Genetic analysis of Dengue 3 virus subtype III 5' and 3' non-coding regions.
The emergence of dengue hemorrhagic fever in Sri Lanka in 1989 correlated with the appearance of a genetic variant of Dengue 3 virus (DENV-3) subtype III (group B), closely related to the endemic group A variant. We studied the 5' and 3' non-coding regions (NCRs) of 15 DENV-3 subtype III isolates from Sri Lanka, Nicaragua and Martinique and found variability in the 3' NCRs. This included an 11-nucleotide insertion common to all isolates examined and two nucleotide differences that segregated viruses geographically into an American and a Sri Lankan group. Comparisons also identified three nucleotide differences shared by all group A Sri Lankan DENV-3 III isolates linked to mild disease epidemics but not group B Sri Lankan and group B-associated American isolates linked to severe disease epidemics. Clustering of the Latin American/Caribbean isolates with Sri Lankan group B DENV-3 in phylogenetic analyses supports the proposed common East African origin for all these strains and confirms the use of the 3' NCR for molecular epidemiologic studies of DENV-3. The differences in the 3' NCRs reported here, as well as potential alterations in the structural and non-structural coding genes, may contribute to the increased pathogenicity of group B DENV-3.
Silva
Ricardo L A
RL
Department of Infectious Diseases, St. Jude Children's Research Hospital, 332 N. Lauderdale, Memphis, TN 38105, USA. rlsilva@inca.gov.br
de Silva
Aravinda M
AM
Harris
Eva
E
MacDonald
Gene H
GH
D020413:3' Untranslated Regions / Q000235:genetics*; D020121:5' Untranslated Regions / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D009033:Culicidae; D003716:Dengue Virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D006801:Humans; D008395:Martinique / Q000453:epidemiology; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D009527:Nicaragua / Q000453:epidemiology; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D019595:Severe Dengue / Q000453:epidemiology / Q000821:virology; D013188:Sri Lanka / Q000453:epidemiology
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions