Differential replicative fitness of the four dengue virus serotypes circulating in Colombia in human liver Huh7 cells

Dengue has been a significant public health problem in Colombia since the simultaneouscirculation of the four dengue virus serotypes. The replicative fitness of dengue is a bio-logical feature important for virus evolution and contributes to elucidating the behavior ofvirus populations and viral pathogenesis. However, it has not yet been studied in Colom-bian isolates. This study aimed to compare the replicative fitness of the four dengue virusserotypes and understand the association between the serotypes, their in vitro infectionability, and their replication in target cells. We used three isolates of each DENV serotype toinfect Huh-7 cells at an MOI of 0.5. The percentage of infected cells was evaluated by flowcytometry, cell viability was evaluated by MTT assay, and the pathogenicity index was cal-culated as a ratio of both parameters. The replicative fitness was measured by the numberof viral genome copies produced using quantitative PCR and the production of infectiousviral progeny was measured by plaque assay. We showed that Huh-7 cells were susceptibleto infection with all the different strain isolates. Nevertheless, the biological characteristics,such as infectious ability and cell viability, were strain-dependent. We also found differentdegrees of pathogenicity between strains of the four serotypes, representative of the hetero-geneity displayed in the circulating population. When we analyzed the replicative fitnessusing the mean values obtained from RT-qPCR and plaque assay for the different strains,we found serotype-dependent behavior. The highest mean values of replicative fitness wereobtained for DENV-1 (log 4.9 PFU/ml) and DENV-4 (log 5.28 PFU/ml), followed by DENV-2(log 3.9 PFU/ml) and DENV-3 (log 4.31 PFU/ml). The internal heterogeneity of the replicativefitness within each serotype could explain the simultaneous circulation of the four DENVserotypes in Colombia

• Autores: Gutiérrez Barbosa, Hector Hernando; Castañeda, Nadia Yadira; Castellanos, Jaime
• Fecha de publicación: 2019
• Institución: Universidad El Bosque
• Repositorio: Repositorio U. El Bosque
• Idioma: eng
• OAI Identifier: oai:repositorio.unbosque.edu.co:20.500.12495/1938
• Acceso en línea: http://hdl.handle.net/20.500.12495/1938; https://doi.org/10.1016/j.bjid.2019.11.003
• Palabra clave: Virus del dengue; Infecciones por flavivirus; Virus del dengue -- Epidemiología; Dengue strains; Dengue serotypes; Replicative fitness; Dengue virus
• License: Attribution-NonCommercial-NoDerivatives 4.0 International