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Fenton, H.

Publications and source records attributed to Fenton, H..

6 recordsLinked to original sources

Metatranscriptomic Identification of Co- and Incidental Infections in Marine Turtles Reveals Complex Disease Aetiologies

Traditional veterinary pathology investigations on wild animals generally conclude a primary cause of death based on a combination of observed clinical signs, gross and microscopic lesions, microbial culture and PCR. However, these methods may fail to capture the broader microbial community of the host. We employed metatranscriptomic sequencing to characterise the potential pathobiome of necropsied marine turtles, comparing these findings with corresponding veterinary pathology reports. Tissue samples were collected from 76 individuals spanning three species of marine turtles -- the green turtle (Chelonia mydas), the hawksbill turtle (Eretmochelys imbricata), and the loggerhead turtle (Caretta caretta) -- across the coastline of New South Wales, Australia. Reported causes of mortality ranged from infectious disease to trauma. We identified a diverse range of parasites within the genera Neospirochis, Hapalotrema, Paraorgymatobothrium, Eimeria and Callitetrarhynchus, and bacteria including the genera Aeromonas, Clostridium, and Vibrio. Novel viruses of the families Astroviridae, Caliciviridae, Hepaciviridae, Hepeviridae, Nyamivirdae, Orthomyxoviridae, Picobirnaviridae and Rhabdoviridae were also identified. In cases where infectious disease was noted in the pathology report, we frequently observed high pathogen read counts consistent with the listed primary diagnoses. However, we also detected a range of incidental infections involving eukaryotic parasites, bacteria, and viruses. The diversity of infectious agents detected in marine turtles suggests that the observed disease outcomes are unlikely to be driven by a single causative agent, but rather by complex interactions between host health, the pathobiome, and environmental stressors. We discuss the potential implications for turtle health and conservation.

molecular biology↗

Metagenomic identification of novel Hepaciviridae in Australian birds reveals pegivirus recombination

The Hepaciviridae family of RNA viruses have a wide range of hosts including arthropods, fish, birds and mammals. Birds are well documented reservoirs of these viruses, owing to their physiological and ecological characteristics that facilitates rapid transmission through populations. To expand our understanding of the avian virome, with a particular focus on the identification of novel hepaciviruses, we performed metatranscriptomic sequencing on tissues taken from Australian endemic birds such as emus, pelicans as well as migratory birds (shearwater and albatross sp., egrets, herons and cuckoos) found deceased in New South Wales, Australia between 2021 and 2025. From these data we identified two novel pegiviruses -- shearwater and Australian pelican pegivirus (denoted SWPgV and APPgV) -- that provided phylogenetic evidence of a putative recombination event, reflected in incongruent tree topologies. SWPgV and APPgV form a sister clade with previously described avian-associated pegiviruses in NS3 phylogenetic trees, yet fell as a unique basal group in phylogenies based on NS5B. The lack of a clear parental lineage in NS5B domains suggests that additional divergent avian-associated pegiviruses have yet to be identified. In addition, we discovered two novel orthohepaciviruses herein named short-tailed shearwater and emu orthohepacivirus (STSHpV and EHpV) that are related to other avian-associated orthohepaciviruses, indicative of a long avian association, as well as a confirmed case of pegivirus and orthohepacivirus co-infection. Combined, these avian hepacivirus findings demonstrate the importance of tissue-based viral discovery studies in uncovering novel virus species and understanding their complex evolutionary histories.

microbiology↗

Detection and genomic characterisation of a novel hantavirus in Australian dolphins

We report the detection of a novel hantavirus in the lung tissue of two diseased Australian dolphins with histopathological changes. Phylogenetic analysis placed this virus within the genus Mobatvirus. This highlights the ability of hantaviruses to infect non-terrestrial mammals and the potential role of marine mammals as one health sentinels.

microbiology↗

Diverse Viral Pathogens in Australian Canines: Limited Geographic Structure and the First Detection of an RNA Virus in Dingoes

Viruses impose a substantial disease burden on dogs and the close relationship between dogs and humans may facilitate zoonotic disease emergence. Australias geographic isolation, strict biosecurity measures and native dingo populations present a unique model for understanding the spread and evolution of canine viruses. However, aside from a few well-characterised pathogens, genomic data are scarce for many common dog viruses, limiting our understanding of their evolution and disease ecology. Using a metatranscriptomic approach we identified the viruses in dogs and dingoes from various geographical locations across mainland Australia and sample types, revealing 86 vertebrate-associated viruses belonging to 16 distinct species, including a new vesivirus-like species. Many of the viruses identified here have not previously been sequenced in Australia. We identified important dog pathogens associated with canine infectious respiratory disease syndrome--such as canine pneumovirus, canine herpesvirus, and canine respiratory coronavirus--and gastroenteritis, including canine parvovirus, canine coronavirus, and rotavirus A. The sequences of Australian canine viruses often occupied multiple distinct clades phylogenetically and had little geographic structure, suggesting multiple virus introductions and subsequent spread across the country. Notably, we identified the first RNA virus - rotavirus A - in a dingo. This virus was phylogenetically distinct from dog-associated rotavirus A sequences and more closely related to viruses found in humans and bats, indicative of the past cross-species transmission of a reassortant virus into dingoes, and shows dingoes and domestic dogs may have distinct viromes. Our findings expand the knowledge of viral diversity in Australian canines, improving our understanding of viral movement into and within Australia, as well as the potential zoonotic risks associated with dogs and dingoes.

microbiology↗

Diverse fox circovirus (Circovirus canine) variants circulate at high prevalence in grey wolves (Canis lupus)

Canine circoviruses (CanineCV) have a worldwide distribution in dogs and are occasionally detected in wild carnivorans, indicating their ability for cross-species transmission. However, fox circovirus, a lineage of CanineCV, has been identified exclusively in wild canids. We analyzed spleen samples from 159 grey wolves from the Northwest Territories, Canada, to investigate the molecular epidemiology of CanineCV and formulate hypotheses about virus ecology and evolution. Overall, 72 out of 159 (45.3%) animals tested positive. Virus prevalence was similar between males and females, adults and juveniles, and across the investigated years and locations. CanineCV infection was not associated with a poor body condition. While the percentage of co-infections with canine parvoviruses, investigated in a previous study, was high (63/72, 87.5%), the rate of parvovirus infection in CanineCV-negative animals was significantly lower (42/87, 48.3%, {chi}2 = 27.03, p < 0.001), and CanineCV infection was associated with a 7.5- and 2.4-fold increase in the risk of acquiring canine parvovirus 2 or canine bufavirus infections, respectively (odds ratios: 3.5-16.9 and 1.3-5.8). Although common risk factors cannot be ruled out, this suggests that CanineCV may facilitate parvoviral super-infections. Sequencing revealed high CanineCV genetic diversity, further exacerbated by recombination. Of the 69 sequenced strains, 87.5% were fox circoviruses, five were related to a fox circovirus-like recombinant strain, and one belonged to a distant lineage. In the phylogenetic analysis, the virus sequences were distributed according to sampling locations, with some viruses being geographically restricted. Different clades of viruses were identified in the same areas and over multiple years (2007-2019), indicating the co-existence of multiple endemic lineages in the investigated area. Phylogenetic analysis of all available complete fox circovirus genomes (32 from foxes and 15 from wolves from North America and Europe) demonstrated four lineages, each including sequences from this study. Within each lineage, strains segregated geographically and not by host. This implies that, although multiple lineages co-exist, viruses do not frequently move between locations. Finally, viruses from Europe and North America were mixed, indicating that the origin of the four lineages might predate the segregation of European and American wolf and fox populations. Given the high prevalence and diversity of fox circoviruses in wolves, these animals should be considered reservoir hosts for these viruses. Although we cannot exclude a lower susceptibility of dogs, the lack of fox circovirus in dogs could be due to environmental circumstances that prevented its spread to dogs. Given the high diversity and wild host specificity, we presume a long-lasting association between fox circovirus and canine hosts and hypothesize a higher likelihood of transmission from dogs to wild animals than vice versa. Further studies should investigate other sympatric wild species and additional locations to explore the possible existence of additional maintenance hosts and the reasons behind the marked difference in cross-species transmission dynamics among CanineCV lineages.

microbiology↗

New Records of California Serogroup Virus in Aedes Mosquitoes and First Detection in Simulioidae Flies from Northern Canada and Alaska

An expected consequence of climate warming is an expansion of the geographic distribution of biting insects and associated arthropod-borne diseases (arboviruses). Emerging and reemerging arboviruses that can affect human health are likely to pose significant consequences for Northern communities where access to health resources is limited. In the North American Arctic, little is known about arboviruses. Thus, in 2019, we sampled biting insects in Nunavik (Kuujjuaq), Nunavut (Igloolik, Karrak Lake and Cambridge Bay), Northwest Territories (Igloolik and Yellowknife) and Alaska (Fairbanks). The main objective was to detect the presence of California serogroup viruses (CSGv) - a widespread group of arboviruses across North America and that is known to cause a wide range of symptoms, ranging from mild febrile illness to fatal encephalitis. Biting insects were captured twice daily for a 7-day period in mid-summer, using a standardized protocol consisting of 100 figure-eight movements of a sweep net. Captured specimens were separated by genus (mosquitoes) or by superfamily (other insects), and then grouped into pools of 75 by geographical locations. In total, 5079 Aedes mosquitoes and 1014 Simulioidae flies were caught. We report the detection of CSGv RNA in mosquitoes captured in Nunavut (Karrak Lake) and Nunavik (Kuujjuaq). We also report, for the first time in North America, the presence of CSGv RNA in Simulioidae flies. These results highlight the potential of biting insects for tracking any future emergence of arboviruses in the North, thereby providing key information for public health in Northern communities.

microbiology↗