Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Jiangsu Co-innovation Center for Prevention, Control of Important Animal Infectious Diseases and Zoonosis, Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu Province 225009, PR China; State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China.
Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Jiangsu Co-innovation Center for Prevention, Control of Important Animal Infectious Diseases and Zoonosis, Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu Province 225009, PR China.
Infect Genet Evol. 2019 Nov;75:103984. doi: 10.1016/j.meegid.2019.103984. Epub 2019 Jul 29.
Fasciolosis, a foodborne zoonotic disease, caused by Fasciola species which is considered an important problem for human health and livestock husbandry development. Snails are intermediate hosts of F. hepatica, the epidemiological surveillance of snails can evaluate the transmission risk of this disease in human and livestock. In this study, we developed a nest-polymerase chain reaction (nest-PCR) to detect the DNA of F. hepatica in Radix cucunorica, a prevalent intermediate host of this parasite in northwestern China. The nest-PCR was used to amplify a 208 bp fragment of the second internal transcribed spacer (ITS-2) of F. hepatica with two pairs of primers. The method was able to detect up to 0.16 fg genomic DNA in a 25 μL PCR reaction system even effected with high concentrations of snail DNA, and no cross reaction was observed from the genomic DNA of Paramphistomum cervi, Clonorchis sinensis, Orientobilharzia turkestanicum, Metorchis orientalis, Dicrocoelium chinensis. To evaluate the transmission risk of this disease, 409 snail samples collected from different areas of Gansu province were used to detect and analyze the transmission risk of F. hepatica in this area. Of 409 snail samples, the overall prevalence is 43.76%. The prevalence was 92.75% in Gannan Tibetan Autonomous Prefecture, while no snail was positive for F. hepatica in Linxia Hui Autonomous Prefecture. The nest-PCR was firstly used to detect the infection of F. hepatica in snail. It is a novel, useful and convenient method with high sensitivity and specificity. This study is the first report about the epidemiological surveillance of snail infection by F. hepatica in northwestern China, which will help to evaluate the transmission risk of F. hepatica in northwestern China.
片形吸虫病是一种食源性病原体引起的人畜共患病，由片形科吸虫引起，被认为是人类健康和畜牧业发展的重要问题。蜗牛是肝片形吸虫的中间宿主，对蜗牛进行流行病学监测可以评估这种疾病在人类和家畜中的传播风险。在本研究中，我们开发了巢式聚合酶链反应（nest-PCR）来检测中国西北地区流行的这种寄生虫的中间宿主——黄瓜根中的肝片形吸虫 DNA。巢式 PCR 用两对引物扩增肝片形吸虫的第二内部转录间隔区（ITS-2）的 208bp 片段。该方法在 25µL PCR 反应体系中，即使受到高浓度蜗牛 DNA 的影响，也能检测到低至 0.16fg 基因组 DNA，并且从鹿片形吸虫、华支睾吸虫、阔节裂头绦虫、东方双腔吸虫、中华支睾吸虫的基因组 DNA 中没有观察到交叉反应。为了评估这种疾病的传播风险，我们从甘肃省不同地区采集了 409 个蜗牛样本，用于检测和分析该地区肝片形吸虫的传播风险。在 409 个蜗牛样本中，总体流行率为 43.76%。在甘南藏族自治州，流行率为 92.75%，而在临夏回族自治州，没有蜗牛对肝片形吸虫呈阳性。巢式 PCR 首次用于检测蜗牛感染肝片形吸虫。这是一种新颖、有用和方便的方法，具有高灵敏度和特异性。本研究首次报道了中国西北地区蜗牛感染肝片形吸虫的流行病学监测，有助于评估中国西北地区肝片形吸虫的传播风险。
