Prevalence and Genetic Characterization of Toxoplasma gondii in Nine Species of Wild Rodents in China

Background: Toxoplasma gondii is a foodborne zoonotic parasite that can infect humans and a variety of warm-blooded animals. Wild rodents play an important role as intermediate hosts of T. gondii, and the survey data of T. gondii in wild rodents in China are limited. Methods: Therefore, from August 2023 to May 2024, a total of 510 brain tissue samples were collected from nine species of wild rodents, and T. gondii was detected using a nested PCR targeting the B1 gene. All positive samples were genotyped at 11 PCR-RFLP markers (i.e., SAG1, 5'-and 3'-SAG2, alternative SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) to determine their genotype. Results: In the present study, out of a total of 510 samples analyzed by nested PCR, three (0.59%) tested positive for T. gondii. It is noteworthy that all three positive samples were derived from female Rattus flavipectus rodents captured in Yunnan Province, where the detection rate was 3.41% (3/88; 95% confidence interval: 0-6.96). Complete genotyping was successfully performed on these three samples, revealing two to be of the ToxoDB #9, which is a common and widely distributed strain in China. The third sample presented a novel genotype. Conclusion: This finding suggests that wild rodents could be harboring a variety of T. gondii genotypes, including new genotypes, which may have significant implications for understanding the epidemiology of the parasite and its potential to cause disease in humans and animals.