血清的样本，提取 DNA 并通过 PCR 分析是否存在绵羊肺炎支原体基因组 DNA。羊群存在率和绵羊肺炎支原体的平均群内流行率分别为 73.3%和 23.2%。使用 Mallow 的 C 准则进行模型选择，以确定哪些变量显著影响羊群存在率和群内流行率。最终的羊群存在模型包括羊群规模、采血年份、地区和疫苗接种。最终的群内流行率模型包括采血年份、羊群规模和地区之间的相互作用以及报告流产和与其他养殖场的绵羊放牧之间的相互作用。中等和大规模的养殖场的羊群存在率和群内流行率较高。接种任何疫苗的养殖场的羊群存在率更高。报告有任何流产且与其他养殖场的绵羊一起放牧的养殖场的群内流行率更高。
