Search bioRxiv⌕ Search

Biology subjects

Poulson, R. L.

Publications and source records attributed to Poulson, R. L..

3 recordsLinked to original sources

Rapid phylogenomic analysis for viral surveillance and metagenomic profiling with Omni2Tree

Phylogenomic surveillance is limited not by sequencing throughput, but by the difficulty of converting heterogeneous raw data into reliable evolutionary inference, particularly for low-titer and contaminated viral field samples. Here we present Omni2Tree, an assembly-free framework that reconstructs viral phylogenies directly from raw sequencing reads and generates easily shareable interactive reports and genome-wide entropy profiles to identify diversification. In H5N1 benchmark analyses, Omni2Tree maintained accurate placement and topological stability even under low coverage, unlike assembly or reference based methods. Omni2Tree generated an annotated phylogeny for 64-sample H5N1 field surveillance dataset from the eastern USA in under 3 hours. Omni2Tree recovered known phylogenetic structure and key variability insights across 1,328 hepatitis C virus and 707 human cytomegalovirus datasets, and resolved co-infecting respiratory viruses in clinical metagenomic samples. By enabling direct analysis from raw reads, Omni2Tree supports faster, more portable, and more decentralized phylogenomic surveillance across outbreak, clinical, and resource-limited settings.

bioinformatics↗

Putative novel avian paramyxoviruses identified from wild bird surveillance (United States, 2016?2018) and retrospective analysis of APMV-2s and APMV-6s in GenBank

Avian paramyxoviruses (APMVs) (subfamily Avulavirinae) have been isolated from over 200 species of wild and domestic birds from around the world. The International Committee on Taxonomy of Viruses (ICTV) currently defines 22 different APMV species, with Avian orthoavulavirus 1 (whose viruses are designated as APMV-1) being the most frequently studied due to its economic burden to the poultry industry. Less is known about other APMV species, including limited knowledge on the genetic diversity in wild birds and there is a paucity of public whole genome sequences for APMV-2 to -22. The goal of this study was to use MinION sequencing to genetically characterize APMVs isolated from wild bird swab samples collected during 2016-2018 in the United States. Multiplexed MinION libraries were prepared using a random strand-switching approach using 37 egg-cultured, influenza-negative, hemagglutination-positive samples. Thirty-five APMV isolates that had complete polymerase coding sequences were speciated using ICTVs current Paramyxoviridae phylogenetic methodology. Viruses from APMV-1, -4, -6, -8 were classified, one putative novel species (Avian orthoavulavirus 23) was identified from viruses isolated in this study, two putative new APMV species (Avian metaavulavirus 24 and 27) were identified from viruses isolated in this study and from retrospective GenBank sequences, and two putative new APMV species (Avian metaavulavirus 25 and 26) were identified solely from retrospective GenBank sequences. Furthermore, co-infections of APMVs were identified in a subset of the samples. The potential limitations of the branch length being the only speciation criterion and the potential benefit of a group pairwise distance analysis are discussed. ImportanceMost species of APMVs are understudied and/or underreported and many species were incidentally identified from asymptomatic wild birds; however, the disease significance of APMVs in wild birds is not fully determined. The rapid rise in high-throughput sequencing coupled with avian influenza surveillance programs have identified 12 different APMV species in the last decade and have challenged the resolution of classical serological methods to identify new viral species. Currently, ICTVs only criterion for Paramyxoviridae species classification is the requirement of a branch length >0.03 using a phylogenetic tree constructed from polymerase (L) amino acid sequences. The results from this study identify one new APMV species, propose four additional new APMV species, and highlight that the criterion may have insufficient resolution for APMV species demarcation and that refinement or expansion of this criterion may need to be established for Paramyxoviridae speciation.

microbiology↗

Randomly primed, strand-switching MinION-based sequencing for the detection and characterization of cultured RNA viruses

RNA viruses rapidly mutate, which can result in increased virulence, increased escape from vaccine protection, and false negative detection results. Targeted detection methods have a limited ability to detect unknown viruses and often provide insufficient data to detect coinfections or identify antigenic variants. Random, deep sequencing is a method that can more fully detect and characterize RNA viruses and is often coupled with molecular techniques or culture methods for viral enrichment. Viral culture coupled with third-generation sequencing were tested for the ability to detect and characterize RNA viruses. Cultures of bovine viral diarrhea virus, canine distemper virus, epizootic hemorrhagic disease virus, infectious bronchitis virus, two influenza A viruses, and porcine respiratory and reproductive syndrome virus were sequenced on the MinION platform using a random, reverse primer in a strand-switching reaction, coupled with PCR-based barcoding. Reads were taxonomically classified and used for reference-based sequence building using a stock personal computer. This method accurately detected and identified complete coding sequence genomes with a minimum of 20x coverage depth for all seven viruses, including a sample containing two viruses. Each lineage-typing region had at least 26x coverage depth for all viruses. Furthermore, analyzing the canine distemper virus sample through a pipeline devoid of canine distemper virus reference sequences modeled the ability of this protocol to detect unknown viruses. These results show the ability of this technique to detect and characterize dsRNA, negative- and positive-sense ssRNA, nonsegmented, and segmented RNA viruses.

pathology↗