Study On Effects Of Drugs To Several Strains Of NDV

Newcastle Disease is a kind of acute and highly contagious diseases caused byNDV. NDV can invade many kinds of birds, It has a high mortality rate seriously endangered the poultry industry. In recent years, typical NDV have not been outbreaked widely by using NDV vaccine. But untypical ND was caused by vaccinating failure usually due to factors of body internal, vaccine, antibody of maternal, and all kinds of immunize-suppressed factors, misuse of antiviral drugs. The study intend to screen the medicine with better immunoenhancement from various kinds of drugs, and screen high sensitivity medicines and composites to NDV in vitro and vivo test. The study reaserch the way of anti-virus systematically, provid scientific theory for prevention and cure ND.The study adopts nine kinds of antiviral drugs and six strains of NDV: Ribavirin, Moroxydine, Astragalus polysaccharides (ASP), Interferon, Polyl-C, Phytohemagglutinin (PHA),Thymicpeptide, Acyclovir, Shuanghuanglian. F₄₈E₉, HBG-1, HT-40, Lasota, C30, ND-1 . The CPE inhaibition test was to detect the sensitivity of nine antiviral drugs to NDV. The CEF cellular activity was tested by Neutral Red Assay to evaluate the effect of nine drugs to NDV when virus invading and reproducting in CEF,and the effect of direct resisting virus .The result showed that ASP, Poly I-C, interferon, Ribavirin, PHA, Thymic peptide inhibited the virus invadeing cell significantly, Ribavirin, PHA, Poly I-C, ASP, Shuagnhuanglian Acyclovir had better effects inhibited the virus replication in CEF, but Moroxydine, Thymic peptide,Interferon had feeble effects, and all the nine kinds of medicines could kill NDV directly. Three complex composites were composed according to the ways of anti-virus by two of these efficiency drugs ASP, PHA, Poly I-C, Ribavirin, Interferon. The three complex composites were : ASP and Ribavirin, PHA and Ribavirin, Interferon and Poly I-C.The maximum non-toxic concentration of the three composites were tested in CEF and then the sensitivity of anti-NDV was detected by the way to single medicine.The result showed that the three composites had stronger anti-NDV in CEF than other single medicines.In order to sceen the medicine with better immunoenhancement, the study evaluates nine drugs effects to the antibody level in different times after inoculated ND-VI,C30, ND-1 in three ways :the first was inoculating medicine before inoculating vaccine, the second was inoculating medicine after inoculating vaccine,the third was inoculating medicine and vaccine in the same time.The result showed that ASP,PHA, Thymic peptide can enhance the immunization , the time of antibody production was ahead of schedule and the high antibody was maintained longer. But the other six drugs influenced the antibody ascending severity.The result of drug prophylaxis and therapeutic test showed that Ribavirin, ASP, Interferon, Poly I-C,Shuanghuanglian and three composites had better prevention effects to ND. Prophylaxis protection rate was 33.3%, 20%, 73.3%, 93.3%, 20%, 80%, 33.3%, 100%, 100%, 100%. Ribavirin,ASP,PolyI-C,PHA, Shuanghuanglian and three composites had better therapeutical effects to ND . Cure rate was 20%, 40%, 33.3%, 40%, 20%, 60%, 63.3%, 60%. It was proved that the composite was better than single medicine.