Department of Veterinary Medicine, Universidade Federal do Paraná, Curitiba, Paraná, Brazil.
Animal Diseases Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Pullman, Washington, United States of America.
PLoS One. 2018 Aug 13;13(8):e0202140. doi: 10.1371/journal.pone.0202140. eCollection 2018.
Anaplasma marginale, the causative agent of bovine anaplasmosis, is a tick-borne bacterium that causes significant economic losses for cattle industries and is increasingly being detected in other animal species. Rhipicephalus microplus is the main vector of this bacterium and may be found parasitizing small ruminants. In northeastern Brazil, multispecies grazing is a common family subsistence practice on smallholder farms possibly facilitating interspecies transmission of pathogens. Considering that A. marginale infection has been previously molecularly described in sheep, this study has aimed to estimate the prevalence of A. marginale and factors associated with the infection in goats from northeastern Brazil. A total of 403 goat blood samples were included in the study. An epidemiological questionnaire was applied to each farm owner addressing age, gender, presence of ticks and multispecies grazing. All samples were screened for A. marginale- and A. ovis-infection using primers targeting the Anaplasma spp. msp4 gene. The identity of A. marginale in the blood was confirmed by PCR amplification of msp5 followed by sequencing. Anaplasma spp. were differentiated by sequencing of the repeat region of the msp1α gene. For the statistical analysis the Chi-square or the Fisher's exact test was used to verify association of the individual factors (age, gender, presence of ticks, and multispecies grazing) with Anaplasma spp. infection. We report the first molecular detection of A. marginale in goats from northeastern Brazil, based on msp1α, msp4 and msp5 gene sequencing analysis. Sequencing of the detected A. marginale msp1α gene revealed the F repeat. Amblyomma parvum and R. microplus were found feeding on animals.
绵羊边缘无浆体感染的分子描述，因此本研究旨在估计巴西东北部山羊的边缘无浆体感染率及其相关因素。共纳入 403 份山羊血样。对每个农场主应用流行病学问卷，内容涉及年龄、性别、蜱虫存在和多种物种放牧情况。使用针对无浆体 spp. msp4 基因的引物对所有样本进行边缘无浆体和无浆体 ovis 感染筛查。使用 msp5 的 PCR 扩增和测序确认血液中边缘无浆体的存在。通过 msp1α 基因重复区的测序来区分无浆体 spp.。为了进行统计分析，使用卡方或 Fisher 确切检验来验证个体因素（年龄、性别、蜱虫存在和多种物种放牧）与无浆体 spp. 感染的关联。我们根据 msp1α、msp4 和 msp5 基因测序分析，首次报告了巴西东北部山羊的边缘无浆体分子检测。检测到的边缘无浆体 msp1α 基因的测序显示 F 重复。发现了阿氏钝缘蜱和微小牛蜱在动物身上吸血。
