Two novel genetic groups (VIIb and VIII) responsible for recent Newcastle disease outbreaks in Southern Africa, one (VIIb) of which reached Southern Europe
Two novel genetic groups (VIIb and VIII) responsible for recent Newcastle disease outbreaks in Southern Africa, one (VIIb) of which reached Southern Europe
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DOI：
10.1007/s007050050624
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发表时间：
1999-01-01
影响因子：
2.7
通讯作者：
Lomniczi, B
中科院分区：
文献类型：
--
作者：
Herczeg, J;Wehmann, E;Lomniczi, B
用限制性内切酶和融合蛋白基因部分序列分析方法对1990 - 1995年在南非共和国和莫桑比克以及1995-1997年在保加利亚和土耳其分离的34株新城疫病毒（NDV）进行了鉴定。南部非洲的大多数分离株以及来自保加利亚和土耳其的分离株被归入一个新的类群，称为VIIb。VIIb群是一个更大的遗传群（VII）的一部分，其中还包括来自远东和一些西欧国家的NDV毒株（VIIa）。基因型VIIa和基因型VIIb病毒之间的遗传距离为7- 8.5%，排除了最近的南部非洲动物流行病与20世纪90年代西欧或远东暴发之间存在直接流行病学联系。另一种迄今未记录的基因型（VIII）也在南非被发现，其假定祖先成员的后代在20世纪60年代被分离出来。最近的VIII群毒株与主要动物流行病基因型（VIIb）的遗传距离超过11%，因此它们引起的疫情在流行病学上不相关。在过去的几十年里，基因型VIII病毒一定是通过地方性感染在南非维持的，而基因型vii病毒似乎是最近才引入的。
34 strains of Newcastle disease virus (NDV) isolated during epizootics in the Republic of South Africa and in Mozambique between 1990 and 1995, and in Bulgaria and Turkey in 1995-1997 were identified by restriction enzyme and partial sequence analysis of the fusion (F) protein gene. The majority of isolates in southern Africa and those from Bulgaria and Turkey were placed into a novel group which has been termed VIIb. Group VIIb is part of a larger genetic cluster (VII) that also includes NDV strains from the Far East and some western European countries (VIIa). The genetic distance of 7-8, 5 % between genotype VIIa and VIIb viruses excludes the existence of a direct epidemiological link between recent southern African epizootics and outbreaks in either western Europe in the 1990's or those of the Far East. Another hitherto unrecorded genotype (VIII) was also found in South Africa with descendants of putative ancestral members isolated in the 1960's. The genetic distance of recent group VIII strains from the major epizootic genotype (VIIb) is over 11%, therefore outbreaks caused by them were epidemiologically unrelated. Genotype VIII viruses must have been maintained in South Africa by endemic infections during the past decades while group VIIb appears to be introduced more recently.