高抗体水平种鸡NDV的分离鉴定和分子特性

Isolation,Identification and Molecular Characterization of a Velogenic NDV Isolate from a Broiler Flock in High Antibody Level Against NDV

摘要:

从抗体水平较高、产蛋下降的种鸡群分离到一株新城疫病毒(Newcastle Disease virus,NDV)SGM01,经动物回归可产生NDV典型病变,其MDT、ICPI和IVPI等分别为50．5h、1．76和2．41,表明为强毒。对其F和HN基因进行克隆测序,F基因氨基酸多肽裂解位点的基序为~(111)GRRQKRF~(117),与强毒基序一致。基因分型表明SGMO1属Ⅶ型。氨基酸同源比较显示:SGM01与LaSota、SQZ04等基因Ⅱ型的同源性为:87．7%～88．3%;(?) Taiwan95、Yunnan03等基因Ⅶ型的同源性为:95．7%～98．2%;与F₄₈E₉等基因Ⅸ型的同源率为:90．8%～91．7%。HN基因与F基因不同,具有明显的时空性。SGM01、Taiwan95、SQZ04等新近分离毒氨基酸高度同源,同源性为:95．3%～97．2%,显著高于与LaSota(经典弱毒疫苗株)和F₄₈E₉(经典强毒株)的同源性87．4%～89．0%。

Abstract:

A Newcastle disease virus(NDV)field strain SGM01 was isolated from a broiler flock in high antibody level against NDV,and identified by HA,HI cross test and animal regression.SGM01 was determined as a virulent strain with MDT of 50.5h,ICPI of 1.76,IVPI of 2.41 after plaque-purification.The F and HN gene of SGM01 were cloned and sequenced.Analysis of F gene indicated that SGMOI be- longed to genotypeⅦ.The amino acid sequence ¹¹¹GGRQGRL¹¹⁷ in the F protein cleavage site in SGM01 strain is identical to virulent NDV.The homology analysis of F and HN gene sequences compared to reference stains from GenBank indicated that:The F protein amino acid se-quence has homologies of 87.7%～88.3% with published gene type Ⅱ strains LaSota and SQZ04 et al.,95.7%～98.2% with genotype Ⅶ strains Taiwan95、Yunnan03 et al., 91.8%～91.7% with genotype Ⅸ strains F₄₈E₉et al., While HN genes were compared,SGM01 demonstrated a higher homologies of 96.5%～97.2% with strains which were isolated in recent years,but lower homologies of 87.4% and 89.0% with LaSota and F₄₈E₉.