【摘要】 从发病鸡场中收集的腺胃肿大病料(编号为2/97、3/97和1/98),经匀浆和无菌处理后在SPF鸡胚中传代、分离和鉴定。结果显示,接种病料培养的鸡胚可干扰新城疫病毒的复制;这些分离毒株可与阳性标准参考株IBV抗血清反应,但表现出较低的中和反应能力。在理化和血凝特性等鉴定的基础上,参照已发表的IBV Beaudette毒株S1基因序列,设计并合成1对含有EcoRⅠ和BamHⅠ酶切位点的特异性引物,利用RT-PCR技术扩增到分离毒株3/97、2/97、1/98长度为1.93kb的cDNA片段,并将其cDNA片段插入到克隆载体pBlueScript-SK(+)中,进行核苷酸序列的测定,确证所扩增和克隆的cDNA片段由1930个碱基组成,并编码1条由620个氨基酸组成的多肽。与GenBank中其它IBV S1基因序列进行比较,发现3/97、2/97和1/98毒株与所比较的IBV毒株核苷酸的一致性为73.6％～99.7％,氨基酸的一致性为78.4％～99.7％。更多还原

【Abstract】 Swollen proventriculi were collected, homogenized and purified. Suspected virus sample was adapted in SPF chicken embryos for viral isolation and identification. The virus had several biological characteristics similar to IBV by agglutinating red blood cells after treatment with trypsin. It also interfered with the reproduction of Newcastle disease virus in chicken embryos. Virus isolates also exhibited lower specific neutralizing reaction with reference positive IBV an-tiserum. The physiochemical properties were also detected in this research. On the other hand, proventriculus-pathogenic Infectious Bronchitis Virus 3/97, 2/97, 1/98 RNAs extracted from the allantoic fluid of inoculated embryonated eggs was converted to cDNA by reverse transcription with 3’-primer. Amplified product of 1.93 kb was subjected to EcoR I and BamH I digestion and the fragments obtained were the same as expected. Polymerase chain reaction was performed with two primers which span the SI gene. The PCR product was ligated to pBlueScript-SK ( + ) vector, and its nucleotide sequence was determined by the dideoxy-mediated chain termination method. A comparison of the nucleotide sequence with that of other IBV strains in GenBank showed that the homology was between 73.6% - 99.7 % . The homology of AA was between 78.4 % ~ 99.7 % .更多还原