Serological Survey Of Porcine Contagious Pleuropneumoniain Sichuan Province

Actinobacillus pleuropneumoniae(APP) is the pathogen of Porcine Contagious Pleuropneumonia(PCP).In order to clarifypleuropimirnoniaeinthe prevalence ofSichuanProvince., the study improved and optimized the indirect ELISAmethod for the detection ofantibodiy against APP and had a serological survey of APP in SichuanProvince.1.The improvement of an indirect ELISA for the detection of antibody against APPFirst,we prepared the positive control sera of Actinobacillus pleuropneumoniae 5 derived from pigs.The Actinobacillus pleuropneumoniae 5 is inactivated by formaldehyde and made into a kind of antigen which has 1×1010CFU/ml.It is intramuscular injected into the one-month-old weaned piglets (negative antibody to the Actinobacillus pleuropneumoniae)every two weeks and 2ml each time. The inoculation lasts 6 weeks. A week later, we enhanced the immunization by injecting 2ml(1×1010CFU/ml) of the Actinobacillus pleuropneumoniae 5 into the ear venous. The agar immunodifruse result of the collected serum is 1:8.Second, we improved and optimized the indirect ELISA method for the detection of antibodiy against APP. The best concentration of the coated antigenandthe antiserum were fixed on 1:100 (18.5ug/ml) and 1:160 by the Phalanx Titration. The best concentration of the Rabbit anti-Swine secondary antibody was fixed on 1:5000 by gradient screen.At last, it indicated that the result of this method is consistent with the test result of IHA and even more sensitive than it. The serum test results of the pathogenic E.coli, Streptococcus, Pasteurella multocida, Haemophilus parasuis and Japanese Encephalitis are negative.It shows that the specificity of this method is very well.2.The serological survey in part of SichuanProvinceThe study adopted the improved and optimized indirect ELISA method for the serological survey of the pleuropneumoniae in part of SichuanProvince.580 samples of serum collected during June 2012-December 2013were tested.162 were positive, the rate is 27.93%.The results of different stages of growth:the weaned pigs’positive rate is 25,35%(73/288),the fattening pigs’positive rate is 32.1%(75/234),the adult boar’positive rate is 24.13%(18/58).The detection of different sizes of farms show that the positive rate of large-scale farms is 32.1%(152/474),while the positive rate of small-scale farms is 17.9%(19/106).The study confirmed that the fattening pigs in different farms in Sichuan infect APP seriously,especially in Meishan,Yaan,Leshan,Ziyang,Chengdu and Deyang.Pigs’ infection of APP in the large-scale farms is more terrible than that in the small-scale farms.