Prevalence and genetic characterization of Toxoplasma gondii in donkeys in northeastern China.

Toxolasma gondii is one of the most important obligate intracellular protozoan parasites. Recently, toxoplasmosis is of increasing concerns because T. gondii not only has a worldwide distribution but also can infect virtually all warm-blooded hosts including donkeys. However, limited information is available concerning the genetic characterization of T. gondii in donkeys in northeastern China. In this study, a total of 302 brain tissue samples collected from donkeys from Jilin (n=108) and Liaoning (n=194) provinces, northeastern China, were examined for T. gondii infection by semi-nested PCR of B1 gene. The positive samples were genotyped at 11 loci (i.e., SAG1, alternative SAG2, 5'-and 3'-SAG2, SAG3, L358, BTUB, c22-8, GRA6, c29-2, PK1 and Apico) using polymerase chain reaction-restriction fragment length polymorphism technology. Of 302 brain tissue samples, 19 (6.29%) were PCR-positive for T. gondii. The prevalence rates of T. gondii were 6.48% (7/108) and 6.19% (12/194) in Jilin Province and Liaoning Province, respectively. The prevalence of T. gondii in different season groups varied from 5.56% to 7.41%. The prevalence of T. gondii in "Cage-free" donkeys was higher than that in "Captive" donkeys. Of the 19 positive samples, only two isolates were successfully genotyped at all loci, three were genotyped at 9 loci. In total, four samples belong to ToxoDB genotype #9, one belong to ToxoDB genotype #10. This is firstly characterized the T. gondii isolates from donkeys in northeastern China. The results of the present study will improve the information of the distribution of T. gondii genotypes in China.