Molecular characterization of chikungunya virus from Andhra Pradesh, India & phylogenetic relationship with Central African isolates.

BACKGROUND & OBJECTIVE Chikungunya virus has caused numerous large outbreaks in India. Suspected blood samples from the epidemic were collected and characterized for the identification of the responsible causative from Rayalaseema region of Andhra Pradesh. METHODS RT-PCR was used for screening of suspected blood samples. Primers were designed to amplify partial E1 gene and the amplified fragment was cloned and sequenced. The sequence was analyzed and compared with other geographical isolates to find the phylogenetic relationship. RESULTS The sequence was submitted to the Gen bank DNA database (accession DQ888620). Comparative nucleotide homology analysis of the AP Ra-CTR isolate with the other isolates revealed 94.7+/-3.6 per cent of homology of CHIKAPRa-CTR with other isolates of Chikungunya virus at nucleotide level and 96.8+/-3.2 per cent of homology at amino acid level. INTERPRETATION & CONCLUSION The current epidemic was caused by the Central African genotype of CHIKV, grouped in Central Africa cluster in phylogenetic trees generated based on nucleotide and amino acid sequences.