Objective: To investigate the prevalence of Echinococcus infections in small rodents around human residential areas in Yushu City, Qinghai Province in 2023, so as to provide insights into precision echinococcosis control.
Methods: One or two quadrats, each measuring 50 m × 50 m, were randomly assigned in Shanglaxiu Township and Longbao Township, Yushu City, Qinghai Province on June 2023, respectively, and 300 plate-type mouse traps, each measuring 12.0 cm × 6.5 cm, were assigned in each quadrat. Small rodents were captured during the period between 10 : 00 and 18 : 00 each day for 4 days. Then, all captured small rodents were identified and dissected, and liver specimens with suspected Echinococcus infections were subjected to pathological examinations. The Echinococcus cytochrome c oxidase 1 (cox1) gene was amplified using PCR assay, and the sequence of the amplified product was aligned to that was recorded in the GenBank to characterize the parasite species. In addition, a phylogenetic tree of Echinococcus was generated based on the cox1 gene sequence using the neighbor-joining method.
Results: A total of 236 small rodents were captured in Shanglaxiu and Longbao townships, Yushu City, including 65 Qinghai voles and 51 plateau pikas in Shanglaxiu Township, and 62 Qinghai voles and 58 plateau pikas in Longbao Township, and there was no significant difference in the constituent ratio of small rodents between the two townships (χ2 = 0.294, P > 0.05). Seven plateau pikas and 12 Qinghai voles were suspected to be infected with Echinococcus by dissection, and pathological examinations showed unclear structure of hepatic lobules and disordered hepatocyte arrangement in livers of small rodents suspected of Echinococcus infections. PCR assay identified E. shiquicus DNA in 7 Qinghai voles, which were all captured from Shanglaxiu Township. Phylogenetic analysis showed that the cox1 gene sequence of Echinococcus in small rodents was highly homologous to the E. shiquicus cox1 gene sequence reported previously.
Conclusions: Plateau pika and Qinghai vole were predominant small rodents around human residential areas in Yushu City, Qinghai Province in 2023, and E. shiquicus infection was detected in Qinghai voles.
［摘要］ 目的 了解青海省玉树市人群聚居区周边小型啮齿类动物棘球属绦虫感染率, 为进一步开展棘球蚴病精准防 控提供参考。方法 2023 年 6 月, 于青海省玉树市上拉秀乡与隆宝镇牧场分别随机设置 1 ~ 2 处 50 m × 50 m 样方, 每个 样方内放置 300 个板式鼠夹 (12.0 cm × 6.5 cm), 每日 10 : 00—18 : 00 捕捉小型啮齿类动物, 持续 4 d。对捕获的啮齿类动 物进行鉴定、剖检, 对疑似棘球蚴感染的肝脏组织进行病理学检查。采用 PCR 法扩增棘球属绦虫细胞色素 c 氧化酶1 (cytochrome c oxidase 1, cox1) 基因, 并与 GenBank 数据库中的序列进行比对以鉴定虫种, 以邻接法构建棘球绦虫系统进 化树。结果 在玉树市上拉秀乡与隆宝镇累计捕获小型啮齿类动物 236 只, 其中上拉秀乡捕获青海田鼠65 只 (占 56.0%)、高原鼠兔 51 只 (占44.0%); 隆宝镇捕获青海田鼠 62 只 (占 51.7%)、高原鼠兔 58 只 (占 48.3%), 两地小型啮齿类动 物构成差异无统计学意义 (χ2 = 0.294, P > 0.05)。剖检共发现7只高原鼠兔和 12 只青海田鼠疑似感染棘球蚴, 病理学检 查可见疑似棘球蚴感染动物肝脏肝小叶结构不清、肝细胞排列紊乱。PCR扩增疑似棘球蚴感染病灶组织DNA, 发现7只 青海田鼠感染石渠棘球蚴, 均捕获自上拉秀乡。系统进化分析发现, 捕获的小型啮齿类动物所感染棘球蚴 cox1 基因序列 与已报道的石渠棘球绦虫 cox1 基因序列高度同源。结论 2023 年青海省玉树市人群聚居区周边小型啮齿类动物以高 原鼠兔和青海田鼠为主, 存在石渠棘球蚴感染。.
Keywords:
Cytochrome c oxidase 1; Echinococcosis;