Two novel genetic groups (VIIb and VIII) responsible for recent Newcastle disease outbreaks in Southern Africa, one (VIIb) of which reached Southern Europe

Abstract

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.

Genotyping of Newcastle Disease Viruses Isolated from 2001 to 2007 in Japan

“…The precursor fusion glycoprotein F0 has to be cleaved into F1 and F2 subunits for the progeny virus to be infectious and to be able to replicate in host cells. Based on phylogenetic analysis of the partial nucleotide sequence of F the gene, including the cleavage site, NDV strains have been classified into nine genotypes, I-IX [2,5,12,13,21].…”

Isolation of a Recent Korean Epizootic Strain of Newcastle Disease Virus from Eurasian Scops Owls Affected with Severe Diarrhea

“…Class I viruses are not commonly reported and are found in waterfowl, live bird markets, and domestic poultry (Alexander et al, 1992;Aldous et al, 2003;Seal et al, 2005;Kim et al, 2007). The class II viruses are categorized into genotypes I to IX (Ballagi-Pordany et al, 1996;Lomniczi et al, 1998;Herczeg et al, 1999;Yang et al, 1999;Liu et al, 2003). In Korea, genotype VII first emerged in 1984 and then reemerged in 1995 (Lee et al, 2004).…”

Innovation and discovery: The application of nucleic acid-based technology to avian virus detection and characterization

“…The F gene of NDV is usually, although not exclusively, the focus of attention for universal PCRs, followed by analysis in a number of ways. Herczeg et al (2001) amplified an F gene fragment of 1.3 kb of 36 velogenic strains in Italy and analyzed it with three restriction enzymes, having previously established the existence of several genotypes by this approach (Ballagi-Pordány et al, 1996;Lomniczi et al, 1998;Herczeg et al 1999). Using this approach, and nucleotide sequencing, they were able to link Italian isolates with strains associated with enzootics in various other countries.…”