GENOTYPING OF DENGUE VIRUS 2 USING RESTRICTION SITE-SPECIFIC (RSS)-PCR

Dengue fever is considered the most important and widespread reemerging infectious disease in developing countries. Dengue virus belongs to the family Flaviviridae, a group of positive sense RNA viruses of 11 kb that are divided into four antigenically distinct serotypes (DENV-1 - DENV-4). Nowadays prevention is accomplished by using epidemiologic surveillance and vector control. Strain typing is a powerful tool for determining the geographic distribution of strains and understanding the epidemiology of infectious diseases. Strain typing can provide information on the relationship between disease manifestations and severity of disease. Harris et al. (Virology 253: 86-95, 1990), developed the RSS-PCR in order to genotype samples of Dengue virus, a rapid molecular strain-typing method that can be applied to analyze a large number of strains. The subtyping may identify viral factors that contribute to disease severity. This study was developed in order to genotype samples circulating in Minas Gerais state. Among the 34 clinical samples tested, 3 were DENV-1, 14 were DENV-2 and 17 were DENV-3. The samples were isolated using C6/36 cells. After RNA extraction using the silica method, RSS-PCR was executed. Different samples were used (1992-2005), including cases of DF (dengue fever) and DHF (dengue hemorrhagic fever). The results suggest genetic variability among the samples. The patterns seem to be related to the period of isolation, whether recent or from retrospective samples, as differences in patterns linked to severity of disease were not seen. The older sample (1992) seemed to have the same pattern as that ascribed by Harris et al, (1990) to the genotype “American”. The other samples showed patterns not related to any other previously described genotype. DOI: http://dx.doi.org/10.17525/vrr.v13i1-2.19