title: Characterization of West Nile virus (WNV) isolates from Assam, India: insights into the circulating WNV in northeastern India.
abstract: West Nile virus (WNV) is a mosquito-borne flavivirus that causes subclinical symptoms, febrile illness with possible kidney infarction and encephalitis. Since WNV was first serologically detected in Assam during 2006, it has become recognized as an important etiological agent that causes acute encephalitis syndrome (AES) in addition to endemic Japanese encephalitis virus (JEV). Therefore, isolating and characterizing the currently circulating strain of WNV is important. The virus was isolated from the cerebrospinal fluid (CSF) of two patients that presented with AES. The genotyping of the isolates HQ246154 (WNIRGC07) and JQ037832 (WNIRTC08) based on the partial sequencing of 921 nucleotides (C-prM-E) of the genome placed them within lineage 5 along with other Indian strains isolated prior to 1982, but the present circulating virus formed a distinct subclade. The derived amino acid sequence alignment indicated substitution in A81T and A84P of the capsid region in HQ246154. A cross-neutralization assay suggested substantial antigenic variation between isolates. The pathogenesis in mice that suggested the circulating WNV was neuroinvasive and comparatively more pathogenic than previous strains from India.
authors.affiliation: Entomology and Filariasis Division, Arbovirology Group, Regional Medical Research Centre (ICMR), N.E. Region, Post-Box. 105 Dibrugarh, Assam, India. Electronic address: pritomc@gmail.com.
authors.forename: Pritom
authors.initials: P
authors.lastname: Chowdhury
authors.affiliation: Entomology and Filariasis Division, Arbovirology Group, Regional Medical Research Centre (ICMR), N.E. Region, Post-Box. 105 Dibrugarh, Assam, India. Electronic address: sirajkhanicmr@gmail.com.
authors.forename: Siraj Ahmed
authors.initials: SA
authors.lastname: Khan
authors.affiliation: Entomology and Filariasis Division, Arbovirology Group, Regional Medical Research Centre (ICMR), N.E. Region, Post-Box. 105 Dibrugarh, Assam, India. Electronic address: duttaprafulla@yahoo.com.
authors.forename: Prafulla
authors.initials: P
authors.lastname: Dutta
authors.affiliation: Entomology and Filariasis Division, Arbovirology Group, Regional Medical Research Centre (ICMR), N.E. Region, Post-Box. 105 Dibrugarh, Assam, India. Electronic address: rashmeetopno@gmail.com.
authors.forename: Rashmee
authors.initials: R
authors.lastname: Topno
authors.affiliation: Entomology and Filariasis Division, Arbovirology Group, Regional Medical Research Centre (ICMR), N.E. Region, Post-Box. 105 Dibrugarh, Assam, India. Electronic address: jmahanta@gmail.com.
authors.forename: Jagadish
authors.initials: J
authors.lastname: Mahanta
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000940:Antigenic Variation; D001483:Base Sequence; D002648:Child; D005838:Genotype; D006801:Humans; D007194:India; D008297:Male; D051379:Mice; D008875:Middle Aged; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D010802:Phylogeny; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014774:Virulence; D014901:West Nile Fever / Q000134:cerebrospinal fluid / Q000821:virology*; D014902:West Nile virus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D012367:RNA, Viral
keywords: Cross-neutralization; Genotyping; Pathogenicity; West Nile virus