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1.
J Virol ; 94(18)2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32581107

RESUMO

Wild birds are major natural reservoirs and potential dispersers of a variety of infectious diseases. As such, it is important to determine the diversity of viruses they carry and use this information to help understand the potential risks of spillover to humans, domestic animals, and other wildlife. We investigated the potential viral causes of paresis in long-standing, but undiagnosed, disease syndromes in wild Australian birds. RNA from diseased birds was extracted and pooled based on tissue type, host species, and clinical manifestation for metagenomic sequencing. Using a bulk and unbiased metatranscriptomic approach, combined with clinical investigation and histopathology, we identified a number of novel viruses from the families Astroviridae, Adenoviridae, Picornaviridae, Polyomaviridae, Paramyxoviridae, Parvoviridae, and Circoviridae in common urban wild birds, including Australian magpies, magpie larks, pied currawongs, Australian ravens, and rainbow lorikeets. In each case, the presence of the virus was confirmed by reverse transcription (RT)-PCR. These data revealed a number of candidate viral pathogens that may contribute to coronary, skeletal muscle, vascular, and neuropathology in birds of the Corvidae and Artamidae families and neuropathology in members of the Psittaculidae The existence of such a diverse virome in urban avian species highlights the importance and challenges in elucidating the etiology and ecology of wildlife pathogens in urban environments. This information will be increasingly important for managing disease risks and conducting surveillance for potential viral threats to wildlife, livestock, and human health.IMPORTANCE Wildlife naturally harbor a diverse array of infectious microorganisms and can be a source of novel diseases in domestic animals and human populations. Using unbiased RNA sequencing, we identified highly diverse viruses in native birds from Australian urban environments presenting with paresis. This research included the clinical investigation and description of poorly understood recurring syndromes of unknown etiology: clenched claw syndrome and black and white bird disease. As well as identifying a range of potentially disease-causing viral pathogens, this study describes methods that can effectively and efficiently characterize emergent disease syndromes in free-ranging wildlife and promotes further surveillance for specific pathogens of potential conservation and zoonotic concern.


Assuntos
Animais Selvagens/virologia , Doenças das Aves/epidemiologia , Aves/virologia , Infecções por Vírus de DNA/veterinária , Metagenoma , Infecções por Vírus de RNA/veterinária , Transcriptoma , Adenoviridae/classificação , Adenoviridae/genética , Adenoviridae/isolamento & purificação , Animais , Astroviridae/classificação , Astroviridae/genética , Astroviridae/isolamento & purificação , Austrália/epidemiologia , Doenças das Aves/virologia , Circoviridae/classificação , Circoviridae/genética , Circoviridae/isolamento & purificação , Cidades , Infecções por Vírus de DNA/epidemiologia , Infecções por Vírus de DNA/virologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Paramyxoviridae/classificação , Paramyxoviridae/genética , Paramyxoviridae/isolamento & purificação , Parvoviridae/classificação , Parvoviridae/genética , Parvoviridae/isolamento & purificação , Filogenia , Picornaviridae/classificação , Picornaviridae/genética , Picornaviridae/isolamento & purificação , Polyomaviridae/classificação , Polyomaviridae/genética , Polyomaviridae/isolamento & purificação , Infecções por Vírus de RNA/epidemiologia , Infecções por Vírus de RNA/virologia
2.
PLoS Pathog ; 15(12): e1008216, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31887217

RESUMO

Eukaryotes of the genus Plasmodium cause malaria, a parasitic disease responsible for substantial morbidity and mortality in humans. Yet, the nature and abundance of any viruses carried by these divergent eukaryotic parasites is unknown. We investigated the Plasmodium virome by performing a meta-transcriptomic analysis of blood samples taken from patients suffering from malaria and infected with P. vivax, P. falciparum or P. knowlesi. This resulted in the identification of a narnavirus-like sequence, encoding an RNA polymerase and restricted to P. vivax samples, as well as an associated viral segment of unknown function. These data, confirmed by PCR, are indicative of a novel RNA virus that we term Matryoshka RNA virus 1 (MaRNAV-1) to reflect its analogy to a "Russian doll": a virus, infecting a parasite, infecting an animal. Additional screening revealed that MaRNAV-1 was abundant in geographically diverse P. vivax derived from humans and mosquitoes, strongly supporting its association with this parasite, and not in any of the other Plasmodium samples analyzed here nor Anopheles mosquitoes in the absence of Plasmodium. Notably, related bi-segmented narnavirus-like sequences (MaRNAV-2) were retrieved from Australian birds infected with a Leucocytozoon-a genus of eukaryotic parasites that group with Plasmodium in the Apicomplexa subclass hematozoa. Together, these data support the establishment of two new phylogenetically divergent and genomically distinct viral species associated with protists, including the first virus likely infecting Plasmodium parasites. As well as broadening our understanding of the diversity and evolutionary history of the eukaryotic virosphere, the restriction to P. vivax may be of importance in understanding P. vivax-specific biology in humans and mosquitoes, and how viral co-infection might alter host responses at each stage of the P. vivax life-cycle.


Assuntos
Malária Vivax/parasitologia , Parasitos/genética , Plasmodium vivax/genética , Plasmodium/genética , Vírus de RNA/genética , Animais , Anopheles/parasitologia , Doenças das Aves , Humanos , Malária Falciparum/parasitologia , Plasmodium falciparum/genética
3.
J Virol ; 93(3)2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30404810

RESUMO

Understanding the microbiome of ticks in Australia is of considerable interest given the ongoing debate over whether Lyme disease and its causative agent, the bacterium Borrelia burgdorferisensu lato, are present in Australia. The diversity of bacteria infecting Australian ticks has been studied using both culture- and metagenomics-based techniques. However, little is known about the virome of Australian ticks, including whether this includes viruses with the potential to infect mammals. We used a meta-transcriptomics approach to reveal the diversity and evolution of viruses from Australian ticks collected from two locations on the central east coast of Australia, including metropolitan Sydney. From this we identified 19 novel RNA viruses belonging to 12 families, as well as 1 previously described RNA virus. The majority of these viruses were related to arthropod-associated viruses, suggesting that they do not utilize mammalian hosts. However, two novel viruses discovered in ticks feeding on bandicoot marsupials clustered closely within the mammal-associated hepacivirus and pestivirus groups (family Flaviviridae). Another bandicoot tick yielded a novel coltivirus (family Reoviridae), a group of largely tick-associated viruses containing the known human pathogen Colorado tick fever virus and its relative, Eyach virus. Importantly, our transcriptomic data provided no evidence for the presence of B. burgdorferisensu lato in any tick sample, providing further evidence against the presence of Lyme disease in Australia. In sum, this study reveals that Australian ticks harbor a diverse virome, including some viruses that merit additional screening in the context of emerging infectious disease.IMPORTANCE Each year a growing number of individuals along the east coast of Australia experience debilitating disease following tick bites. As there is no evidence for the presence of the causative agent of Lyme disease, Borrelia burgdorferisensu lato, in Australian ticks, the etiological basis of this disease syndrome remains controversial. To characterize the viruses associated with Australian ticks, particularly those that might be associated with mammalian infection, we performed unbiased RNA sequencing on 146 ticks collected across two locations along the coast of New South Wales, Australia. This revealed 19 novel RNA viruses from a diverse set of families. Notably, three of these viruses clustered with known mammalian viruses, including a novel coltivirus that was related to the human pathogen Colorado tick fever virus.


Assuntos
Genoma Viral , Doença de Lyme/epidemiologia , Infecções por Vírus de RNA/virologia , Vírus de RNA/classificação , Doenças Transmitidas por Carrapatos/transmissão , Carrapatos/virologia , Animais , Borrelia , Lagartos , Doença de Lyme/genética , Doença de Lyme/virologia , Marsupiais , Filogenia , Infecções por Vírus de RNA/genética , Vírus de RNA/genética , Vírus de RNA/isolamento & purificação , Ratos , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/virologia
4.
Emerg Infect Dis ; 23(7): 1198-1201, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28628459

RESUMO

The occurrence of Francisella tularensis outside of endemic areas, such as North America and Eurasia, has been enigmatic. We report the metagenomic discovery and isolation of F. tularensis ssp. holarctica biovar japonica from diseased ringtail possums in Sydney, Australia. This finding confirms the presence of F. tularensis in the Southern Hemisphere.


Assuntos
Doenças dos Animais/epidemiologia , Doenças dos Animais/microbiologia , Francisella tularensis , Marsupiais/microbiologia , Tularemia/veterinária , Animais , Austrália/epidemiologia , Francisella tularensis/genética , Francisella tularensis/isolamento & purificação , Genes Bacterianos , Humanos , Filogenia
5.
J Zoo Wildl Med ; 47(1): 45-55, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27010264

RESUMO

Egyptian fruit bats (Rousettus aegyptiacus) are one of many species within zoologic collections that frequently develop iron storage disease. The goals of this retrospective multi-institutional study were to determine the tissue distribution of iron storage in captive adult Egyptian fruit bats and the incidence of intercurrent neoplasia and infection, which may be directly or indirectly related to iron overload. Tissue sections from 83 adult Egyptian fruit bats were histologically evaluated by using tissue sections stained with hematoxylin and eosin, trichrome, and Prussian blue techniques. The liver and spleen consistently had the largest amount of iron, but significant amounts of iron were also detected in the pancreas, kidney, skeletal muscle, and lung. Hepatocellular carcinoma (HCC; 11) was the most common neoplasm, followed by cholangiocarcinoma (4). Extrahepatic neoplasms included bronchioloalveolar adenoma (3), pulmonary carcinosarcoma (1), oral sarcoma (1), renal adenocarcinoma (1), transitional cell carcinoma of the urinary bladder (1), mammary gland adenoma (1), and parathyroid adenoma (1). There were also metastatic neoplasms of undetermined primary origin that included three poorly differentiated carcinomas, a poorly differentiated sarcoma, and a neuroendocrine tumor. Bats with hemochromatosis were significantly more likely to have HCC than bats with hemosiderosis (P = 0.032). Cardiomyopathy was identified in 35/77 bats with evaluable heart tissue, but no direct association was found between cardiac damage and the amount of iron observed within the liver or heart. Hepatic abscesses occurred in multiple bats, although a significant association was not observed between hemochromatosis and bacterial infection. To the authors' knowledge, this is the first publication providing evidence of a positive correlation between hemochromatosis and HCC in any species other than humans.


Assuntos
Quirópteros , Hemocromatose/veterinária , Animais , Animais de Zoológico , Hemocromatose/patologia , Estudos Retrospectivos
6.
J Gen Virol ; 96(Pt 7): 1619-25, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25701824

RESUMO

Understanding the diversity of henipaviruses and related viruses is important in determining the viral ecology within flying-fox populations and assessing the potential threat posed by these agents. This study sought to identify the abundance and diversity of previously unknown paramyxoviruses (UPVs) in Australian flying-fox species (Pteropus alecto, Pteropus scapulatus, Pteropus poliocephalus and Pteropus conspicillatus) and in the Christmas Island species Pteropus melanotus natalis. Using a degenerative reverse transcription-PCR specific for the L gene of known species of the genus Henipavirus and two closely related paramyxovirus genera Respirovirus and Morbillivirus, we identified an abundance and diversity of previously UPVs, with a representative 31 UPVs clustering in eight distinct groups (100 UPVs/495 samples). No new henipaviruses were identified. The findings were consistent with a hypothesis of co-evolution of paramyxoviruses and their flying-fox hosts. Quantification of the degree of co-speciation between host and virus (beyond the scope of this study) would strengthen this hypothesis.


Assuntos
Evolução Biológica , Quirópteros/virologia , Variação Genética , Interações Hospedeiro-Patógeno , Paramyxoviridae/classificação , Paramyxoviridae/isolamento & purificação , Animais , Análise por Conglomerados , Dados de Sequência Molecular , Paramyxoviridae/genética , Filogenia , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Homologia de Sequência
7.
Mar Pollut Bull ; 204: 116520, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38815472

RESUMO

Metal and organic pollutants are prominent marine contaminants that disperse widely throughout the environment. Some contaminants biomagnify, leaving long-lived apex predators such as cetaceans at risk of toxicity. Various tissues collected post-mortem from 16 Ziphiidae individuals that stranded on the New South Wales (NSW) coast, Australia, over ∼15 years were investigated for 16 metals/metalloids and 33 organic contaminants. Polychlorinated biphenyls (PCBs) and Dichlorodiphenyltrichloroethanes (DDTs) were commonly detected in blubber and liver tissues. Mercury, cadmium and silver exceeded reported toxicity thresholds in several individuals. The liver tissue of a Mesoplodon layardii specimen had the highest mercury (386 mg/kg dry weight). Liver tissue of a Mesoplodon grayi specimen had the highest silver concentration (19.7 mg/kg dry weight), and the highest cadmium concentration was in Ziphius cavirostris kidney (478 mg/kg dry weight). This study provides important new information for rare Ziphiidae species globally.


Assuntos
Monitoramento Ambiental , Poluentes Químicos da Água , Animais , New South Wales , Poluentes Químicos da Água/análise , Bifenilos Policlorados/análise , Baleias , Fígado/química , Metais/análise
8.
Ecol Evol ; 14(8): e70149, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39157663

RESUMO

Mating systems, influenced by the social and ecological environment and individual attributes, are fundamental components of animal social organisation, impacting behaviour, animal distribution, ecosystem processes, individual reproductive success, and population dynamics. Bats are of particular interest for studies of mating systems as they are thought to exhibit a greater diversity in mating systems than any other mammalian order, and thus make great models for improving our fundamental understanding of causes and consequences of social organisation. Here, we review the current knowledge of bat mating systems. Our analyses show that research on bat mating systems has not kept pace with research on bats in general and that traditional typologies do not accommodate the mating system of several species. Therefore, we propose an alternative, functional framework to categorise mating systems of bats and by extension of other taxa. We argue that mating systems can be classified according to a male reproductive skew continuum, with an increasing skew from monogamy to true lekking. We include an additional category of lek-like mating system along the continuum to account for previous trans-categorical cases that have the appearance of resource defence but are functionally akin to a lek. The new framework has a total of seven categories: promiscuity, monogamy, female defence polygyny, resource defence polygyny, a lek-like mating system, exploded classical lek, and clustered classical lek. Applying this framework to bats reveals that lek mating systems are more prevalent in bats than previously recognised. It is our aim that this review and the proposed framework provide a greater understanding of bat mating systems particularly and provoke research into the factors that shape mating systems across animal taxa more generally.

9.
Sci Total Environ ; 930: 172526, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38636866

RESUMO

Pesticide contamination poses a significant threat to non-target wildlife, including amphibians, many of which are already highly threatened. This study assessed the extent of pesticide exposure in dead frogs collected during a mass mortality event across eastern New South Wales, Australia between July 2021 and March 2022. Liver tissue from 77 individual frogs of six species were analysed for >600 legacy and contemporary pesticides, including rodenticides. More than a third (36 %) of the liver samples contained at least one of the following pesticides: brodifacoum, dieldrin, DDE, heptachlor/heptachlor epoxide, fipronil sulfone, and 2-methyl-4-chlorophenoxyacetic acid (MCPA). Brodifacoum, a second-generation anticoagulant rodenticide, was found in four of the six frog species analysed: the eastern banjo frog (Limnodynastes dumerilii), cane toad (Rhinella marina), green tree frog (Litoria caerulea) and Peron's tree frog (Litoria peronii). This is the first report of anticoagulant rodenticide detected in wild amphibians, raising concerns about potential impacts on frogs and extending the list of taxa shown to accumulate rodenticides. Dieldrin, a banned legacy pesticide, was also detected in two species: striped marsh frog (Limnodynastes peronii) and green tree frog (Litoria caerulea). The toxicological effects of these pesticides on frogs are difficult to infer due to limited comparable studies; however, due to the low frequency of detection the presence of these pesticides was not considered a major contributing factor to the mass mortality event. Additional research is needed to investigate the effects of pesticide exposure on amphibians, particularly regarding the impacts of second-generation anticoagulant rodenticides. There is also need for continued monitoring and improved conservation management strategies for the mitigation of the potential threat of pesticide exposure and accumulation in amphibian populations.


Assuntos
Anticoagulantes , Anuros , Monitoramento Ambiental , Praguicidas , Rodenticidas , Animais , Rodenticidas/análise , Anticoagulantes/análise , New South Wales , Austrália
10.
Viruses ; 16(4)2024 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-38675993

RESUMO

Bellinger River virus (BRV) is a serpentovirus (nidovirus) that was likely responsible for the catastrophic mortality of the Australian freshwater turtle Myuchelys georgesi in February 2015. From November 2015 to November 2020, swabs were collected from turtles during repeated river surveys to estimate the prevalence of BRV RNA, identify risk factors associated with BRV infection, and refine sample collection. BRV RNA prevalence at first capture was significantly higher in M. georgesi (10.8%) than in a coexisting turtle, Emydura macquarii (1.0%). For M. georgesi, various risk factors were identified depending on the analysis method, but a positive BRV result was consistently associated with a larger body size. All turtles were asymptomatic when sampled and conjunctival swabs were inferred to be optimal for ongoing monitoring. Although the absence of disease and recent BRV detections suggests a reduced ongoing threat, the potential for the virus to persist in an endemic focus or resurge in cyclical epidemics cannot be excluded. Therefore, BRV is an ongoing potential threat to the conservation of M. georgesi, and strict adherence to biosecurity principles is essential to minimise the risk of reintroduction or spread of BRV or other pathogens.


Assuntos
Espécies em Perigo de Extinção , Tartarugas , Animais , Tartarugas/virologia , Austrália/epidemiologia , Nidovirales/genética , Nidovirales/isolamento & purificação , Infecções por Nidovirales/epidemiologia , Infecções por Nidovirales/veterinária , Infecções por Nidovirales/virologia , Prevalência , Filogenia , Rios/virologia , RNA Viral/genética , Fatores de Risco
11.
Commun Biol ; 7(1): 636, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38796620

RESUMO

The eastern quoll (Dasyurus viverrinus) is an endangered marsupial native to Australia. Since the extirpation of its mainland populations in the 20th century, wild eastern quolls have been restricted to two islands at the southern end of their historical range. Eastern quolls are the subject of captive breeding programs and attempts have been made to re-establish a population in mainland Australia. However, few resources currently exist to guide the genetic management of this species. Here, we generated a reference genome for the eastern quoll with gene annotations supported by multi-tissue transcriptomes. Our assembly is among the most complete marsupial genomes currently available. Using this assembly, we infer the species' demographic history, identifying potential evidence of a long-term decline beginning in the late Pleistocene. Finally, we identify a deletion at the ASIP locus that likely underpins pelage color differences between the eastern quoll and the closely related Tasmanian devil (Sarcophilus harrisii).


Assuntos
Espécies em Perigo de Extinção , Genoma , Marsupiais , Animais , Marsupiais/genética , Austrália , Pigmentação/genética , Evolução Biológica , Transcriptoma
12.
Virology ; 586: 43-55, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37487325

RESUMO

More than 70 bat species are found in mainland Australia. While most studies of bat viromes focus on sampling seemingly healthy individuals, little is known about the viruses and bacteria associated with diseased bats. We performed traditional diagnostic techniques and metatranscriptomic sequencing on tissue samples from 43 Australian bats, comprising three flying fox (Pteropodidae) and two microbat species experiencing a range of disease syndromes, including mass mortality, neurological signs, pneumonia and skin lesions. Of note, we identified the recently discovered Hervey pteropid gammaretrovirus in a bat with lymphoid leukemia, with evidence of replication consistent with an exogenous virus. The possible association of Hervey pteropid gammaretrovirus with lymphoid leukemia clearly merits additional investigation. One novel picornavirus and at least three new astroviruses and bat pegiviruses were also identified in a variety of tissue types, as well as a number of likely bacterial pathogens or opportunistic infections, most notably Pseudomonas aeruginosa.


Assuntos
Quirópteros , Gammaretrovirus , Pneumonia , Vírus de RNA , Humanos , Animais , Austrália/epidemiologia , Filogenia
13.
Sci Rep ; 13(1): 12512, 2023 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-37532795

RESUMO

Reliable information on population size is fundamental to the management of threatened species. For wild species, mark-recapture methods are a cornerstone of abundance estimation. Here, we show the first application of the close-kin mark-recapture (CKMR) method to a terrestrial species of high conservation value; the Christmas Island flying-fox (CIFF). The CIFF is the island's last remaining native terrestrial mammal and was recently listed as critically endangered. CKMR is a powerful tool for estimating the demographic parameters central to CIFF management and circumvents the complications arising from the species' cryptic nature, mobility, and difficult-to-survey habitat. To this end, we used genetic data from 450 CIFFs captured between 2015 and 2019 to detect kin pairs. We implemented a novel CKMR model that estimates sex-specific abundance, trend, and mortality and accommodates observations from the kin-pair distribution of male reproductive skew and mate persistence. CKMR estimated CIFF total adult female abundance to be approximately 2050 individuals (95% CI (950, 4300)). We showed that on average only 23% of the adult male population contributed to annual reproduction and strong evidence for between-year mate fidelity, an observation not previously quantified for a Pteropus species in the wild. Critically, our population estimates provide the most robust understanding of the status of this critically endangered population, informing immediate and future conservation initiatives.


Assuntos
Quirópteros , Conservação dos Recursos Naturais , Humanos , Animais , Masculino , Feminino , Espécies em Perigo de Extinção , Densidade Demográfica , Ecossistema , Mamíferos
14.
Emerg Infect Dis ; 18(7): 1159-62, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22709539

RESUMO

A community outbreak of gastroenteritis in Australia during 2007-2009 was caused by ingestion of playground sand contaminated with Salmonella enterica Paratyphi B, variant Java. The bacterium was also isolated from local wildlife. Findings support consideration of nonfood sources during salmonellosis outbreak investigations and indicate transmission through the animal-human interface.


Assuntos
Animais Selvagens/microbiologia , Surtos de Doenças , Jogos e Brinquedos , Salmonelose Animal/microbiologia , Infecções por Salmonella/epidemiologia , Salmonella paratyphi B/isolamento & purificação , Dióxido de Silício , Animais , Austrália/epidemiologia , Pré-Escolar , Humanos , Lactente , Febre Paratifoide/epidemiologia , Febre Paratifoide/microbiologia , Infecções por Salmonella/microbiologia , Infecções por Salmonella/transmissão , Salmonelose Animal/transmissão
15.
Parasitology ; 139(4): 478-96, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22260881

RESUMO

Two new myxosporean species in the gallbladders of frogs have recently spread across eastern Australia and cause disease. Cystodiscus axonis sp. n. and Cystodiscus australis sp. n. are species of Myxosporea (Myxozoa) identified from a range of Australian frogs and tadpoles including the introduced Cane toad (Rhinella marina). The new species are defined by their distinct genetic lineage, myxospore morphology and ultrastructure of the pre-sporogonic development. Spores of both species are produced in the gallbladder. Spores of C. axonis sp. n. possess distinct filiform polar appendages (FPA). The pre-sporogonic development of C. axonis sp. n. is within myelinated axons in the central nervous system of hosts, as well as bile ducts of tadpoles. Pre-sporogonic and sporogonic development of C. australis sp. n. is confined to tadpole bile ducts and myxospores of C. australis sp. n. are devoid of FPA. The genus Cystodiscus Lutz, 1889 introduced for Cystodiscus immersus Lutz, 1889 is emended to accompany myxosporean parasites affecting amphibians previously classified in the genus Myxidium sensu lato. A synopsis of described species within Cystodiscus is provided.


Assuntos
Anfíbios/parasitologia , Anuros/parasitologia , Vesícula Biliar/parasitologia , Myxozoa/classificação , Myxozoa/genética , Doenças Parasitárias em Animais/parasitologia , Animais , Ductos Biliares/parasitologia , Encéfalo/parasitologia , DNA de Protozoário/análise , DNA Espaçador Ribossômico/análise , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Multiplex , Myxozoa/isolamento & purificação , Myxozoa/ultraestrutura , Filogenia , Análise de Sequência de DNA , Especificidade da Espécie , Esporos de Protozoários/genética , Esporos de Protozoários/isolamento & purificação , Esporos de Protozoários/ultraestrutura
16.
Mov Ecol ; 10(1): 19, 2022 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-35410304

RESUMO

BACKGROUND: Animals are important vectors for the dispersal of a wide variety of plant species, and thus play a key role in maintaining the health and biodiversity of natural ecosystems. On oceanic islands, flying-foxes are often the only seed dispersers or pollinators. However, many flying-fox populations are currently in decline, particularly those of insular species, and this has consequences for the ecological services they provide. Knowledge of the drivers and the scale of flying-fox movements is important in determining the ecological roles that flying-foxes play on islands. This information is also useful for understanding the potential long-term consequences for forest dynamics resulting from population declines or extinction, and so can aid in the development of evidence-based ecological management strategies. To these ends, we examined the foraging movements, floral resource use, and social interactions of the Critically Endangered Christmas Island flying-fox (Pteropus natalis). METHODS: Utilization distributions, using movement-based kernel estimates (MBKE) were generated to determine nightly foraging movements of GPS-tracked P. natalis (n = 24). Generalized linear models (GLMs), linear mixed-effect models (LMMs), and Generalized linear mixed-effects model (GLMMs) were constructed to explain how intrinsic factors (body mass, skeletal size, and sex) affected the extent of foraging movements. In addition, we identified pollen collected from facial and body swabs of P. natalis (n = 216) to determine foraging resource use. Direct observations (n = 272) of foraging P. natalis enabled us to assess the various behaviors used to defend foraging resources. RESULTS: Larger P. natalis individuals spent more time foraging and less time traveling between foraging patches, traveled shorter nightly distances, and had smaller overall foraging ranges than smaller conspecifics. Additionally, larger individuals visited a lower diversity of floral resources. CONCLUSIONS: Our findings suggest that smaller P. natalis individuals are the primary vectors of long-distance dispersal of pollen and digested seeds in this species, providing a vital mechanism for maintaining the flow of plant genetic diversity across Christmas Island. Overall, our study highlights the need for more holistic research approaches that incorporate population demographics when assessing a species' ecological services.

17.
PLoS One ; 17(5): e0268549, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35613104

RESUMO

The black flying fox (Pteropus alecto) is a natural reservoir for Hendra virus, a paramyxovirus that causes fatal infections in humans and horses in Australia. Increased excretion of Hendra virus by flying foxes has been hypothesized to be associated with physiological or energetic stress in the reservoir hosts. The objective of this study was to explore the leukocyte profiles of wild-caught P. alecto, with a focus on describing the morphology of each cell type to facilitate identification for clinical purposes and future virus spillover research. To this end, we have created an atlas of images displaying the commonly observed morphological variations across each cell type. We provide quantitative and morphological information regarding the leukocyte profiles in bats captured at two roost sites located in Redcliffe and Toowoomba, Queensland, Australia, over the course of two years. We examined the morphology of leukocytes, platelets, and erythrocytes of P. alecto using cytochemical staining and characterization of blood films through light microscopy. Leukocyte profiles were broadly consistent with previous studies of P. alecto and other Pteropus species. A small proportion of individual samples presented evidence of hemoparasitic infection or leukocyte morphological traits that are relevant for future research on bat health, including unique large granular lymphocytes. Considering hematology is done by visual inspection of blood smears, examples of the varied cell morphologies are included as a visual guide. To the best of our knowledge, this study provides the first qualitative assessment of P. alecto leukocytes, as well as the first set of published hematology reference images for this species.


Assuntos
Quirópteros , Leucócitos , Animais , Quirópteros/imunologia , Vírus Hendra , Queensland
18.
Transbound Emerg Dis ; 69(5): e2366-e2377, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35491954

RESUMO

Due to their geographical isolation and small populations, insular bats may not be able to maintain acute immunizing viruses that rely on a large population for viral maintenance. Instead, endemic transmission may rely on viruses establishing persistent infections within hosts or inducing only short-lived neutralizing immunity. Therefore, studies on insular populations are valuable for developing broader understanding of viral maintenance in bats. The Christmas Island flying-fox (CIFF; Pteropus natalis) is endemic on Christmas Island, a remote Australian territory, and is an ideal model species to understand viral maintenance in small, geographically isolated bat populations. Serum or plasma (n = 190), oral swabs (n = 199), faeces (n = 31), urine (n = 32) and urine swabs (n = 25) were collected from 228 CIFFs. Samples were tested using multiplex serological and molecular assays, and attempts at virus isolation to determine the presence of paramyxoviruses, betacoronaviruses and Australian bat lyssavirus. Analysis of serological data provides evidence that the species is maintaining a pararubulavirus and a betacoronavirus. There was little serological evidence supporting the presence of active circulation of the other viruses assessed in the present study. No viral nucleic acid was detected and no viruses were isolated. Age-seropositivity results support the hypothesis that geographically isolated bat populations can maintain some paramyxoviruses and coronaviruses. Further studies are required to elucidate infection dynamics and characterize viruses in the CIFF. Lastly, apparent absence of some pathogens could have implications for the conservation of the CIFF if a novel disease were introduced into the population through human carriage or an invasive species. Adopting increased biosecurity protocols for ships porting on Christmas Island and for researchers and bat carers working with flying-foxes are recommended to decrease the risk of pathogen introduction and contribute to the health and conservation of the species.


Assuntos
Quirópteros , Lyssavirus , Ácidos Nucleicos , Animais , Austrália/epidemiologia , Betacoronavirus , Humanos
20.
One Health ; 13: 100360, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34917744

RESUMO

Invasive species exert a serious impact on native fauna and flora and have become the target of eradication and management efforts worldwide. Invasive avian species can also be important pathogen reservoirs, although their viromes and microbiomes have rarely been studied. As one of the top 100 invasive pest species globally, the expansion of Indian mynas (Acridotheres tristis) into peri-urban and rural environments, in conjunction with increasing free-ranging avian agricultural practices, may increase the risk of microbial pathogens jumping species boundaries. Herein, we used a meta-transcriptomic approach to explore the microbes present in brain, liver and large intestine of 16 invasive Indian myna birds in Sydney, Australia. From this, we discovered seven novel viruses from the families Adenoviridae, Caliciviridae, Flaviviridae, Parvoviridae and Picornaviridae. Interestingly, each of the novel viruses identified shared less than 80% genomic similarity with their closest relatives from other avian species, indicative of a lack of detectable virus transmission between invasive mynas to native or domestic species. Of note, we also identified two coccidian protozoa, Isospora superbusi and Isospora greineri, from the liver and gut tissues of mynas. Overall, these data demonstrate that invasive mynas can harbor a diversity of viruses and other microorganisms such that ongoing pathogen surveillance in this species is warranted.

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