Epidemiological Investigation And Characterization Of Toxopasma Gondii Infections In Pigs In Luoyang

Toxoplasmosis was caused by Toxoplasma gondii, which is an obligateintracellular protozoan parasite that infects human and all warm-blooded animals. Theinfection of T. gondii was common and distributed worldwide, with great harmful tohuman heathy.In this study, A total of410sera were collected from pigs in Luoyang, andassayed for T. gondii lgG antibodies by ELISA to investage the prevalence in pigs.And then, hilar lymph nodes and lungs from159pigs were detected by PCR based on200-300copies529bp repetitive sequences of T. gondii. The positive tissues werehomogenized and filtered, and inoculated intraperitoneally into mice for isolation of T.gondii. Then, the isolates were identified by morphology and PCR.The results showed that in the410serum samples of pigs,154samples wereseropositive, with a positive rate of35.4%. The highest positive rate was38.6%inYichuan county, and the lowest positive rate was33.0%in Song county, there was nostatistically significant differences among the four counties (P>0.05). The prevalenceof T. gondii antibodies was higer in free-ranging pigs (43.1%) than that in farmedones (27.4%), with statistically significant differences(P<0.05). The seroprevalence ofT. gondii infection in sows, finishing pigs and nursery pigs were50.4%,34.5%,22.2%, with statistically significant differences among them(P<0.05). Of these159casesof samples, there are17cases detected positivity of T. gondii, the positive ratewas10.7%. the positive rate in sick pigs was18.5%, statistically significant higherthan the rate (6.7%) in slaughter pigs. Three isolates were selected and DNA fragmentof T. gondii were amplificated and sequenced, and these isolates exhibited the highestsequence similarity(97%) to T. gondii RH strain. Seventeen positive tissues (hilarlymph nodes and lungs) were homogenized and filtered, and inoculated intraperitoneally into mice in17groups respectively. Actue toxopasmosis wereobserved in mice of5groups, and numerous of parasites were found in the peritoneallavage. And with97%sequence similarity to RH strain.The results of the present study have shown that a high prevalence of T. gondiiinfection in swine in Luoyang. This stuy will provide important reference value forfurther study on T. gondii genetics, and prevention and control of toxoplasmosis inhuman and animals.