云南省家禽弓形虫感染的流行病学调查及基因分型研究

Investigation and genotyping of Toxoplasma gondii infection in Yunnan Province

为了解云南省家禽中弓形虫感染的流行情况,于2018年3月至2020年12月,在云南省家禽养殖比较集中的地区,从8个规模化家禽养殖场、10个地方鸡养殖场及部分散养户中采集各种家禽血样及土壤样品2802份,采用间接血凝试验(IHA)和套式PCR方法对弓形虫的抗体和核酸分别进行检测,并对核酸检测为阳性的样品通过PCR-RFLP进行了基因分型研究。结果显示:云南省家禽中弓形虫平均抗体阳性率为4.48%,血样、土壤核酸的平均阳性率分别为1.40%和2.74%;不同饲养模式、不同品种、不同地区之间存在一定差异,但地方品种家禽和散养家禽阳性率明显高于规模化养殖场;云南省家禽感染的弓形虫及环境中弓形虫的基因型主要是Ⅰ型,占表面抗原SAG3基因分型的97.92%(47/48)。提示:应重视地方品种家禽和散养家禽中弓形虫病的流行控制,加强饲养管理并采取综合防控措施。

In order to understand the prevalence of Toxoplasma gondii in poultry in Yunnan Province,2802 blood and soil samples were collected from chickens in 8 large-scale poultry farms,10 local chicken farms and some free range chickens of individual farmers during March 2018 to December 2020.Then,indirect hemagglutination assay(IHA)and nested PCR were used to detect the antibody and nucleic acid of T.gondii,respectively,in the samples.PCR-RFLP was used to analyze the genotypes of the positive samples.The results showed that the average antibody positive rate of T.gondii in the samples was 4.48%,and the average antigen positive rates of the blood and soil samples were 1.40% and 2.74%,respectively.There were differences among the chickens of different feeding patterns,varieties and regions,but the positive rates of local breeds and free range chickens were significantly higher than those in the chickens of large-scale farms.The main genotype of the T.gondii infection in the birds and in the environment in Yunnan Province was type Ⅰ,accounting for 97.92%(47/48)of the SAG3 genotypes.The present investigation suggested that the prevention and control of toxoplasmosis in local poultry and free range poultry should receive more attention;and that the management of feeding,comprehensive prevention and control measures should also be adopted.