Isolation And Identification Of PRRSV In Anhui Area And Study The Effection Of Drugs In Vitro On PRRSV

The Porcine Reproductive and Respiratory Syndrome(PRRS) is a infectious disease caused by porcine reproductive and respiratory syndrome virus(PRRSV).Since the disease broke out first in America in 1987,then it had occurred in many countries.there have took place in june 2006 of anhui area, and this disease has created great damages . The suspect samples of lung, spleen and lymph node collected from the infected herds in Anhui were used for virus isolation identification; two porcine reproductive and respiratory syndrome virus were isolated from the PCR positive samples.The isolates were identified by RT-PCR and IFA test.TCID50 and physico-chemical property was tested on Marc-145 cells. Our data supported that the isolates belong to PRRSV, which designated as JZ08,HS08 respectively.ORF5 and ORF6 genes of two isolate strains were amplified by RT-PCR and cloned into the pMD20-T vector for sequencing. The results of sequence analysis demonstrated that two PRRSV isolates shared 99.2% acids identity of ORF5 and 99.6 % acids identity of ORF6, shared more than 98.3 % and 99.2% acids identity with JXA1,HUN4 strains. The phylogenetic tree established by ORF5 and ORF6 know that these two PRRSV Strains has the genetic distance . Then it indicated that the Chinese isolates could be divided into two subgroups:Ch-1a,JXA1,HUN4 and some other strains fall into a subgroup ;VR-2332, BJ-4 belonged to other subgroup.The two isolate strains with JXA1,HUN4 of PRRSV strains evolved from the same strain, belong to the American type; From the two isolate strains of ORF5 and ORF6 gene sequence analysis result, we can see the ORF5 gene isolated in a number of nucleotide sites is more than ORF6 gene nucleotide sites. , which suggested that they belong to North American typeAPS,RBV,ABOB,Amantadine and IFN were adopted as antiviral drugs to evaluate the inhibitive effect of three drugs to PRRSV in vitro by the MTT and CPE assay when vi- rus invading Mark-145 cell before adding medicine,adding medicine before invading virus and invading virus with adding medicine at the same time. The result show that the OD va- lue of RBV,ABOB,Amantadine group was significantly different from virus control group, so RBV,ABOB,Amantadine had better effects inhibited the virus replicationg in Marl-145 cell, APS,IFN had feeble effects; IFN,APS and Amantadine had obviously blocking effect on PRRSV in vitro ; RBV Amantadine had obvious direct kill the virus role, Other Medicine had feeble effects Only at higher concentrations .