The complete genomic sequence of one human isolate of West Nile virus (WNV) and the partial genomic sequences of 14 other strains from India isolated in the period 1955-1982 from different hosts and geographical areas were determined. Phylogenetic analyses based on complete and partial genomic sequences (921 nt of the C-prM-E region) revealed that WNV could be classified into five distinct groups that differed from each other by 20-25 % at the complete genome level and by 20-26 % using partial sequences. Of the Indian isolates, 13 formed a distinct genetic lineage, lineage 5, whereas two isolates, one from a human patient (1967) and another from a bat (1968), were related closely to lineage 1 strains. The complete genomic sequence of the Indian isolate, 804994, showed 20-22 % genetic divergence from the previously proposed lineage 1 and 2 strains and 24-25 % divergence from isolates of the newly proposed lineages 3 (Rabensburg isolate 97-103 of 1997) and 4 (Russian isolate LEIV- Krnd88-190 of 1998). Similarly, the partial genomic sequences of the Indian isolates showed 21-26 % divergence from lineage 1 and 2 strains and from the Rabensburg (97-103) and Russian isolates. Crossneutralization using strain-specific polyclonal antibodies against lineage 1 strain Eg-101 and representative Indian strains suggests substantial antigenic variation. This study documents circulation of WNV strains typical to India for 27 years and the introduction of lineage 1 strains during 1967-1968. These results indicate strongly that WNV should be classified into five genetic lineages, with Indian viruses constituting the distinct genetic lineage 5.

An outbreak of viral encephalitis occurred in northern India in 2006. Attempts to identify an etiologic agent in cerebrospinal fluid by using reverse transcription–PCR showed positivity to enterovirus (EV) in 66 (21.6%) of 306 patients. Sequencing and phylogenetic analyses of PCR products from 59 (89.3%) of 66 specimens showed similarity with EV-89 and EV-76 sequences.

No abstract

During investigations into the outbreak of encephalitis in 1996 in the Kerala state in India, an arbovirus was isolated from a Culex tritaeniorhynchus mosquito pool. It was characterized as a Japanese encephalitis and West Nile virus cross-reactive arbovirus by complement fixation test. A plaque reduction-neutralization test was performed using hyperimmune sera raised against the plaque-purified arbovirus isolate. The sera did not show reactivity with Japanese encephalitis virus and were weakly reactive with West Nile virus. Complete open reading frame sequence analysis characterized the arbovirus as Bagaza virus (BAGV), with 94.80 % nucleotide identity with African BAGV strain DakAr B209. Sera collected from the encephalitic patients during the acute phase of illness showed 15 % (8/53) positivity for anti-BAGV neutralizing antibodies. This is the first report of the isolation of BAGV from India. The presence of anti-BAGV neutralizing antibodies suggests that the human population has been exposed to BAGV.An outbreak of Japanese encephalitis (JE) was reported from the Allapuzza, Thiruvanthapuram and Kottayam districts of Kerala state, India, during 1996. Only 33 % (50/ 150) of the sera collected from hospitalized cases were confirmed as JE by immunoglobulin M (IgM) ELISA. Other clinical specimens were not available for further investigations. Entomological investigations during the outbreak were carried out and 184 mosquito pools collected from the affected area were processed for isolation in 2-day-old Swiss mice by the intra-cranial route (Rodrigues et al., 1980;George et al., 1984). One pool from Culex tritaeniorhynchus showed sickness in inoculated mice. Brains from sick mice were harvested and suspended in 10 % bovalbumin phosphate saline. The suspensions were stored at 270 u C and designated as the arbovirus isolate (96363). The isolate showed cross-reactivity with anti-JE virus (JEV) and anti-West Nile virus (WNV) immune sera in a complement fixation (CF) test (Pavri & Ghosh, 1969; Rodrigues et al., 1980;Damle et al., 1998).The isolate did not react with immune sera raised against other circulating arboviruses, including Chandipura (Rhabdoviridae), Sindbis (Togaviridae), Chikungunya (Togaviridae), Kyasanur forest disease (Flaviviridae), Batai (Bunyaviridae) and Dengue (Flaviviridae) viruses (Paul et al., 1970; Rodrigues et al., 1980;George et al., 1984).In this study, we present the genetic characterization of the arbovirus isolate and serological analysis of available sera collected from encephalitis patients during 1996. The Institutional Animal Ethical Committee approved this work and ethical guidelines were strictly followed according to their recommendations. The arbovirus isolate was plaque-purified to rule out the possibility of isolation of both JEV and WNV from the mosquito pool. The mouse brain stock of the arbovirus isolate was passaged twice in porcine stable kidney (PS) cells to amplify the virus. A single plaque was selected from the first PS cell passage and then subjected to two sequential ...

Forty-one Tnpho A mutants of Vibrio cholerae O1 classical strain CD81 were analyzed for their ability to interact with chitin particles, Tigriopus fulvus copepods and the Intestine 407 cell line compared to the parent strain. Thirteen mutants were less adhesive than CD81; in particular, T21, T33 and T87 were less adhesive towards all substrates and insensitive to inhibition by N-acetyl glucosamine (GlcNAc). By SDS-PAGE analysis of sarkosyl-insoluble membrane proteins (siMPs) isolated from mutants and parent, it was found that a 53 kDa siMP is missing in T21, T33 and T87 mutants. It is hypothesized that this protein might have the function to mediate adherence to GlcNAc-containing substrates both in the aquatic environment and in human intestine.