The study evaluated antiviral efficacy of antibiotics- Doxycycline and Kanamycinagainst Japanese encephalitis virus (JEV) infection in vivo. Adult Swiss albino mice (4- 6weeks) were used. Mice were distributed in four groups- control group (A), only drug group(B), JEV infected group (C) and JEV + drug treated group (D). Mice were given intravenousinoculation of JEV strain P20778. Doxycycline was given via intra peritoneal (i. p.) route at 50mg/kg dose. Kanamycin was given to mice via subcutaneous (s. c.) route at 20 mg/kg dose. Alldrug dosages were administered at 24 hr, 48 hr and 96 hr post infection (p.i.) twice a day (BID)for upto 14 days. The mice were monitored for 21 days. The viral load was determined byplaque assay. Viral RNA load and cytokine levels were determined. The infected mice died by8 days of infection. Doxycycline treatment at 50 mg/kg dose after 24 hr p.i. lowered diseaseprogression, prolonging the survival of the animals by a week. Antiviral effect was evidentwith reduction of progeny plaque formation. The plaque formation was reduced at 24 hr p.i.compared to virus group. Doxycycline inhibited viral RNA replication. Doxycycline was ableto moderately modulate proinflammatory cytokines. Kanamycin administration was lesseffective. Thus, the studies demonstrated encouraging results in treatment of JEV infectionby Doxycycline. It indicated that Doxycycline delayed the disease progression. Thus, thefindings suggest that Doxycycline could be used as an adjuvant treatment against JE.

Objective: To assess the best suitable condition for virus inactivation, and to study the immunogenic potential and protective efficacy of a circulating West Nile virus (WNV) strain in Assam. Methods: Bulk preparation of circulating WNV: WNIRGC07 (GeneBank ID: HQ246154), was undertaken in a bioreactor using cytodex-1. Virus Inactivation was done in three different conditions; 22 °C, 4 °C and room temperature. The virus preparations were evaluated for antigenicity by ELISA and toxicity by cell proliferation kit. Virus efficacy was done in-vivo on swiss albino mice against standard Indian WNV and Japanese encephalitis virus (JEV) strain. Humoral and cell mediated immune response was evaluated in mice sera by ELISA and neutralization assay. Results: Inactivation at 22 °C was found to be more suitable in terms of less toxicity and high antigenicity. The same was selected to study the immune response and efficacy in mice. It induced neutralizing antibody titre of 1: 625 and high IgG response. In vivo experiment showed 100% protective efficacy against WNV and 20.8% cross protective efficacy against JEV. Further assessment of cellular immunity through immunized mice revealed augmentation of high levels of pro-inflammatory cytokines and moderate levels of anti-cytokines indicating a mixed balance of Th1 and Th2 response. Conclusions: Findings suggest that formalin inactivated Indian WNV strain has a good immunogenic potential. This is the first study on assessment of immunogenic potential of a lineage 5 strain of WNV. Our study reveals that it would be a promising and effective candidate for vaccine studies which warrants further evaluation.

Objective: To explore the antiviral activity of antibiotic compounds, mainly aminoglycosides and tetracyclines against Japanese encephalitis virus (JEV) induced infection in vitro. Methods: Antiviral activity were evaluated against JEV using cytopathic effect inhibition assay, virus yield reduction assay, caspase 3 level, extracellular viral detection by antigen capture ELISA and viral RNA levels. Results: JEV induced cytopathic effect along with reduction of viral progeny plaque formation indicated antiviral potential of the compounds suggesting that antibiotics had broad spectrum activity. Doxycycline and kanamycin administration in dose dependent manner declined viral RNA replication. Conclusions: The present study shows kanamycin and doxycycline can affect virion structure and alter replication causing inhibition of JEV induced pathogenesis in vitro.

Objective: To depict mitochondrial genetic variation for the first time among Anopheles minimus (. An.minimus) (Diptera: Culicidae) species from two malaria endemic states of NE India. Methods: Phylogeographic analysis was carried at 9 out of 12 sites of An.minimus confirmed malaria endemic places. Results: All sequences were Adenine-Thymine rich regions. Transitions were observed in 6 sequences where 5 mutations were synonymous substitutions and in 1 case non synonymous mutation was observed. Three distinct clusters of haplotypes were generated. Haplotype diversity and low nucleotide diversity were studied. Overall negative values obtained from Tajima's D test and Fu'sF