Objective: To investigate the prevalence and molecular characteristics of Anaplasma infections in sheep and goats in Anhui Province in 2020, so as to provide insights into ovine anaplasmosis prevention and control.
Methods: A total of 355 fresh blood samples were collected from 7 sheep and goat farms in Linquan County of Fuyang City, Lixin County of Bozhou City, Yu'an District of Lu'an City, Wangjiang County of Anqing City, Nanling County of Wuhu City, and Tianchang City and Fengyang County of Chuzhou City in Anhui Province from June to December 2020. A. bovis and A. phagocytophilum 16S ribosomal RNA (16S rRNA) gene, A. ovis major surface protein 4 (MSP4) gene and A. capra citric acid synthase (gltA) gene were amplified using PCR assay in all blood samples, and the prevalence of A. bovis, A. phagocytophilum, A. ovis and A. capra infections was calculated in sheep and goats. In addition, the positive amplification products were sequenced and subjected to genetic evolutionary analysis.
Results: The overall prevalence of Anaplasma infections was 17.5% (62/355) in sheep and goats in Anhui Province, and the prevalence of A. bovis, A. phagocytophilum, A. ovis and A. capra infections was 2.8% (10/355), 2.5% (9/355), 2.5% (9/355), and 7.0% (25/355), while the prevalence of A. bovis and A. phagocytophilum, A. phagocytophilum and A. ovis, A. phagocytophilum and A. capra and A. bovis, A. phagocytophilum and A. ovis co-infections was 0.8% (3/355), 1.1% (4/355), 0.3% (1/355) and 0.3% (1/355), respectively. No Anaplasma was detected in the sheep and goat farms in Fengyang County, while at least three Anaplasma species were detected in other sheep and goat farms, with co-infections of multiple Anaplasma species identified. The prevalence of Anaplasma infections was 14.7% (24/163) in goats and 19.8% (38/192) in sheep, and the prevalence of Anaplasma infections was 31.0% (31/100) in goats and sheep under 6 months of age, and 12.2% (31/255) in goats and sheep at ages of 6 months and older, respectively. A. bovis, A. phagocytophilum, A. ovis and A. capra were identified in sheep and goats of different breeds and ages.
Conclusions: Multiple Anaplasma species infections were commonly prevalent in goats and sheep in Anhui Province in 2020, notably A. phagocytophilum, A. ovis and A. capra, which have zoonotic risks. Improved surveillance and prevention and control of Anaplasma infections are required in sheep and goats in Anhui Province.
［摘要］ 目的 了解2020年安徽省羊群无浆体感染率和分子特征, 为羊群无浆体病防控提供科学依据。方法2020年 6—12月, 从安徽省阜阳市临泉县、亳州市利辛县、六安市裕安区、安庆市望江县、芜湖市南陵县、滁州市天长市和滁州市 凤阳县的7个羊场共采集355份羊新鲜血液样本, 采用基于牛无浆体和嗜吞噬细胞无浆体16S核糖体RNA (16S ribosomal RNA, 16S rRNA) 基因、绵羊无浆体主要表面蛋白4 (major surface protein 4, MSP4) 基因、山羊无浆体柠檬酸合酶 (citric acid synthase, gltA) 基因的PCR技术对所有血液样本进行扩增, 统计羊群中牛无浆体、嗜吞噬细胞无浆体、绵羊无浆体和 山羊无浆体感染率, 并对获得的PCR阳性扩增产物进行测序和遗传进化分析。结果355份羊血液样本中, 无浆体总 感染率为17.5% (62/355), 其中牛无浆体、嗜吞噬细胞无浆体、绵羊无浆体和山羊无浆体感染率分别为2.8% (10/355) 、 2.5% (9/355) 、2.5% (9/355) 和7.0% (25/355), 牛无浆体和嗜吞噬细胞无浆体、嗜吞噬细胞无浆体和绵羊无浆体、嗜吞噬细 胞无浆体和山羊无浆体以及牛无浆体、嗜吞噬细胞无浆体、绵羊无浆体合并感染率分别为0.8% (3/355) 、1.1% (4/355) 、 0.3% (1/355) 和0.3% (1/355) 。除凤阳县羊场未检出无浆体外, 其他羊场均检出至少3种无浆体, 且存在多种无浆体合并 感染。355份羊血液样品中, 山羊羊群和绵羊羊群无浆体感染率分别为14.7% (24/163) 和19.8% (38/192), < 6月龄和≥ 6月 龄羊群无浆体感染率分别为31.0% (31/100) 和12.2% (31/255), 不同品种和年龄羊群中均存在上述4种无浆体感染。结论 2020年安徽省羊群普遍存在多种无浆体感染, 尤其是嗜吞噬细胞无浆体、绵羊无浆体和山羊无浆体, 具有人兽共患风 险; 应加强羊群无浆体感染监测和防控。.
Keywords: