高致病性新城疫病毒的分离和生物学特性分析  

Isolation and biological characterization of highly pathogenic Newcastle disease virus

作　　者：吴晓艳 张旭[1] 于天浩 康华裕 张彦龙[1] WU Xiao-yan;ZHANG Xu;YU Tian-hao;KANG Hua-yu;ZHANG Yan-long(College of Wildlife and Protected Area,Northeast Forestry University,Harbin 150040,China)

机构地区：[1]东北林业大学野生动物与自然保护地学院,黑龙江哈尔滨150040

出　　处：《中国预防兽医学报》2024年第9期967-971,共5页Chinese Journal of Preventive Veterinary Medicine

基　　金：应用抗体对产志贺毒素大肠杆菌的保护效果研究(43219024)。

摘　　要：为鉴定导致黑龙江省肇源县2022年某养殖场鸭大量死亡的病原,并分析其生物学特性,本研究将病死鸭组织病料样品处理后接种9日龄SPF鸡胚连续传代分离出病毒后,利用PCR检测临床症状相似的各类禽源病毒,结果显示,除新型新城疫病毒(NDV)外未检测到其他病原。通过测定鸡胚半数致死量(ELD_(50))、平均致死时间(MDT)、1日龄雏鸡脑部致死指数(ICPI)及7日龄雏鸭的感染试验,评估分离株的毒力及致病性;对分离株F基因测序并进行遗传进化分析。结果显示,该病毒株的ELD_(50)为1×10^(-2)ELD_(50)/m L,MDT为58.6 h,ICPI为1.625,致病性试验结果显示,雏鸭全部死亡且解剖发现内脏组织等出现剖检病变;测序结果显示该分离株F基因全长1662 bp,其编码氨基酸裂解位点区序列为^(112)RRQRRF^(117),具有典型强毒力特性;F基因遗传进化树结果显示,该分离病毒属于Class II基因III型,与2000年~2017年在中国家禽中持续流行的病毒株聚为一大分支,且它们F基因序列的一致性为99.8%~99.9%,分离病毒与疫苗株Mukteswar、B1、La Sota、clone30、VG/VA、V4和中国标准嗜内脏速发型强毒株F48E8 F基因的一致性分别为99.6%、88.6%、88.4%、88.6%、88.4%、91.3%、92.1%。本研究为鸭新城疫的防控和疫苗的研制奠定了基础。This study was conducted to investigate the etiology behind the significant duck mortality in Zhaoyuan County,Heilongjiang Province,in 2022,with the goal of establishing a strategy for disease control and prevention.The diseased materials were subjected to virus isolation and inoculated into 9-day-old specific-pathogen-free(SPF)chicken embryos through successive passages,followed by PCR detection for a spectrum of avian viruses.Identification of the isolates were achieved through RT-PCR amplification,hemagglutination inhibition(HI)and hemagglutination assays(HA).The virulence and pathogenicity were evaluated by determining the chicken embryo hemi-lethal dose(ELD_(50)),mean death time(MDT),the lethality index in the 1-day-old chick brain,tapping of7-day-old chick ducks,and F gene sequencing.The findings disclosed the emergence of a novel strain of Newcastle disease virus(NDV)as the culprit behind the high mortality rates in the duck population.This strain exhibited an ELD_(50)of 1×10^(-2)ELD_(50)/m L,an MDT time of 58.6 hours,and an ICPI of 1.625,indicating a highly virulent nature.Pathogenicity tests in chicks led to fatalities,with postmortem examinations revealing lesions in various internal organs and tissues.The F gene sequence of the virus was found to contain 1662 bases,with a cleavage site sequence of^(112)R-R-Q-R-R-R-F^(117),which is characteristic of highly virulent strains.Phylogenetic analysis of the F gene revealed high virulence and pathogenicity.Genetic evolutionary analysis showed the virus belonged to Class II genotype III,clustering with strains circulating in Chinese poultry since 2000,with 99.8%-99.9%nucleotide concordance.Nucleotide concordance with vaccine strains Mukteswar,B1,Lasota,Clone30,VG/VA,V4,and the Chinese standard visceral fast-acting strain F48E8 was 99.6%,88.6%,88.4%,88.6%,88.4%,91.3%,and 92.1%,respectively.This study conclusively identified genotype III Newcastle disease virus as the primary factor causing mass mortality in duck flocks in the region,providing a crucial foundati

关 键 词：新城疫病毒 分离鉴定 Class II基因III型 遗传进化 生物学特性 

分 类 号：S852.65[农业科学—基础兽医学]