Genetic Analysis of Clinical VZV Isolates Collected in China Reveals a More Homologous Profile

Longfeng Jiang,Lin Gan,Mingli Wang,Jason Chen

doi:10.1155/2013/681234

Longfeng Jiang, Lin Gan + Show 2 more

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https://doi.org/10.1155/2013/681234

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Abstract

Forty-four varicella-zoster virus (VZV) isolates from China were genotyped by using a scattered single nucleotide polymorphism (SNP) method, including open reading frames (ORFs) 1, 22, 31, 37, 60, 62, 67, and 68. Based on the analysis of the polymorphic markers in the 8 ORFs, all of the 44 isolates can be placed in genotype J defined by the SNP profiles in ORF22 or clade B defined by the SNP profiles in ORFs 31, 37, 60, 62, 67, and 68. The three consecutive nucleotide (CGG) in-frame insertions in ORF 1 were found in 8 (18.2%) isolates, which has not been described in VZV strains from any other part of the world. A novel synonymous A>G substitution in ORF60 was revealed in 4 (9.1%) of the isolates. In addition, a previously described three consecutive nucleotide (ATC) insertion in ORF 60 was found in all the Chinese isolates but not in the US isolate MLS. The results showed all the 44 strains that belong to genotype J/clade B with significantly high homogeneity, and phylogenetic analysis suggested that the 44 Chinese isolates consist of 4 clusters, but interstrain variations also exist. Overall, VZV isolates obtained in China showed significantly higher genetic homogeneity than isolates reported from other countries.

Highlights

Varicella-zoster virus (VZV) is a member of the genus Varicellovirus within the subfamily of Alphaherpesvirinae, family of Herpesviridae
The three consecutive nucleotide (CGG) in-frame insertions in open reading frames (ORFs) 1 were found in 8 (18.2%) isolates, which has not been described in VZV strains from any other part of the world
According to the nomenclature scheme proposed by Faga et al [7], the 44 isolates could be assigned to clade B/clade 2 by analysis of single nucleotide polymorphism (SNP) in VZV ORFs 31, 37, 60, 62, 67, and 68 (Figure 2)

Summary

Introduction

Varicella-zoster virus (VZV) is a member of the genus Varicellovirus within the subfamily of Alphaherpesvirinae, family of Herpesviridae. Varicella occurs after the initial encounter with VZV, during which a lifelong latent infection is established. Latent virus can be reactivated, usually decades later in life, to cause zoster [1]. It is a nearly ubiquitous pathogen that affects all human populations. The epidemiology of VZV infection varies geographically [2]. Most children have a primary VZV infection at school ages, whereas in tropical countries primary infection is often delayed until adulthood. In China, the epidemiology of varicella appears to be typical of temperate climate regions

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