| Toxoplasma gondii is a world-wide distribution protozoan parasite,which could infect almost all the worm-blood animals like humans and sheep and avian,causing toxoplasmosis would cause that making abortion,stillbirth,teras and weak fetus of pregnancy animals.The clinical symptoms of intraocular inflammation,lymphadenopathy,non-suppurative encephalitis and death of immunosuppression patients are huge harmful to human.The dates were deficiency and unorganized about toxoplasmosis of sheep and chicken in China.In this study,the seroprevalence and risk factors,isolation,genotyping and pathogenicity were surveyed and researched of Henan,Jiangsu,Zhejiang and Xinjiang of Toxoplasma gondii from sheep and chicken of Henan in China,which could lay a systematic research foundation of toxoplasmosis in livestock and avian.The prevalence and risk factors of toxoplasmosis in sheep and chicken.From October 2014 to November 2016,in total of 913 blood samples of household sheep were collected from Henan(356),Jiangsu(247),Zhejiang(208)and Xinjiang(102).Total of 700 blood samples of free-ranged chicken were collected.All the blood samples were detected by modified agglutination test for the antibody of Toxoplasma gondii.The risk factors of region,gender,abortion history and age were analyzed both sheep and chicken.To the result,the positive percentage of all the sheep was 19.06%(174/913),and the different regions were 23.31% in Henan(83/356),18.22%(45/247)in Jiangsu,21.15%(44/208)in Zhejiang and 1.96%(2/102)in Xinjiang.The positive percentage of all the chicken was 18.86%(132/700).Abortion history and region of sheep were the infection risk factors of toxoplasmosis(P<0.05).However,gender and age had no significant correlation of infection in sheep for this protozoon(P>0.05).The infection risk factors of toxoplasmosis of free ranged chicken was gender(P<0.05)and had no significant correlation of age(P>0.05).The isolations and genotyping of Toxoplasma gondii from sheep and chicken.36(36/377)sheep hearts and 25(25/308)free ranged chicken hearts were selected that all the Toxoplasma gondii antibody titer were ≥100 by MAT,and then the isolates of Toxoplasma gondii in sheep and chicken were achieved which were injected subcutaneously with digestive juice of the selected myocardium.The DNA of Toxoplasma gondii isolation strain were extracted from the tachyzoites cultured by CV-1 cell that inoculated the grinding fluid of brain from the positive mice.The 10 loci(SAG1,SAG2,SAG3,BTUB,GRA6,c22-8,c29-2,L358,PK1 and Apico)PCR-RFLP was used to distinguish the genotyping of the isolates separately.For the result,two positive groups of mice were achieved which named Tg Sheep Hn1 and Tg Sheep Hn2,and their genotypes were all the Chinese1(Toxo DB#9).To our best knowledge,these two viable strains of Chinese1(Toxo DB#9)from sheep were the first report.There was no isolation strains of Toxoplasma gondii achieved from the free-ranged chicken.The pathogenicity of the isolates from sheep isolations.The Toxoplasma gondii tachyzoites were cultured by CV-1 cell and then counted by disposable hemocytometer and diluted in different densities by saline.< 1,100,101,102,103,104 of T.gondii tachyzoites were inoculated by intraperitoneal injection of mice and clinical symptoms and mortality were recorded daily during 60 days.To the dead mice,gross anatomy,observation and fixed all the tissues and organs,and routine paraffin section and H&E staining and immunohistochemical staining were taken to analyze the pathogenicity.The virulence of two isolates were evaluated by the brain cyst load of positive mice,growth time of cell cultured by CV-1,infection rate after tachyzoites inoculation,mortality,and survival time.The pathological lesion and Toxoplasma gondii antibody distribution of dead mice in acute infection were evaluated by H&E and IHC.To the results,the virulence of Tg Sheep Hn1 tachyzoites was stronger than Tg Sheep Hn2,which one tachyzoite could infective mouse and the lowest 100% ethal concentration was 100 and 1000 of tachyzoites.The survival time of acute infection was 10.5d and 22 d,while some mice could tolerate the acute stage and turn to the chronic stage to live.8 day post inoculation(DPI),the main lesions of mice dead in acute toxoplasmosis were observed in small intestine and lung,and other organs were light lesions and had no significant lesions,which accompanied with hyperaemia and inflammation.A focal necrosis of lymphocyte and hyperplasia of reticular cells of parenchyma immune organs.Broadening mesenchyme of pulmonary alveoli,and inflammation and edema around vascular of lung.The numbers of intestinal crypts were reduced,and edema of submucosa,and necrosis and looselyarranged of muscular layer of small intestine.In the acute death of mice in toxoplasmosis(8DPI),the antigens of T.gondii distributed in many organs,which the high distribution density were found in edge of spleen,adrenal gland,mesenteric lymph nodes,small intestine and parts of reproductive organs.These forecast that the main gate of inbreak of two isolates was small intestine.These two isolates of sheep had a powerful ability to infect adrenal gland and reproductive organs.Meanwhile,the antigens of T.gondii were also observed in lung,liver,kidney,myocardium,and brain. |
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