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Horse meat and milk are an important source of nutrition for many Chinese. Previous studies have shown a fairly high prevalence of Toxoplasma gondii infection in horses. However, there is no data concerning the molecular characterization of T. gondii in horses in China. The present study tested 231 cervical lymph node samples of horses from northern China (97 from Jilin, 54 from Liaoning, and 80 from Xinjiang) for the presence of the T. gondii B1 gene by seminested PCR. The B1-positive samples were genotyped at nine nuclear loci, that is, SAG1, alternative SAG2, SAG3, BTUB, c22-8, GRA6, c29-2, PK1, and an apicoplast locus, using PCR-restriction fragment length polymorphism technique. A total of 14 (6.06%) out of 231 samples were T. gondii positive. The overall prevalence of T. gondii in the horses was 5.15% (5/97) for Jilin Province, 5.55% (3/54) for Liaoning Province, and 7.50% (6/80) for Xinjiang Uygur Autonomous Region. Of the 14 positive samples, only 2 were successfully genotyped at all loci, 5 were successfully genotyped at 5-8 loci, and all typed samples belong to ToxoDB genotype no. 9. To our knowledge, this is the first molecular characterization of the T. gondii isolates from horses in China.

Toxoplasma gondii, the causative agent of toxoplasmosis, is carried by a range of intermediate hosts, including pigeons. Eating raw or undercooked pigeon meat, as is common in regions of China, can easily pass on a potentially fatal T. gondii infection. However, there are little data about the seroprevalence and genotypes of T. gondii infection in pigeons. In this study, a total of 963 pigeon blood samples were collected from Jilin Province, Liaoning Province, and Inner Mongolia Autonomous Region in China between August 2015 and December 2016. The overall seroprevalence of T. gondii was 10.80% (104/963), with 8.80% (41/466) in males and 12.68% (63/497) in females. The seroprevalence of T. gondii in different regions varied from 9.04% (17/188) in Jilin City to 13.16% (20/152) in Shenyang City, a relatively high prevalence. The seroprevalence of T. gondii in juvenile pigeons (6.38%, 18/282) was significantly lower than in adults (86/681, p < 0.05). These findings could provide useful data for the execution of effective control measures against T. gondii infection in pigeons and/or other hosts. More importantly, the findings also suggest that pigeons should not be eaten raw.

Chlamydia is considered as one of the most widely prevalent zoonotic pathogens. It can spread from infected birds to human beings through direct or indirect contact with fecal shedding of Chlamydia. However, data concerning prevalence and genotypes of Chlamydia in pigeons are limited. In the present study, a total of 963 serum samples was collected from Jilin Province, Liaoning Province, and Inner Mongolia Autonomous Region (IMAR) in China between August 2015 and December 2016 and the seroprevalence for Chlamydia was analyzed by indirect hemagglutination assay test. The seroprevalence of Chlamydia was 20.4% (215/963) in total, at the cutoff 1:16, with the titers of 1:16 in 109, 1:64 in 49, 1:256 in 38, and 1:1024 in 18. Samples from all six administrative cities were detected Chlamydia-seropositive, ranging from 19.0% to 25.0%. Adult pigeons (23.5%) have a significant higher seroprevalence than juveniles (15.2%). Four PCR-positive samples represented Chlamydia psittaci genotype B. This is the first report of Chlamydia infection in pigeons in Liaoning Province and IMAR. The occurrence of C. psittaci genotype B in the droppings of pigeons suggests potential environmental contamination with C. psittaci and may raise a public health concern.