Study On The Status Of Toxoplasma Gondii And Neospora Caninum Infections In Chickens And Ducks And The Genotype Distribution Of T.gondii In Hunan Province

Toxoplasma gondii and Neospora caninum are two extremely important opportunistic protozoan parasites.T.gondii can infect almost all warm-blooded animals(including humans)and has a negative impact on human health and social economy.Cats and felines are definitive hosts of T.gondii.N.caninum is an obligate intracellular protozoan parasite that infects many domestic and wild animals.The definitive hosts of N.caninum are dogs and canines,and its intermediate host range is more extensive.Meanwhile,neosporosis is the leading cause of reproductive diseases in cattle worldwide,which has a great economic impact on the development of the farming industry.Although many animals have been shown to act as intermediate hosts for T.gondii and N.caninum,there have been no relevant research on the infection of chickens and ducks in Hunan Province.In this study,650 chicken brain tissues and 588 duck brain tissues were randomly collected from five regions of Hunan Province(eastern,southern,western and northern Hunan)from September 2018 to September 2020,and the extracted brain tissues was used to study the status of T.gondii and N.caninum infection and the distribution of T.gondii genotypes.1.The status of T.gondii infection in chickens and ducks in Hunan ProvinceThe semi-nested PCR was used to detect the B1 gene of T.gondii in the brain tissue DNA of chickens and ducks in this study.The results showed that the molecular prevalence of T.gondii in chickens and ducks were 11.1%(72/650)and 7.7%(45/588),respectively.The data were analyzed using SPSS 22.0(IBM,Chicago,IL,USA),and we found that season and sex may be the two critical factors for T.gondii infection in chickens in Hunan province,the age and sex may be the two critical factors for T.gondii infection in ducks in Hunan province.2.The status of N.caninum infection in chickens and ducks in Hunan ProvinceThe PCR technology was used to detect the N.caninum NC-5 genes of the brain tissue DNA of chickens and ducks in this study.The results showed that three and two positive samples were detected from chickens and ducks,respectively.These sequences were deposited in Gen Bank: MW454870,MW454871,MW454872,MW194292 and MW194293.3.The genotype distribution of T.gondii in chickens and ducks in Hunan ProvinceThe B1 gene-positive samples were typed at 12 genetic markers(SAG1,SAG2(5’+3’SAG2,alter.SAG2),SAG3,BTUB,GRA6,c22-8,c29-2,L358,PK1,and Apico)using the multi-locus PCR-RFLP technology.Only two samples from chickens showed complete genotype at all loci,which were identified as genotype Toxo DB#9 and Toxo DB#52.And only one sample was identified as genotype Toxo DB#9 in chickens.In summary,the molecular investigation of T.gondii and N.caninum in chickens and ducks from Hunan Province showed that infection with aforesaid parasites were detected in chickens and ducks from Hunan Province.By genotyping these T.gondii positive(B1 gene positive)samples,the results indicated that there were two different genotypes in chickens and ducks in Hunan Province.And Toxo DB#52 was reported for the first time in China.This study provides a theoretical basis for the future prevention and control of T.gondii and N.caninum.