| Toxoplasma gondii is an important zoonotic parasite that can infect more than 200 species of animals,including humans.The disease has a serious impact on human safety and health and the development of animal husbandry.With the development of economy,the number of people raising dogs and cats is increasing.Dogs and cats,as important hosts of Toxoplasma gondii,bring lots of risks to humans.Chickens and goats are important food sources for humans.They are also important intermediate hosts for Toxoplasma gondii.Once infected,people’s food health problems will be seriously threatened.Epidemiological reports of toxoplasmosis in Guangxi are rare in dogs,cats,chickens and goats.Therefore,in this study,modified agglutination test(MAT)was conducted to detect Toxoplasma gondii in dogs,cats,free-range chickens,and free-range goats in parts of Guangxi.In order to understand the infection of Toxoplasma gondii in this area and systematically analyze the risk factors affecting Toxoplasma gondii infection,I hope to provide a reference for the prevention of Toxoplasma gondii in local people and animals.Modified agglutination test(MAT)is known as a golden standard for detection of Toxoplasma gondii.The test has the characteristics of high sensitivity and high specificity,and is widely used in Europe and the United States.MAT uses a large number of Toxoplasma gondii tachyzoites as diagnostic antigens.In this experiment,tachyzoites were prepared by two methods:in vivo culture in mice and intracellular culture.According to the test,when the intraperitoneal injection volume of mice is 5×10~5 tachyzoites,1.89×10~7tachyzoites can be propagated,which is the optimal injection volume.VERO and HFF cells were inoculated with 3×10~6 tachyzoites,both of which could produce 3×10~7 tachyzoites,multiplying 10 times.Both methods have their own advantages and disadvantages.Therefore,this study selected two methods for preparation of tachyzoites in mice and cells.Using 6%formaldehyde to fix Toxoplasma gondii antigen,β-mercaptoethanol denatures Ig M in serum and specifically detects Ig G antibodie,0.5%Evans blue staining was used to observe the test results,thus establishing a modified agglutination test for Toxoplasma gondii.Examination of modified agglutination test.The results proved that MAT had high accuracy,with an accuracy rate 100%for detecting negative and positive serum.The positive antibody titer reached 1:3200.No cross-reaction with four positive sera of feline calicivirus,feline coronavirus,neospora canine,and canine pseudorabies,Accurate repeatability,different batches of tachyzoites test the same positive and negative sera,the test results are consistent.Prove that the test can be effectively applied to serological detection of Toxoplasma gondii.It can detect all infected animals,including humans.The operation is simple and the results are easy to read.It is suitable for large-scale toxoplasma epidemiological investigation.The MAT test was used to detect 389 pet dog sera collected in Nanning from 2019 to 2020,106 pet dog sera from Guilin,and 71 serum from domestic dogs in rural areas of Nanning.The positive rates of Toxoplasma gondii were9.77%(38/389),7.55%(8/106),22.54%(16/71).The total positive rate of pet dogs was 9.29%(46/495).The chi-square test was used to analyze the risk factors of Toxoplasma gondii infection,and it was found that the infection rates of Toxoplasma gondii in domestic rural and pet dogs in different surrounding environments in Nanning are very significant(P<0.01).Age and season are risk factors for Toxoplasma gondii infection(P<0.05).Age and pet dog canine Toxoplasma gondii infection rate are extremely significant(P<0.01);there is no significant difference in area and gender from Toxoplasma gondii infection(P>0.05).The MAT test was used to detect 320 serums of pet cats in Nanning from2019 to 2020,89 serums of pet cats in Guilin,and 83 serums of domestic cats in rural areas around Nanning.The positive rates of Toxoplasma gondii were13.44%(43/320),11.24%(10/89),and 28.92%(24/83).The total positive rate of pet cats was 12.96%(43/320).The risk analysis found that the infection rate of Toxoplasma gondii in different feeding environments is very significant(P<0.01);different seasons and ages are the risk factors for cat infection with Toxoplasma gondii(P<0.05);the area,gender and the positive rate of cat infection with Toxoplasma gondii There was no significant difference(P>0.05).The MAT test was used for serological detection of Toxoplasma gondii in768 free-range chickens collected from four counties in Hechi City in 2019.The total positive rate was 14.45%(111/768).Risk factor analysis found that the area,season,and age were all risk factors for free-range chicken infection with Toxoplasma gondii(P<0.05).The MAT test was used to test serum of 339free-range goats older than 6 months in four counties in Hechi City in 2019.The positive rate of Toxoplasma gondii was 12.09%(41/339).A risk analysis of the regions revealed that there were significant differences in the infection of Toxoplasma gondii between different regions(P<0.05).This study established the MAT method which can be applied in the clinic.The results showed that the infection of Toxoplasma gondii in Guangxi is widespread.The infection rates of Toxoplasma gondii in dogs,cats,free-range chickens and free-range goats in Guangxi and the analysis of risk factors provide an important reference for the prevention and treatment of local Toxoplasma gondii. |
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