Development Of Polymerase Chain Reaction To Detect Duck Plague Virus And Study On The Distribution Regularity Of Duck Plague Virulent Strains In Artifical Infected Acutly Adult Duck Body

A Polymerase chain rection (PCR) methold was developed for detecting duck plague virus, We found a 765-EcoR I fragment which cloned from the genome of the duck plague virulent in the GeneBank.The fragment sequence was similar to the 3'ends of an undefined open read frame and the gene for DNA polymerase protein in other herpesviruses. A set of primers were found to be specific for the DP virulent. The specificity was tested with genome templates from other avian herpesviruses, including those from the chichen and the duck, but amplicons were not produced. This PCR test is highly specific for duck plague vaccine strain, equivalent to five genome copies.The PCR can detect 10fg of DNA from the duck plague virulent strain. The test is more 10 times sensitive than tissue culture for detecting duck plague virus. The speed, sensitivity, and specificity of this PCR provide a greatly improved diagnostic and reaction tool for studying the epizootiology of duck plague.In this paper, a pathology model in which DPV were acutly infected was found when Duck Plague virulent, SCI Strains were subcutaneously injected into 56 adult Sichuan ducks,and the Polymerase Chain Reaction(PCR) was used to detect the distribution of DPV in ducks at different time when the clinic symptom and the pathology change in naked eye haved been observed. The ducks was killed when it is 2h, 4h, 6h, 12h, 24h, æ™»?after inoculability for the ducks . and every tissue or organ of infected duck were collected until there was a duck died, then tissue or organ of died duck were collected. The place collected included blood, skin, buccal secretion, heart, liver, spleen, lung, kidney, brain, brisket, esophagus, duodenum, rectum, bursa of fabricius, stomach, dejecta, tongue, thymus, pancreas and medulla, the Polymerase Chain Reaction(PCR) developed above was used to detect the distribution of DPV in every tissue or organ of infected duck at different time. The result indicate that the DPV DNA can be firstly detected 2 hours after inoculability frombrain,liver,spleen,bursa of fabricius,thymus. 4 hours past, the DPV DNA can be detected from heart,liver,spleen, bursa of fabricius ,thymus, pancreas, brain, blood and dejecta. 6 hours past, the DPV DNA can be detected from heart,liver,spleen, lung,kidney, duodenum, rectum, bursa of fabricius ,thymus, pancreas, brain, esophagus, stomach ,blood, tongue , buccal secretion, medulla and dejecta. 12 hours past, the DPV DNA can be detected from heart,liver,spleen, lung,kidney, duodenum, rectum, bursa of fabricius ,thymus, pancreas, brain, brisket, esophagus, stomach ,blood, tongue , buccal secretion, skin ,medulla and dejecta. The tissues which be detected the earliest and the highest efficiency were the liver and brain.The PCR method developed above which can detect differentially and tittlly the DPV DNA strain from clinic sample from tissues or organs of infected duck can be used to detect the duck infected initially. The result of the study will provide significant testing data for illuminating nosogenesis of DPV and detecting DPV by PCR in infected duck body.