Genetic characterization of varicella zoster virus in Jilin province in 2014, China

Abstract

To clarify the genotype of wild-type strains of varicella zoster virus (VZV) in Jilin province in 2014, and to discriminate between v-Oka vaccine strains and wild-type strains. Vesicle fluid and throat swab samples were collected from 13 individuals with suspected VZV in Jilin province from January to December 2014. Viral DNA was extracted, the fragments of 15 open reading fragments (ORFs) were amplified by polymerase chain reaction (PCR), and viral genotypes were determined by single nucleotide polymorphisms (SNP). PCR restriction fragment length polymorphism (RFLP) was used to distinguish between wild-type strains and v-Oka vaccine strains. The results were analyzed with MEGA5 software, using the VZV reference strain sequences from GenBank. The 13 suspected samples included 5 males and 8 females, aged 11-27 years (mean: (16.69±5.48) years). Sampling was performed on days 0 to 3 of suspected infection. VZV strains were detected in 8 samples, all belonging to Clade 2. There was a synonymous mutation (T>C) in SNP18082 compared with the v-Oka vaccine strain. Analysis of PCR-RFLPs showed that all 8 positive samples were wild-type strains (PstⅠ(+)BglⅠ(+)SmaⅠ(-)). The study revealed that the VZV strains circulating in Jilin province in 2014 were wild-type strains belonging to Clade 2.