Genetic divergence of Chikungunya viruses in India (1963-2006) with special reference to the 2005-2006 explosive epidemic
Autor(es): Arankalle Vidya A, Shrivastava Shubham, Cherian Sarah, Gunjikar Rashmi S, Walimbe Atul M, Jadhav Santosh M, Sudeep A B, Mishra Akhilesh C
Resumo: Re-emergence of Chikungunya (CHIK), caused by CHIK virus, was recorded in India during 2005-2006 after a gap of 32 years, causing 1.3 million cases in 13 states. Several isl-s of the Indian Ocean reported similar outbreaks in the same period. These outbreaks were attributed to the African genotype of CHIK virus. To examine relatedness of the Indian isolates (IND-06) with Reunion Isl- isolates (RU), full-genome sequences of five CHIK virus isolates representative of different Indian states were determined. In addition, an isolate obtained from mosquitoes in the year 2000 (Yawat-2000), identified as being of the African genotype, - two older strains isolated in 1963 - 1973 (of the Asian genotype), were sequenced. The IND-06 isolates shared 99.9 % nucleotide identity with RU isolates, confirming involvement of the same strain in these outbreaks. The IND-06 isolates shared 98.2 % identity with the Yawat-2000 isolate. Of two crucial substitutions reported for RU isolates in the E1 region, M269V was noted in the Yawat-2000 - IND-06 isolates, whereas D284E was seen only in the IND-06 isolates. The A226V shift observed with the progression of the epidemic in Reunion Isl-, probably associated with adaptation to the mosquito vector, was absent in all of the Indian isolates. Three unique substitutions were noted in the IND-06 isolates: two (T128K - T376M) in the Nsp1 region - one (P23S) in the capsid protein. The two Asian strains showed 99.4 % nucleotide identity to each other, indicating relative stability of the virus. No evidence of recombination of the Asian - African genotypes, or of positive selection was observed. The results may help in underst-ing the association, if any, of the unique mutations with the explosive nature of the CHIK outbreak.
Imprenta: The Journal of General Virology, v. 88, Pt 7, p. 1967-1976, 2007
Identificador do objeto digital: 10.1099/vir.0.82714-0
Descritores: Chikungunya virus - DNA ; Chikungunya virus - Genome ; Chikungunya virus - Molecular structure ; Chikungunya virus - Pathogenesis ; Chikungunya virus - Viral infections ; Chikungunya Virus - Virus ; Chikungunya virus - Epidemic ; Chikungunya virus - Epidemiology ; Chikungunya virus - Public health
Data de publicação: 2007
