【摘要】 为研究鸡传染性法氏囊病病毒(IBDV)3个不同亚群B节段对病毒致病性的影响,本实验将IBDV HLJ0504超强毒株的A节段分别与3个亚群(Ⅰ亚群Gt株、Ⅱ亚群HLJ0504株及Ⅲ亚群HuB-1株)B节段进行组合,拯救了rH4AGtB、rH4AH4B和rH4AHuB3种重组病毒。动物实验结果表明,rH4AHuB引起雏鸡死亡率为80%、rH4AH4B次之为73.3%、rH4AGtB仅为33.3%。此外,rH4AHuB在体内复制的能力明显高于rH4AGtB(p<0.05),但与rH4AH4B无明显差异(p>0.05)。以上结果表明,IBDV B节段影响病毒的致病性,不同亚群B节段对IBDV致病性的影响作用不同。其中,第II、III亚群的B节段能够提高病毒在体内的复制能力,从而使IBDV的致病性增强,而第I亚群的B节段则降低了病毒在体内的复制能力,使IBDV的致病性减弱。更多还原

【Abstract】 To study the impact of different subgroups of segment B on the virulence of infectious bursal disease virus(IBDV),three recombinant IBDVs, named rH4 AGtB, rH4AH4 B and rH4 AHuB were rescued by using the reverse genetic system which contained the segment A from vvIBDV strain HLJ0504 and the segments B from different subgroup strains(attenuated Gt strain of subgroup I, vvIBDV HLJ0504 strain of subgroup II, and vvIBDV HuB-1 strain of subgroup III). The pathogenicity test results showed that the rH4 AHuB caused a mortality of 80% which was higher than that of rH4AH4B(73.3%). The rH4 AGtB containing the attenuated segment B caused the lowest mortality of 33.3%. The viral loads of rH4 AHuB in the bursal of infected chickens were significantly higher than that of rH4AGtB(p<0.05), but no significant difference with rH4AH4B(p>0.05). These results indicated that the different subgroups of segment B showed an impact on the viral virulence. The segment B from II and III subgroups had a positive effect on the viral replication and virulence in vivo, while the segment B from the subgroup I attenuated strains showed a negative effect on the viral replication and virulence.更多还原