| Porcine reproductive and respiratory syndrome,which is characterized by abortion,prematu -rity and fetal death of sows and respiratory distress disease of piglets and growing pigs,is a highly infectious disease caused by porcine reproductive and respiratory syndrome virus(PRRSV).'high fever disease outbreaks in many farms in china,causing great economic loses to swine raisi -ng,2006.It is verified that the main pathogen is highlypathogenic PRRSV(HP-PRRSV).HP -PR RSV is grouped into typeⅡand have adiscontinuous deletion of 30 amino acids in nonstructur al protein 2(NSP2).Pathogen analysis showed by RT PCR that HP-PRRS occurred frequently in Chongqing and its surrounding regions in December 2006,the transmission of disease reached to peak in May 2007. HP-PRRS has been Contained when pigs were injected with inactivated vaccine from June.We had done research about the actual prevalence of HP-PRRS in the region,the results as following:1 Pigs of 31farms infected "Fever of Unknown" in 19 areas of Lu Xian,ZiGong,NiJiang QuXian XiChang,DaZhu,QianWei,YiBin of SiChuan province and RongChang,DaZu,ChangShou, TongLiang,HeChuan,BaNan,BiShan,ZhongXian,YuBei,KaiXian of Chong Qing were investigated in this study.The result showed clinical symptoms and pathological lesion were the same as HP-PPRRS.238 samples were made of The blood serum,lung,spleen and lymph node of infected pigs were tested by RT PCR,the result showed that 134 samples were positive.Positive rate was 56.3%,Positive rate of SiChuan province was 54.9%while it was 59.6%in ChongQing.QX,YB, RC,QW,and LSwere purified by gel recovery,they were were cloned into PU Cm-T vector,the ligation production were transferred it into DH5αand the obtained clones were amplified and cultured,then sent them to Sangon to sequence determination,nucleotide sequence of QX,YB,RC and LS were the same,compared with JXA1,the sequence homologous rates of nucleotide were 96%,while QW was compared with JXA1,the sequence homologous rates of nucleotide were 98%,these proved QW and JXA 1 had closeiy genetic relationship.In conclusion,the HP-PRRSV is really the predominant causative agent of disease in ChongQing and SiChuan by the clinical,patho -logical observations of pigs and the sequence Compared with JXA1.2 In order to find relationship between IL-1 TNF-αcontent in blood serum and temperature of pigs are infected with HP-PRRSV,20 blood serum samples that were from 43 positive samples of HP-PRRSV were test on IL-1,TNF-α.The 43 positive samples were collect from 4 pig farms that have been outbreaks of disease.The results were that IL-1,TNF-α.and temperature were not related, 14 samples were higher than 100 pg/mL on IL-1 while 6 samples were lower than 100 pg/mL,5 samples were higher than 100 pg/mL on TNFαwhile 15 samples were lower than 100 pg/mL.34 blood serum samples that were negative samples of HP-PRRSV were test on IL-1,TNF-α.The 34 positive samples were collect from 3 pig farms that have not been outbreaks of disease.The results were that 9 samples were higher than 100 pg/mL on IL-1 while 32 samples were lower than 100 pg/mL,10 samples were higher than 100 pg/mL on TNF-αwhile 31 samples were lower than 100 pg/mL.7 blood serum samples that were positive samples of HP-PRRSV were test on IL-1,TNF-α.The 7 positive samples were collect from 2 pig farms that have not been outbreaks of disease.The results were that 2 samples were higher than 100 pg/mL on IL-1 while 5 samples were lower than 100 pg/mL,1 sample were higher than 100 pg/mL on TNF-αwhile 6 samples were lower than 100 pg/mL.IL-1 content of pigs that were positive by HP-PRRSV RT-PCR with significant chracters,without chracters and control were 298±57 pg/mL,154±109 pg/mL,97±32 pg/mL,TNF-αcontent of pigs that were positive by HP-PRRSV RT-PCR with significant chracters, without chracters and control were74±23 pg/mL,52±29 pg/mL,77±13 pg/mL.The results show IL-1 content of pigs that were positive by HP-PRRSV RT-PCR with significant chracters significant upregulation as compared to the other two groups.IL-1,TNF-αon the others groups were not significant upregulation.These results suggest that IL-1 was incread in blood Serum when pigs were infected by HP-PRRSV while TNF-αhas little change.3 339 pigs that were infected by HP-PRRSV form 4 farms were treated using Asperin and Timicosin that may play an important role to inhibit the synthesis of proinflammatory cytokines in the level of transcription and translation for IL-1 and TNF-α,the result was that 271 pigs cured,The cure rate was 79.4%,5 sick pigs in the treatment of hair before 3 days after treatment,6 days,9 days,respectively,for IL-1 and TNF-αdynamic quantitative monitoring the result was that IL-1 levels in 9 days after treatment decreased significantly,TNF-αdid not change significantly during treatment,it indicate that aspirin an tilmicosin or florfenicol combination may have a certain effect to HP-PRRSV.
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