| Classical swine fever(CSF), caused by Classical swine fever virus (CSFV),is a highly contagious disease of pigs, and one of OIE Listed diseases, In recent years, CSF caused great economic losses in pork industry. CSFV, together with Bovine viral diarrhea virus 1(BVDV-1), BVDV-2 and Border disease virus(BDV),belongs to the genus Pestivirus within the family Flaviviridae.Pigs can be infected with almost any pestivirus species.It is rather difficult to differentiate CSFV from other pestiviruses by conventional serological tests due to cross-reactivity.The Primary Method to prevent swine fever is vaccination.It play an important role in preventing swine fever to popular the C-strain vaccine. But we also meet some more problem when we distinguish the pig infected by wild-type virus and pig to get vaccinated in traditional way. At present, the quality of C-strain vaccine has a significant reduction because of the reduction of rabbit which is integrant for manufacture.It is difficult to get the vaccine's standard quality .The scheduled titer standard is only as more as the 1/3 of foreign standatds, the lowest titer, if we run as the instructions,the immune effect can not be effectful enough. In order to understand the titer of the C-strain vaccine commonly used by different manufacturers in different place in the current market, we establish the method to detect CSFV and complete primary estimation.The amplified results of sixteen vaccines come from different datchs on different manufactures, exist great difference.There was about 1/3vaccines that their titers were lower.That could result in immune-failure after inoculation with those vaccines.It was bad for effective protection from CSFV. Moreover, these vaccines existed great titer difference and qualites of different datch were not stable.Contrasting with 34 strains CSFV genomic sequences of pestiviruses available in GenBank. A pair of primers was designed in the A1 region of E2 gene which based on the sequence of the CSFVgenomes(AY805221),and the RT-PCR to detect CSFV was developed. The 276bp specifical fragment was obtained from the CSFV vaccine strain RNA by RT-PCR while it was not obtained from PRV, PPV, PCV-2. The pathogenic detection of CSFV in clinic suspected samples colleted from Xinxiang , Zhoukou, Jiaozuo of Henan province was carried out by the RT-PCR . The 276bp specifical fragment was obtained from all of the sample above,and it coule be digested into two segments of 83bp and 193bp by Hinfâ… .On the basis of the RT - PCR, through contrasting with 34 strains CSFV genomic sequences of pestiviruses available in GenBank.. CSFV specific primers for the differentiation of wild-type viruses from C-strain vaccine strain were designed in the genetic diversity of the 5'-UTR of CSFV. The mutiplex differential diagnosis PCR which was sensitive,specifical, and good repeatability can differentiate wild-type viruses from C-strain vaccine .Acute classical swine fever and African swine fever are characterized by hemorrhages and can be easily confused with each other. Over the past two years, there have been in Georgia, Russia, the Chechen Republic, Zambia, Azerbaijan, Tanzania and other countries outbreak of African swine fever. Although currently there is no ASF infected in china , but neighboring countries as Russia, we have always been affected by ASF possibly, the timely investigation of ASF diagnosis and real-time monitoring is particularly important significance. ASF to timely investigation of the possibility of infection, the study design of the experiment, the distinction between wild-type viruses and C-strain vaccine based on the PCR method was established, and triple PCR method distinction between wild-type viruses and C-strain vaccine at the same time, simple and efficient real-time monitoring of the African Swine Fever Epidemic in China. Experimental investigation results show that around the classical swine fever in Henan Province at present despite continuous, but not the existence of ASF infection.
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