Establishment Of Indircet Hemagglutination Assay For Antibodies Detection Of APP And Serological Survey Of APP In Jiangxi Province And Nearby Areas

Actinobacillus Pleuropneumoniae belongs to the genera of Pasteurella actinobacillus,it isthe causative agent of Porcine contagious pleuropneumoniae,and it causes the respiratorydisease of swines. It brought huge economic losses to the swine industry worldwide.Because of the pathogenic bacteria are often hidden state, and it may outbreaks of at anytime. Detection herd serum antibody levels to understand the infection status of the herd,so as control and prevention of the prevalence of the disease, it has very importantsignificance.The test is to rejuvenize the APP strains which has been identified and saved.To extractthe O antigen from culture broth by repeated freezing and thawing and ultrasonic lysis,andthen sensitized the rabbit red blood cells,which has been glutaraldehyde fixed-tannicacid.Established a method of indirect hemagglutination assay （IHA） for antibody detectionof APP.The positive sera of hog cholera virus, porcine reproductive and respiratorysyndrome virus, pseudorabies virus showed negative. By the IHA detection in differentbatches of APP antigen, showed good repeatability. Results proved that establishment ofIndircet Hemagglutination Assay for antibodies detection of APP, showed preferablyspecificity and good repeatability.10170serum samples from January2011to December2012, from Jiangxi and thesurrounding areas were tested by using Indireet Hemagglutination Assay （IHA） for APPantibody,in order to make serological investigation. The results showed that the totalpositive rate were82.0%. The highest positive rate area was Fuzhou City,which was92.8%（620/668）,and the lowest positive rate area was Jingdezhen City,which was60.8%（62/102）.Pingxiang’s average antibody titer was the highest,which was1:2^5.86, andJingdezhen’s average antibody titer was the lowest,which was1:2^4.68. In terms of differentstages of swine, from piglets to finishing pigs and then to the boar or sow, the positive rateand the average number of antibody titers were showed an upward trend. In terms ofdifferent seasons,the positive rate in winter and spring is higher than summer and fall. Onthe contrary,the average number of antibody titers in winter and spring is lower thansummer and fall.Survey found that serum samples by two years, in2012compared with2011, exceptJanuary, month-positive rate has increased in varying degrees. Which means that thedisease and the situation is still worse, should arouse the attention of the majority ofveterinary workers.