Browsing by Author "Ha HJ"

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    Genomic analysis of the 2017 Aotearoa New Zealand outbreak of Mycoplasma bovis and its position within the global population structure
    (Frontiers Media S.A., 2025-07-23) Binney BM; Gias E; Foxwell J; Little A; Biggs PJ; French N; Lambert CL; Ha HJ; Carter GP; Gyuranecz M; Pardon B; De Vliegher S; Boyen F; Bokma J; Krömker V; Wente N; Mahony TJ; Gibson JS; Barnes TS; Wawegama N; Legione AR; Heller M; Schnee C; Pelkonen S; Autio T; Higuchi H; Gondaira S; McCulley M; Cloeckaert A
    In 2017 an outbreak of Mycoplasma bovis (M. bovis), an infectious agent of cattle, was identified in Aotearoa New Zealand. This study characterizes the genomic population structure of the outbreak in New Zealand and compares it with the known global population structure using multilocus sequence typing (MLST) and genomic analysis. The New Zealand outbreak strain was MLST genotyped as ST21. A comprehensive collection of 840 genomes from the New Zealand outbreak showed a pattern of clonal expansion when characterized by MLST, core genome MLST (cgMLST) and whole genome MLST (wgMLST). A lineage of genomes was found with no in silico identifiable pta2 locus, a housekeeping gene used in the MLST scheme. We compared a sample set of 40 New Zealand genomes to 47 genomes from other countries. This group had 79 ST21 genomes and eight genomes that were single nucleotide polymorphism (SNP) variants within the MLST loci of ST21. Two of the 47 international genomes showed signs of extensive unique recombination. Unique alleles in six genes were identified as present only in the New Zealand genomes. These novel variants were in the genes; haeIIIM encoding for cytosine-specific methyltransferase, cysC encoding for cysteinyl tRNA synthetase, era encoding for GTPase Era, metK encoding for S-adenosylmethionine synthase, parE encoding for DNA topoisomerase, and hisS encoding for histidine-tRNA ligase. This finding could be due to a population bottleneck, genetic drift, or positive selection. The same sample set of 40 New Zealand genomes were compared using MLST to 404 genomes from 15 other countries and 11 genomes without a known country. A FastBAPS analysis of 455 genomes showed a global population structure with 11 clusters. Some countries, such as Canada, Denmark and Australia contained both internally closely related genomes and some genomes that were more closely related to genomes found in other countries. Our results support the need for Whole Genome Sequencing (WGS) as well as MLST genotyping in M. bovis outbreaks. They also support the importance of understanding the national and international movement patterns of cattle and their genetic material, as possible routes of transmission, when managing the spread of M. bovis.
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    Uncoupling Molecular Testing for SARS-CoV-2 From International Supply Chains
    (Frontiers Media S.A., 2022-01-24) Stanton J-AL; O'Brien R; Hall RJ; Chernyavtseva A; Ha HJ; Jelley L; Mace PD; Klenov A; Treece JM; Fraser JD; Clow F; Clarke L; Su Y; Kurup HM; Filichev VV; Rolleston W; Law L; Rendle PM; Harris LD; Wood JM; Scully TW; Ussher JE; Grant J; Hore TA; Moser TV; Harfoot R; Lawley B; Quiñones-Mateu ME; Collins P; Blaikie R; Sørensen JL
    The rapid global rise of COVID-19 from late 2019 caught major manufacturers of RT-qPCR reagents by surprise and threw into sharp focus the heavy reliance of molecular diagnostic providers on a handful of reagent suppliers. In addition, lockdown and transport bans, necessarily imposed to contain disease spread, put pressure on global supply lines with freight volumes severely restricted. These issues were acutely felt in New Zealand, an island nation located at the end of most supply lines. This led New Zealand scientists to pose the hypothetical question: in a doomsday scenario where access to COVID-19 RT-qPCR reagents became unavailable, would New Zealand possess the expertise and infrastructure to make its own reagents onshore? In this work we describe a review of New Zealand's COVID-19 test requirements, bring together local experts and resources to make all reagents for the RT-qPCR process, and create a COVID-19 diagnostic assay referred to as HomeBrew (HB) RT-qPCR from onshore synthesized components. This one-step RT-qPCR assay was evaluated using clinical samples and shown to be comparable to a commercial COVID-19 assay. Through this work we show New Zealand has both the expertise and, with sufficient lead time and forward planning, infrastructure capacity to meet reagent supply challenges if they were ever to emerge.