Rapid virulence prediction and identification of Newcastle disease virus genotypes using third-generation sequencing
VIROLOGY JOURNAL
Authors: Butt, Salman L.; Taylor, Tonya L.; Volkening, Jeremy D.; Dimitrov, Kiril M.; Williams-Coplin, Dawn; Lahmers, Kevin K.; Miller, Patti J.; Rana, Asif M.; Suarez, David L.; Afonso, Claudio L.; Stanton, James B.
Abstract
BackgroundNewcastle disease (ND) outbreaks are global challenges to the poultry industry. Effective management requires rapid identification and virulence prediction of the circulating Newcastle disease viruses (NDV), the causative agent of ND. However, these diagnostics are hindered by the genetic diversity and rapid evolution of NDVs.MethodsAn amplicon sequencing (AmpSeq) workflow for virulence and genotype prediction of NDV samples using a third-generation, real-time DNA sequencing platform is described here. 1D MinION sequencing of barcoded NDV amplicons was performed using 33 egg-grown isolates, (15 NDV genotypes), and 15 clinical swab samples collected from field outbreaks. Assembly-based data analysis was performed in a customized, Galaxy-based AmpSeq workflow. MinION-based results were compared to previously published sequences and to sequences obtained using a previously published Illumina MiSeq workflow.ResultsFor all egg-grown isolates, NDV was detected and virulence and genotype were accurately predicted. For clinical samples, NDV was detected in ten of eleven NDV samples. Six of the clinical samples contained two mixed genotypes as determined by MiSeq, of which the MinION method detected both genotypes in four samples. Additionally, testing a dilution series of one NDV isolate resulted in NDV detection in a dilution as low as 10(1) 50% egg infectious dose per milliliter. This was accomplished in as little as 7min of sequencing time, with a 98.37% sequence identity compared to the expected consensus obtained by MiSeq.ConclusionThe depth of sequencing, fast sequencing capabilities, accuracy of the consensus sequences, and the low cost of multiplexing allowed for effective virulence prediction and genotype identification of NDVs currently circulating worldwide. The sensitivity of this protocol was preliminary tested using only one genotype. After more extensive evaluation of the sensitivity and specificity, this protocol will likely be applicable to the detection and characterization of NDV.
Resiquimod inhibits Newcastle disease virus replication by modulating host cytokines: An understanding towards its possible therapeutics
CYTOKINE
Authors: Gupta, Anjali; Deka, Pankaj; Kumar, Sachin
Abstract
Newcastle disease virus (NDV) infects domestic and wild avian species with high mortality and morbidity worldwide. Although this disease is mainly controlled through NDV vaccines, alternative use of antiviral compounds is increasingly under study. Resiquimod (R-848), an imidazoquinoline compound is a potent synthetic agonist of Toll-like receptor 7 (TLR7). Until now reports regarding the adjuvant potential of resiquimod is well established against human viruses but has been less explored against avian viruses. In the present study, we have analysed the anti-NDV effect of resiquimod in chicken embryo fibroblast cells (DF-1) and embryonated chicken eggs. About 70% reduction in NDV replication was observed 48 h and 72 h post-resiquimod treatment in DF-1 cells. Furthermore, differential host genes expression was observed in resiquimod treated DF-1 cells, PBMCs, and tissue sample of chicken embryos at a different time point. Among all the analyzed genes, significant up-regulation of viperin, IFN alpha, IFN gamma, IL-1 beta, TNF alpha, IL18 were observed in its transcriptional level. Furthermore, resiquimod treatment showed NDV reduction in two weeks old chickens. About 61% and 38% reduction in NDV replication was observed 72 h post-infection in lungs and spleen, respectively. The study suggests the modulation of host innate immunity regulatory genes by resiquimod, which eventually modulates the NDV replication. The result of the study could be explored further to establish resiquimod as an alternative antiviral compound against NDV.