Isolation And Identification Of Salmonella Pullorum And Preparation Of Micro Plate Agglutination Antigen

There were many chicken died in a farm of Shaanxi province on December 28,2009. And with symptoms the sticky white loose stool at chicken's cloaca, apparent breathing difficulties, high incidence rate, laying rate and egg quality declined of laying hens, as well as hatching rate decreased and high mortality rate of embryo, it was suspected that those chicken infected by Salmonella pullorum. In order to understand the infectious situation of this farm, pullorum serum plate agglutination test (PAT) was tested. The results showed that there were 88 pullorum positive serums from 93 samples and positive rate was 94.62%. Liver, spleen, lung, hear were collected sterilely from those dead chicken to isolate and identify bacteria. According to the characteristics of bacterial colonies on MacConkey Agar plate, staining and morphological characteristics, biochemical reactions as well as pathogenicity tests, isolated bacteria strain was identified as Salmonella pullorum. The test results showed there were 9 positive samples of 11 day-old died from natural cause's samples and frozen to die chicken samples, Salmonella isolation rate were 88.9%,100%, respectively. There were 11 positive samples of 18 day-old died of frozen to die samples and Salmonella isolation rate was 72.7%. It was very rare that there was a chicken farm has so highly Salmonella infectious rate, so the chicken farms was proposed to quarantine Salmonella Pullorum and weed out Salmonella pullorum positive chickens, strengthen disinfection to chickens, purify farms.The agglutination antigen of Salmonella pullorum were prepared by bacteria subculture, collection and inactivated, concentrated and optimized the concentration of antigen, sterilized preparation and stained Salmonella pullorum agglutination antigen. The method was established to detect serum antibodies to Salmonella pullorum and the coincidence rate is 91.04% compared with the glass plate agglutination test. It indicated the micro plate agglutination pullorum antigen can be used to detect chicken pullorum serum antibody and it provided the diagnostic antigen for quarantine and clinic diagnosis.