Genetic variation of varicella-zoster virus strains circulating in Mexico City

Abstract 

Background

Different studies regarding VZV genotype distribution worldwide have demonstrated that genetic diversity and epidemiology of infection significantly vary from region to region. In Mexico, VZV genotype distribution is largely unknown mostly due to the lack of a surveillance system that monitors accurately the presence of viral strains circulating in the country.

Objective

To identify the main VZV genotypes circulating in the metropolitan area of Mexico City.

Study design

In this study, 127 different VZV isolates, obtained from residents of the Mexico City Metropolitan area from 2005 to 2008, were identified and genotyped. Viral detection and preliminary genotyping was performed by amplification of the VZV ORF-38 and -54 and RFLP analysis using PstI and BglI endonuclease restriction patterns, respectively. Genotype was confirmed by nucleotide sequence variation along the ORF-22.

Results

RFLP analysis classified 121 viral strains as European and 6 as mosaic genotype. Genotyping scheme based on the ORF-22 sequence variation identified 120 viral strains belonging to the E genotype, 6 M1 and 1 M4 genotype strains.

Conclusions

VZV European genotype appears to predominate in Mexico City. This is the first study addressing VZV genotype distribution in Mexico. The information reported in this paper may be useful for future epidemiological studies conducted in the country and also contributes to understand better the molecular epidemiology of VZV in the Americas.

Abbreviations: VZV, varicella-zoster virus, PCR, polymerase chain reaction, RFLP, restriction fragment length polymorphism, ORF, open reading frame, SNP, single nucleotide polymorphism, DNA, deoxyribonucleic acid, E, European, M, mosaic, J, Japanese

Keywords: Varicella, Mexico, Genotyping, Molecular epidemiology