Simultaneous Cocirculation of Both European Varicella-Zoster Virus Genotypes (E1 and E2) in Mexico City

Abstract

Full-length genome analysis of varicella-zoster virus (VZV) has shown that viral strains can be classified into seven different genotypes: European (E), Mosaic (M), and Japanese (J), and the E and M genotypes can be further subclassified into E1, E2, and M1 through 4, respectively. The distribution of the main VZV genotypes in Mexico was described earlier, demonstrating the predominance of E genotype, although other genotypes (M1 and M4) were also identified. However, no information regarding the circulation of either E genotype in the country is available. In the present study, we confirm the presence of both E1 and E2 genotypes in the country and explore the possibility of coinfection as the triggering factor for increased virulence among severe cases. A total of 61 different European VZV isolates collected in the Mexico City metropolitan area from 2005 to 2006 were typed by using a PCR method based on genotype-specific primer amplification. Fifty isolates belonged to the E1 genotype, and the eleven remaining samples were classified as E2 genotypes. No coinfection with both E genotypes was identified among these specimens. We provide here new information on the distribution of VZV genotypes circulating in Mexico City.

Specific Detection of Naturally Occurring Hepatitis C Virus Mutants with Resistance to Telaprevir and Boceprevir (Protease Inhibitors) among Treatment-Naïve Infected Individuals

“…Our group has successfully designed several methods based on MAMA PCR for the identification of different SNPs in multiple settings (9,23). Using this approach, we designed MAMA PCR primers for the identification of the known drug-resistant HCV mutants.…”

“…Two different approaches were used to confirm the presence of the corresponding mutants in these clinical samples. First, an adaptation of the endpoint limiting dilution protocol was used to assess the intrahost variation in the NS3 region (23). Multiple PCR clones (30,37,45, and 32 for patients 1, 2, 3, and 4, respectively) were identified and sequenced.…”

“…Analysis of the intrahost viral population was assessed by using an adaptation of our previously reported method (23). Briefly, cDNA synthesis was performed as mentioned above.…”

“…However, in the absence of selective pressure (antiviral therapy), HCV variants bearing mutations conferring resistance are generally present at a very low frequency within the viral population, making mutation detection extremely challenging. Mismatch amplification mutation assay (MAMA) PCR is a sensitive methodology that has been widely used for the detection of single nucleotide polymorphisms (SNPs) in a variety of settings (6,23).…”

Interleukin-28B Genotyping by Melt-Mismatch Amplification Mutation Assay PCR Analysis Using Single Nucleotide Polymorphisms rs12979860 and rs8099917, a Useful Tool for Prediction of Therapy Response in Hepatitis C Patients

“…MAMA-PCR has been largely used for timely nucleotide substitution identification in diverse settings (3,11,15). The combination of MC analysis resolution and the simplicity of MAMA-PCR-based assays provides a powerful tool for the accurate identification of SNPs without the need for extra steps after DNA amplification (13).…”