Shingles Research Today is a free monthly online journal that collates and summarizes the latest research about Shingles, including details on symptoms, treatment, causes, virus.

Genotyping of varicella-zoster virus and the discrimination of Oka vaccine strains by TaqMan real-time PCR.

Parker SP, Quinlivan M, Taha Y, Breuer J

Skin Virus Laboratory, Centre for Infectious Disease, Institute of Cell and Molecular Science, Barts and the London school of Medicine and Dentistry, 4 Newark St., London E1 2AT, England.

Single nucleotide polymorphisms (SNPs) in five genes have been used to identify four major subtypes of wild-type varicella-zoster virus (VZV) A, B, C, and J. Additional SNPs, located in the IE62 major transactivating gene can be used to differentiate the Oka vaccine strain (vOka) from wild-type VZV. Primer-probe sets for the detection of the five polymorphic loci were designed by Applied Biosystems for the ABI 7900HT platform. Probes for each allele were labeled with VIC or 6-carboxyfluorescein fluorogenic markers. Each primer-probe set was validated to establish assay sensitivity and specificity using VZV DNA of predetermined copy number and genotype. Further evaluation was carried out using DNA samples from the vesicle fluid or skin swab of the rash of adult patients with herpes zoster or rashes due to vOka. Assay sensitivity ranged from 10 and 10(8) copies/ml of VZV DNA (equivalent to 2 to 20 copies per reaction). Statistical analyses showed that for each genotype, a set of two probes clearly differentiated the nucleotide present (allele) at that locus (P < 0.0001). It was possible to determine the genotype of wild-type VZV using one of four SNP assays and also to differentiate wild type from vOka using a single SNP assay. The assay can be used for diagnostic and epidemiological studies of VZV, including the differentiation of vOka from wild-type strains, investigation of breakthrough infections, and varicella outbreaks following immunization.

Published 7 November 2006 in J Clin Microbiol, 44(11): 3911-4.
Full-text of this article is available online (may require subscription).

© 2005-2008 Shingles Research Today. All Rights Reserved.