Multiple recombinants in two dengue virus, serotype-2 isolates from patients from Oaxaca, Mexico

Area of Science:

• Virology
• Molecular Biology
• Epidemiology

Background:

• Dengue virus (DENV) is a significant global health concern, endemic in Mexico, with Oaxaca reporting high case rates.
• DENV's rapid evolution, driven by mutation and potential recombination, contributes to immune evasion and altered host tropism.
• Recombination in Mexican DENV strains and its evolutionary impact in endemic regions like Oaxaca, where all four serotypes circulate, remained uncharacterized.

Purpose of the Study:

• To investigate the presence and extent of genetic recombination in dengue virus (DENV) isolates from Oaxaca, Mexico.
• To analyze the evolutionary implications of DENV recombination in an endemic region with diverse serotype circulation.

Main Methods:

• Sequencing of six DENV-2 isolates from Oaxaca (2005-6 outbreak) and specific gene clones.
• Utilized RDP3 and GARD software, alongside other methods, to detect evidence of viral recombination.

Main Results:

• Evidence of recombination was identified in DENV isolates from Oaxaca, Mexico.
• Specific isolates (MEX_OAX_1656_05 and MEX_OAX_1038_05) were confirmed as recombinant, incorporating sequences from the Cosmopolitan genotype.
• A clone of the E gene (MEX_OAX_165607_05) also showed recombinant characteristics, with genome sequence from the American genotype.

Conclusions:

• This study provides the first report of recombination in DENV-2 within Mexico.
• Detected recombinant activity generates novel genomic combinations, significantly impacting DENV evolution and genetic diversity.
• Understanding DENV recombination is critical for the development of future vaccines and antiviral therapies, similar to challenges faced with poliovirus, influenza, and HIV.