Biology subjects

Mills, M. G.

Publications and source records attributed to Mills, M. G..

3 recordsLinked to original sources

bioRxiv2025

Clinical performance evaluation of a tiling amplicon panel for whole genome sequencing of respiratory syncytial virus

Accurate genomic characterization of respiratory syncytial virus (RSV) is crucial for studies of epidemiology and viral evolution, and monitoring potential escape from newly authorized vaccines and antivirals. We adapted a viral whole genome tiling amplicon panel (UW-ARTIC) and developed a custom bioinformatic pipeline for high-throughput, cost-effective sequencing of RSV-A and RSV-B. We established genome acceptability criteria and determined the performance characteristics of the panel including assay sensitivity, specificity, breadth of genome recovery, accuracy, and precision using contrived and remnant clinical specimens. High-quality genomes (>95% genome completeness; >500X and >1000X average depth for whole genome and fusion gene respectively) were recovered from samples with Ct [≤] 30 ([~]594 and 2,004 copies per reaction for RSV-A and RSV-B respectively). Minor variants were accurately identified in sample mixtures of 5:95 and higher. The assay showed high accuracy when compared against Sanger, shotgun metagenomic, and hybridization capture-based sequencing; and high repeatability and reproducibility. The UW-ARTIC RSV panel has utility in genomic surveillance, clinical and research applications. It has been used to generate FDA-reportable data for clinical trials of RSV antiviral products, with robust performance characteristics in samples from around the globe from as recently as the 2023/24 season. Continued genomic surveillance and future updates to primer sets will be essential for continued recovery of genomes as RSV continues to evolve.

genomics↗

bioRxiv2024

Variant mutation in SARS-CoV-2 nucleocapsid enhances viral infection via altered genomic encapsidation

The evolution of SARS-CoV-2 variants and their respective phenotypes represents an important set of tools to understand basic coronavirus biology as well as the public health implications of individual mutations in variants of concern. While mutations outside of Spike are not well studied, the entire viral genome is undergoing evolutionary selection, particularly the central disordered linker region of the nucleocapsid (N) protein. Here, we identify a mutation (G215C), characteristic of the Delta variant, that introduces a novel cysteine into this linker domain, which results in the formation of a disulfide bond and a stable N-N dimer. Using reverse genetics, we determined that this cysteine residue is necessary and sufficient for stable dimer formation in a WA1 SARS-CoV-2 background, where it results in significantly increased viral growth both in vitro and in vivo. Finally, we demonstrate that the N:G215C virus packages more nucleocapsid per virion and that individual virions are larger, with elongated morphologies.

microbiology↗

bioRxiv2023

Surveillance of Vermont wildlife in 2021-2022 reveals no detected SARS-CoV-2 viral RNA

Previous studies have documented natural infections of SARS-CoV-2 in various domestic and wild animals. More recently, studies have been published noting the susceptibility of members of the Cervidae family, and infections in both wild and captive cervid populations. In this study, we investigated the presence of SARS-CoV-2 in mammalian wildlife within the state of Vermont. 739 nasal or throat samples were collected from wildlife throughout the state during the 2021 and 2022 harvest season. Data was collected from red and gray foxes (Vulpes vulples and Urocyon cineroargentus, respectively), fishers (Martes pennati), river otters (Lutra canadensis), coyotes (Canis lantrans), bobcats (Lynx rufus rufus), black bears (Ursus americanus), and white-tailed deer (Odocoileus virginianus). Samples were tested for the presence of SARS-CoV-2 via quantitative RT-qPCR using the CDC N1/N2 primer set and/or the WHO-E gene primer set. Our results indicate that no sampled wildlife were positive for SARS-CoV-2. This finding is surprising, given that most published North America studies have found SARS-CoV-2 within their deer populations. The absence of SARS-CoV-2 RNA in populations sampled here may provide insights in to the various environmental and anthropogenic factors that reduce spillover and spread in North Americans wildlife populations.

microbiology↗