Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

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    Host phylogeny shapes viral transmission networks in an island ecosystem
    (Springer Nature Limited, 2023-11) French RK; Anderson SH; Cain KE; Greene TC; Minor M; Miskelly CM; Montoya JM; Wille M; Muller CG; Taylor MW; Digby A; Kākāpō Recovery Team; Holmes EC
    Virus transmission between host species underpins disease emergence. Both host phylogenetic relatedness and aspects of their ecology, such as species interactions and predator-prey relationships, may govern rates and patterns of cross-species virus transmission and hence zoonotic risk. To address the impact of host phylogeny and ecology on virus diversity and evolution, we characterized the virome structure of a relatively isolated island ecological community in Fiordland, New Zealand, that are linked through a food web. We show that phylogenetic barriers that inhibited cross-species virus transmission occurred at the level of host phyla (between the Chordata, Arthropoda and Streptophyta) as well as at lower taxonomic levels. By contrast, host ecology, manifest as predator-prey interactions and diet, had a smaller influence on virome composition, especially at higher taxonomic levels. The virus-host community comprised a 'small world' network, in which hosts with a high diversity of viruses were more likely to acquire new viruses, and generalist viruses that infect multiple hosts were more likely to infect additional species compared to host specialist viruses. Such a highly connected ecological community increases the likelihood of cross-species virus transmission, particularly among closely related species, and suggests that host generalist viruses present the greatest risk of disease emergence.
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    Total infectome investigation of diphtheritic stomatitis in yellow-eyed penguins (Megadyptes antipodes) reveals a novel and abundant megrivirus.
    (Elsevier B.V., 2023-11-01) Wierenga JR; Grimwood RM; Taylor HS; Hunter S; Argilla LS; Webster T; Lim L; French R; Schultz H; Jorge F; Bostina M; Burga L; Swindells-Wallace P; Holmes EC; McInnes K; Morgan KJ; Geoghegan JL
    First identified in 2002, diphtheritic stomatitis (DS) is a devastating disease affecting yellow-eyed penguins (Megadyptes antipodes, or hoiho in te reo Māori). The disease is associated with oral lesions in chicks and has caused significant morbidity and mortality. DS is widespread among yellow-eyed penguin chicks on mainland New Zealand yet appears to be absent from the subantarctic population. Corynebacterium spp. have previously been suspected as causative agents yet, due to inconsistent cultures and inconclusive pathogenicity, their role in DS is unclear. Herein, we used a metatranscriptomic approach to identify potential causative agents of DS by revealing the presence and abundance of all viruses, bacteria, fungi and protozoa - together, the infectome. Oral and cloacal swab samples were collected from presymptomatic, symptomatic and recovered chicks along with a control group of healthy adults. Two novel viruses from the Picornaviridae were identified, one of which - yellow-eyed penguin megrivirus - was highly abundant in chicks irrespective of health status but not detected in healthy adults. Tissue from biopsied oral lesions also tested positive for the novel megrivirus upon PCR. We found no overall clustering among bacteria, protozoa and fungi communities at the genus level across samples, although Paraclostridium bifermentans was significantly more abundant in oral microbiota of symptomatic chicks compared to other groups. The detection of a novel and highly abundant megrivirus has sparked a new line of inquiry to investigate its potential association with DS.
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    A novel gyrovirus is abundant in yellow-eyed penguin (Megadyptes antipodes) chicks with a fatal respiratory disease.
    (2023-02) Wierenga JR; Morgan KJ; Hunter S; Taylor HS; Argilla LS; Webster T; Dubrulle J; Jorge F; Bostina M; Burga L; Holmes EC; McInnes K; Geoghegan JL
    Yellow-eyed penguins (Megadyptes antipodes), or hoiho in te reo Māori, are predicted to become extinct on mainland Aotearoa New Zealand in the next few decades, with infectious disease a significant contributor to their decline. A recent disease phenomenon termed respiratory distress syndrome (RDS) causing lung pathology has been identified in very young chicks. To date, no causative pathogens for RDS have been identified. In 2020 and 2021, the number of chick deaths from suspected RDS increased four- and five-fold, respectively, causing mass mortality with an estimated mortality rate of >90%. We aimed to identify possible pathogens responsible for RDS disease impacting these critically endangered yellow-eyed penguins. Total RNA was extracted from tissue samples collected during post-mortem of 43 dead chicks and subject to metatranscriptomic sequencing and histological examination. From these data we identified a novel and highly abundant gyrovirus (Anelloviridae) in 80% of tissue samples. This virus was most closely related to Gyrovirus 8 discovered in a diseased seabird, while other members of the genus Gyrovirus include Chicken anaemia virus, which causes severe disease in juvenile chickens. No other exogenous viral transcripts were identified in these tissues. Due to the high relative abundance of viral reads and its high prevalence in diseased animals, it is likely that this novel gyrovirus is associated with RDS in yellow-eyed penguin chicks.