云南边境地区肉牛弓形虫感染情况调查及基因分型研究

Investigation and genotyping of Toxoplasma gondii infection in beef cattle in Yunnan border areas

目的 为了解云南省边境地区肉牛弓形虫感染的流行情况,分别从德宏傣族景颇族自治州、保山市、西双版纳傣族自治州等地区,共采集858头肉牛组织样品2 574份。方法 本研究分别提取其组织DNA,利用巢式PCR方法对弓形虫SAG3基因进行检测,在此基础上针对阳性DNA样本SAG3基因开展了PCR-RFLP分型研究,初步确定了主要流行株的基因型。结果 该批组织样品中有来自89头牛呈弓形虫SAG3基因阳性,弓形虫总感染率为10.37%(89/858)。不同地区、不同品种肉牛之间弓形虫感染率具有显著的差异(P<0.05),其中,德宏地区的样品均显示为阴性,而保山、西双版纳地区的阳性率分别为0.33%(1/300,95%CI=0.00~0.99)、25.14%(88/350,95%CI=20.60~29.69);不同品种中,黄牛感染率最高(23.73%)。基因分型结果显示,云南省边境地区肉牛感染为SAG3表面抗原Ⅰ型。结论 本研究通过对云南部分边境地区的肉牛弓形虫感染情况进行调查,为云南边境地区肉牛弓形虫的流行病学研究提供参考数据。

Objective In order to understand the prevalence of Toxoplasma gondii infection in beef cattle in Yunnan Province,2574 tissue samples were collected from 858 beef cattle in Dehong Dai and Jingpo Autonomous Prefecture,Baoshan City and Xishuangbanna Dai Autonomous Prefecture.Methods DNA was extracted and SAG 3 gene of T.gondii was amplified by nested PCR.PCR-RFLP gene typing was performed using DNA sample which was SAG 3 gene positive.Results Showed that 134 samples were positive from 89 of 858 beef cattle were positive for SAG 3 gene of T.gondii,and the total infection rate of T.gondii was 10.37%(89/858).The infection rate of T.gondii was significantly different among beef cattle from different regions and breeds(P<0.05).No T.gondii positive samples were found in Dehong,while the positive rates in Baoshan and Xishuangbanna were 0.33%(1/300,95%CI=0.00-0.99)and 25.14%(88/350,95%CI=20.60-29.69),respectively.It was found that SAG 3 gene of T.gondii in beef cattle in the border areas of Yunnan Province belong to genotype I.Conclusions The infection of T.gondii in beef cattle in the border areas of Yunnan Province was investigated in this study,this study provided reference data for the epidemiological study of T.gondii in beef cattle in Yunnan border areas.