Genetic Characterization of Toxoplasma gondii Isolates from Pigs in Jilin Province, Northeastern China

Toxoplasma gondii is prevalent in humans and animals worldwide. The present study aimed to determine the genetic diversity of T. gondii isolates from pigs in Jilin province, northeastern China. A total of 100 DNA samples were extracted from the hilar lymph nodes of slaughtered pigs, and 9 (9.0%, 95% confidence interval: 3.4-14.6%) were detected positive for T. gondii B1 gene by a nested polymerase chain reaction (PCR). The positive DNA samples were typed at 11 genetic markers, including 10 nuclear loci (SAG1, 5-SAG2, and 3-SAG2, alternative SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, and PK1) and an apicoplast locus (Apico) using the multilocus PCR-restriction fragment length polymorphism technology. Only three isolates were completely typed at all loci, showing that they all belonged to the clonal type I. One isolate was typed at five loci, including 5 +3-SAG2, SAG2, SAG3, GRA6, and L358, revealing the possible clonal type I. This is the first report of the genetic characterization of T. gondii isolates in pigs in Jilin province, northeastern China, which has implications for better understanding the population structure of T. gondii infection in China.