VZV Foundation - A Decade Of Leadership In The Fight Against VZV Infections

	Oral Presentation Abstracts: 15 [15] GENETIC VARIATION OF VARICELLA ZOSTER VIRUS *Winsome Y. Barrett-Muir (1), Richard Nicholls (2), Mansoor Saki(1), Judith Breuer (1) Schools of Medicine (1) and Biological Sciences (2), Queen Mary College, University of London, 37 Ashfield St, London E1 1BB, UK To date VZV strains has been typed based on a limited number of polymorphisms in restriction endonuclease sites. However little is known about genetic relationships between different strains. We have developed a more extensive polymorphic map of the VZV genome based on Heteroduplex mobility assay (HMA) and nucleotide sequencing. This was used to identify variants of Varicella zoster virus (VZV) circulating in the UK and elsewhere. In the initial 10 samples used to generate the polymorphic map 131 base substitutions out of 232,660 examined were found, giving an overall variation of 0.061%. These variations were observed at 40 nucleotide positions. Sixteen substitutions were non-synonymous resulting in an amino acid change, the majority of which were clustered within surface expressed proteins. Phylogenetic analysis distinguished at least four genetic strains, A, B, C and D and the branching order was verified by high values on bootstrap analysis. Each genotype showed distinct geographical distribution; some were highly restricted whereas others were more widespread. Many areas were populated by one genotype, although a mixture of genotypes were found in the UK and Brazil, possibly reflecting recent population movements. Allelic co-segregation of widely spaced single nucleotide polymorphisms suggested a low rate of recombination. However, one A/C recombinant was found originating from Brazil where mixtures of genotypes circulate. These findings may increase our understanding of VZV epidemiology and provide a basis for investigating possible biological variation in VZV strains. Corresponding Author: Judith Breuer, MD, Reader in Virology, Department of Medical Microbiology, St.Bartholomew's and the Royal London School of Medicine and Dentistry, 37Ashfield Street, London E1 1BB, United Kingdom

[15]

GENETIC VARIATION OF VARICELLA ZOSTER VIRUS

*Winsome Y. Barrett-Muir (1), Richard Nicholls (2), Mansoor Saki(1), Judith Breuer (1) Schools of Medicine (1) and Biological Sciences (2), Queen Mary College, University of London, 37 Ashfield St, London E1 1BB, UK

To date VZV strains has been typed based on a limited number of polymorphisms in restriction endonuclease sites. However little is known about genetic relationships between different strains. We have developed a more extensive polymorphic map of the VZV genome based on Heteroduplex mobility assay (HMA) and nucleotide sequencing. This was used to identify variants of Varicella zoster virus (VZV) circulating in the UK and elsewhere. In the initial 10 samples used to generate the polymorphic map 131 base substitutions out of 232,660 examined were found, giving an overall variation of 0.061%. These variations were observed at 40 nucleotide positions. Sixteen substitutions were non-synonymous resulting in an amino acid change, the majority of which were clustered within surface expressed proteins.
Phylogenetic analysis distinguished at least four genetic strains, A, B, C and D and the branching order was verified by high values on bootstrap analysis. Each genotype showed distinct geographical distribution; some were highly restricted whereas others were more widespread. Many areas were populated by one genotype, although a mixture of genotypes were found in the UK and Brazil, possibly reflecting recent population movements. Allelic co-segregation of widely spaced single nucleotide polymorphisms suggested a low rate of recombination. However, one A/C recombinant was found originating from Brazil where mixtures of genotypes circulate.
These findings may increase our understanding of VZV epidemiology and provide a basis for investigating possible biological variation in VZV strains.

Corresponding Author: Judith Breuer, MD, Reader in Virology, Department of Medical Microbiology, St.Bartholomew's and the Royal London School of Medicine and Dentistry, 37Ashfield Street, London E1 1BB, United Kingdom