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1.
Emerg Infect Dis ; 27(12): 3103-3110, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34808089

RESUMO

Anthrax is a disease of concern in many mammals, including humans. Management primarily consists of prevention through vaccination and tracking clinical-level observations because environmental isolation is laborious and bacterial distribution across large geographic areas difficult to confirm. Feral swine (Sus scrofa) are an invasive species with an extensive range in the southern United States that rarely succumbs to anthrax. We present evidence that feral swine might serve as biosentinels based on comparative seroprevalence in swine from historically defined anthrax-endemic and non-anthrax-endemic regions of Texas. Overall seropositivity was 43.7% (n = 478), and logistic regression revealed county endemicity status, age-class, sex, latitude, and longitude were informative for predicting antibody status. However, of these covariates, only latitude was statistically significant (ß = -0.153, p = 0.047). These results suggests anthrax exposure in swine, when paired with continuous location data, could serve as a proxy for bacterial presence in specific areas.

2.
Emerg Microbes Infect ; 10(1): 2199-2201, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34749583

RESUMO

We report pilot studies to evaluate the susceptibility of common domestic livestock (cattle, sheep, goat, alpaca, rabbit, and horse) to intranasal infection with SARS-CoV-2. None of the infected animals shed infectious virus via nasal, oral, or faecal routes, although viral RNA was detected in several animals. Further, neutralizing antibody titres were low or non-existent one month following infection. These results suggest that domestic livestock are unlikely to contribute to SARS-CoV-2 epidemiology.


Assuntos
COVID-19/veterinária , Especificidade de Hospedeiro , Gado/virologia , SARS-CoV-2/patogenicidade , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , COVID-19/imunologia , COVID-19/virologia , Camelídeos Americanos/virologia , Bovinos/virologia , Chlorocebus aethiops , Reservatórios de Doenças/virologia , Cabras/virologia , Cavalos/virologia , Especificidade de Hospedeiro/imunologia , Humanos , Cavidade Nasal/virologia , RNA Viral/análise , Coelhos/virologia , Reto/virologia , Sistema Respiratório/virologia , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Ovinos/virologia , Especificidade da Espécie , Células Vero , Eliminação de Partículas Virais , Vísceras/virologia
3.
NPJ Vaccines ; 6(1): 122, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34671047

RESUMO

Early in the SARS-CoV-2 pandemic concerns were raised regarding infection of new animal hosts and the effect on viral epidemiology. Infection of other animals could be detrimental by causing clinical disease, allowing further mutations, and bares the risk for the establishment of a non-human reservoir. Cats were the first reported animals susceptible to natural and experimental infection with SARS-CoV-2. Given the concerns these findings raised, and the close contact between humans and cats, we aimed to develop a vaccine candidate that could reduce SARS-CoV-2 infection and in addition to prevent spread among cats. Here we report that a Replicon Particle (RP) vaccine based on Venezuelan equine encephalitis virus, known to be safe and efficacious in a variety of animal species, could induce neutralizing antibody responses in guinea pigs and cats. The design of the SARS-CoV-2 spike immunogen was critical in developing a strong neutralizing antibody response. Vaccination of cats was able to induce high neutralizing antibody responses, effective also against the SARS-CoV-2 B.1.1.7 variant. Interestingly, in contrast to control animals, the infectious virus could not be detected in oropharyngeal or nasal swabs of vaccinated cats after SARS-CoV-2 challenge. Correspondingly, the challenged control cats spread the virus to in-contact cats whereas the vaccinated cats did not transmit the virus. The results show that the RP vaccine induces protective immunity preventing SARS-CoV-2 infection and transmission. These data suggest that this RP vaccine could be a multi-species vaccine useful to prevent infection and spread to and between animals should that approach be required.

4.
Proc Natl Acad Sci U S A ; 118(44)2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34716263

RESUMO

SARS-CoV-2 spillback from humans into domestic and wild animals has been well documented, and an accumulating number of studies illustrate that human-to-animal transmission is widespread in cats, mink, deer, and other species. Experimental inoculations of cats, mink, and ferrets have perpetuated transmission cycles. We sequenced full genomes of Vero cell-expanded SARS-CoV-2 inoculum and viruses recovered from cats (n = 6), dogs (n = 3), hamsters (n = 3), and a ferret (n = 1) following experimental exposure. Five nonsynonymous changes relative to the USA-WA1/2020 prototype strain were near fixation in the stock used for inoculation but had reverted to wild-type sequences at these sites in dogs, cats, and hamsters within 1- to 3-d postexposure. A total of 14 emergent variants (six in nonstructural genes, six in spike, and one each in orf8 and nucleocapsid) were detected in viruses recovered from animals. This included substitutions in spike residues H69, N501, and D614, which also vary in human lineages of concern. Even though a live virus was not cultured from dogs, substitutions in replicase genes were detected in amplified sequences. The rapid selection of SARS-CoV-2 variants in vitro and in vivo reveals residues with functional significance during host switching. These observations also illustrate the potential for spillback from animal hosts to accelerate the evolution of new viral lineages, findings of particular concern for dogs and cats living in households with COVID-19 patients. More generally, this glimpse into viral host switching reveals the unrealized rapidity and plasticity of viral evolution in experimental animal model systems.


Assuntos
COVID-19/virologia , Evolução Molecular , SARS-CoV-2/genética , Seleção Genética , Animais , COVID-19/veterinária , Gatos , Chlorocebus aethiops , Cães , Furões , Frequência do Gene , Animais de Estimação/virologia , SARS-CoV-2/patogenicidade , Células Vero , Proteínas Virais/genética
5.
Emerg Infect Dis ; 27(8): 2073-2080, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34286685

RESUMO

Wild animals have been implicated as the origin of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but it is largely unknown how the virus affects most wildlife species and if wildlife could ultimately serve as a reservoir for maintaining the virus outside the human population. We show that several common peridomestic species, including deer mice, bushy-tailed woodrats, and striped skunks, are susceptible to infection and can shed the virus in respiratory secretions. In contrast, we demonstrate that cottontail rabbits, fox squirrels, Wyoming ground squirrels, black-tailed prairie dogs, house mice, and racoons are not susceptible to SARS-CoV-2 infection. Our results expand the knowledge base of susceptible species and provide evidence that human-wildlife interactions could result in continued transmission of SARS-CoV-2.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Animais Selvagens , Suscetibilidade a Doenças , Humanos , Mamíferos , Camundongos
6.
J Med Entomol ; 58(2): 873-879, 2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33710315

RESUMO

Following the recent discovery of Bourbon virus (BRBV) as a human pathogen, and the isolation of the virus from Amblyomma americanum (L.) collected near the location of a fatal human case, we undertook a series of experiments to assess the laboratory vector competence of this tick species for BRBV. Larval ticks were infected using an immersion technique, and transstadial transmission of virus to the nymphal and then to the adult stages was demonstrated. Transstadially infected nymphs transmitted virus to adult ticks at very high rates during cofeeding, indicating the presence of infectious virus in the saliva of engorging ticks. Vertical transmission by transstadially infected females to their progeny occurred, but at a low rate. Rabbits fed on by infected ticks of all active life stages developed high titers of antibody to the virus, demonstrating host exposure to BRBV antigens/live virus during tick blood feeding. These results demonstrate that A. americanum is a competent vector of BRBV and indicate that cofeeding could be critical for enzootic maintenance.


Assuntos
Amblyomma/virologia , Infecções por Orthomyxoviridae/transmissão , Thogotovirus , Experimentação Animal , Animais , Vetores Aracnídeos/virologia , Vetores de Doenças , Ixodidae/virologia , Coelhos , Saliva/virologia
7.
Am J Trop Med Hyg ; 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33534764

RESUMO

Powassan virus (POWV) is a tick-borne virus maintained in sylvatic cycles between mammalian wildlife hosts and ticks (primarily Ixodes spp.). There are two currently recognized lineages, POWV-lineage 1 (POWV-L1) and deer tick virus (DTV; lineage 2), both of which can cause fatal neurologic disease in humans. Increased numbers of human case reports in the northeastern and north central United States in recent years have fueled questions into POWV epidemiology. We inoculated three candidate wildlife POWV reservoir hosts, groundhogs (Marmota monax), striped skunks (Mephitis mephitis), and fox squirrels (Sciurus niger), with either POWV-L1 or DTV. Resulting viremia, tissue tropism, and pathology were minimal in most inoculated individuals of all three species, with low (peak titer range, 101.7-103.3 plaque-forming units/mL serum) or undetectable viremia titers, lack of detection in tissues except for low titers in spleen, and seroconversion in most individuals by 21 days postinoculation (DPI). Pathology was limited and most commonly consisted of mild inflammation in the brain of POWV-L1- and DTV-inoculated skunks on four and 21 DPI, respectively. These results reveal variation in virulence and host competence among wild mammalian species, and a likely limited duration of host infectiousness to ticks during enzootic transmission cycles. However, POWV can transmit rapidly from tick to host, and tick co-feeding may be an additional transmission mechanism. The rare and low-level detections of viremia in these three, common, wild mammal species suggest that vector-host dynamics should continue to be explored, along with eco-epidemiological aspects of enzootic POWV transmission in different regions and virus lineages.

8.
J Wildl Dis ; 57(1): 51-59, 2021 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-33635996

RESUMO

Eastern populations of Ruffed Grouse (Bonasa umbellus) have been in a decades-long decline across the mid-Atlantic and southern Appalachian Mountains of the US. West Nile virus (WNV), which first arrived in the US in 1999, is suspected to have contributed to these declines based on decreased population indices since the arrival of WNV in Pennsylvania as well as on high, experimentally induced WNV-associated morbidity rates. A 3-yr statewide survey was conducted across Pennsylvania to measure flavivirus (i.e., WNV) seroprevalence among hunter-harvested grouse. The overall seroprevalence from 2015-17 was 14.4% (81/563); annual seroprevalence ranged from 2.8% (4/145) in the 2017 hunt year to 22.6% (52/230) in 2016-17. We analyzed the effects of numerous variables (i.e., Ruffed Grouse age and sex, hunt year, WNV vector index [VI], and region of Pennsylvania) on WNV serostatus by logistic regression. While there was no significant difference in WNV seroprevalence between sex and age group, there was significant variation in seroprevalence between geographic regions of Pennsylvania and across hunt years. Additionally, there was a negative correlation between WNV seroprevalence and VI. Low seroprevalence rates among Ruffed Grouse corresponded to years with a high VI, supporting experimental findings that Ruffed Grouse may be highly susceptible to WNV-associated disease. Additional strategic research efforts are essential to more effectively measure the effects of WNV on Ruffed Grouse and other vulnerable avian species.


Assuntos
Doenças das Aves/virologia , Culicidae/virologia , Galliformes , Febre do Nilo Ocidental/veterinária , Vírus do Nilo Ocidental , Animais , Animais Selvagens , Doenças das Aves/epidemiologia , Corvos/virologia , Feminino , Masculino , Mosquitos Vetores/virologia , Pennsylvania/epidemiologia , Dinâmica Populacional , Estudos Soroepidemiológicos , Febre do Nilo Ocidental/epidemiologia
9.
Proc Natl Acad Sci U S A ; 117(42): 26382-26388, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-32994343

RESUMO

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has reached nearly every country in the world with extraordinary person-to-person transmission. The most likely original source of the virus was spillover from an animal reservoir and subsequent adaptation to humans sometime during the winter of 2019 in Wuhan Province, China. Because of its genetic similarity to SARS-CoV-1, it is probable that this novel virus has a similar host range and receptor specificity. Due to concern for human-pet transmission, we investigated the susceptibility of domestic cats and dogs to infection and potential for infected cats to transmit to naive cats. We report that cats are highly susceptible to infection, with a prolonged period of oral and nasal viral shedding that is not accompanied by clinical signs, and are capable of direct contact transmission to other cats. These studies confirm that cats are susceptible to productive SARS-CoV-2 infection, but are unlikely to develop clinical disease. Further, we document that cats developed a robust neutralizing antibody response that prevented reinfection following a second viral challenge. Conversely, we found that dogs do not shed virus following infection but do seroconvert and mount an antiviral neutralizing antibody response. There is currently no evidence that cats or dogs play a significant role in human infection; however, reverse zoonosis is possible if infected owners expose their domestic pets to the virus during acute infection. Resistance to reinfection holds promise that a vaccine strategy may protect cats and, by extension, humans.


Assuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/virologia , Pneumonia Viral/virologia , Animais , Animais Domésticos , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Antígenos Virais/imunologia , Betacoronavirus/imunologia , COVID-19 , Gatos , Infecções por Coronavirus/patologia , Infecções por Coronavirus/transmissão , Modelos Animais de Doenças , Cães , Feminino , Masculino , Pandemias , Pneumonia Viral/patologia , Pneumonia Viral/transmissão , SARS-CoV-2 , Eliminação de Partículas Virais
10.
Am J Trop Med Hyg ; 103(5): 2100-2107, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32815506

RESUMO

Arthropod-borne viruses (arboviruses) are globally widespread, and their transmission cycles typically involve numerous vertebrate species. Serologic testing of animal hosts can provide a routine surveillance approach to monitoring animal disease systems, can provide a surveillance alternative to arthropod testing and human case reports, and may augment knowledge of epizootiology. Wild and captive ruminants represent good candidate sentinels to track geographic distribution and prevalence of select arboviruses. They often are geographically widespread and abundant, inhabit areas shared by humans and domestic animals, and are readily fed on by various hematophagous arthropod vectors. Ontario, Canada, is home to high densities of coexisting humans, livestock, and wild cervids, as well as growing numbers of arthropod vectors because of the effects of climate change. We collected blood samples from 349 livestock (cattle/sheep) and 217 cervids (wild/farmed/zoo) in Ontario (2016-2019) to assess for antibodies to zoonotic and agriculturally important arboviruses. Livestock sera were tested for antibodies to bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV). Sera from cervids were tested for antibodies to BTV, EHDV, West Nile virus (WNV), eastern equine encephalitis virus (EEEV), Powassan virus (POWV), and heartland virus (HRTV). Fifteen (9.0%) cattle were seropositive for EHDV-serotype 2. Nine (4.2%) cervids were seropositive for arboviruses; three confirmed as WNV, three as EEEV, and one as POWV. All animals were seronegative for BTV and HRTV. These results reveal low seroprevalence of important agricultural, wildlife, and zoonotic pathogens and underline the need for continued surveillance in this and other regions in the face of changing environmental conditions.


Assuntos
Arbovírus/imunologia , Vetores Artrópodes/virologia , Artrópodes/virologia , Ruminantes/virologia , Animais , Animais Domésticos , Animais Selvagens , Bovinos , Geografia , Gado , Ontário/epidemiologia , Estudos Soroepidemiológicos , Ovinos
11.
Microbiol Resour Announc ; 9(1)2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31896624

RESUMO

Pandoraea pnomenusa strain TF-18 was isolated from the roots of rice seedlings on selective medium containing four classes of antibiotics for isolation of Burkholderia pseudomallei Using Pacific Biosciences (PacBio) single-molecule real-time (SMRT) sequencing technology, we report here a complete genome of 5,499,432 bases, a GC content of 64.8%, and 4,849 coding sequences.

12.
J Med Entomol ; 56(6): 1463-1466, 2019 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-31549715

RESUMO

West Nile virus (WNV) (Flaviviridae: Flavivirus) was discovered in Africa more than 80 yr ago and became recognized as an avian pathogen and a cause of neurologic disease in horses largely during periodic incursions into Europe. Introduction of WNV into North America stimulated great anxiety, particularly in the equine industry, but also for pet owners and livestock producers concerned about the effect of WNV on other domestic animals. Numerous subsequent studies of naturally occurring and experimentally induced disease greatly expanded our understanding of the host range and clinical consequences of WNV infection in diverse species and led to rapid development and deployment of efficacious vaccines for horses. In addition to humans, horses are clearly the animals most frequently affected by serious, sometimes lethal disease following infection with WNV, but are dead-end hosts due to the low-magnitude viremia they develop. Dogs, cats, and livestock species including chickens are readily infected with WNV, but only occasionally develop clinical disease and are considered dead-end hosts for the virus.


Assuntos
Vacinação/veterinária , Vacinas Virais , Febre do Nilo Ocidental/veterinária , Vírus do Nilo Ocidental , Vacinas Virais/administração & dosagem , Vacinas Virais/análise , Febre do Nilo Ocidental/prevenção & controle
13.
Emerg Infect Dis ; 25(9): 1752-1753, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31441752

RESUMO

Since its recent discovery, Bourbon virus has been isolated from a human and ticks. To assess exposure of potential vertebrate reservoirs, we assayed banked serum and plasma samples from wildlife and domestic animals in Missouri, USA, for Bourbon virus-neutralizing antibodies. We detected high seroprevalence in raccoons (50%) and white-tailed deer (86%).


Assuntos
Reservatórios de Doenças , Thogotovirus/isolamento & purificação , Animais , Animais Domésticos/virologia , Animais Selvagens/virologia , Missouri
14.
Viruses ; 11(5)2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31117189

RESUMO

Although West Nile virus (WNV) is generally thought to circulate among mosquitoes and birds, several historic and recent works providing evidence of WNV activity in wild mammals have been published. Indeed, a previous review tabulated evidence of WNV exposure in at least 100 mammalian species. Herein, we provide an update on WNV activity in wild and select other mammals that have been reported since the last major review article on this subject was published in early 2013. Of interest, new species, such as Hoffman's two-toed sloths (Choloepus hoffmanni), are now included in the growing list of wild mammals that have been naturally exposed to WNV. Furthermore, new instances of WNV viremia as well as severe disease presumably caused by this virus have been reported in wild mammals (e.g., the Virginia opossum [Didelphis virginiana]) from natural and semi-captive (e.g., zoological institution) settings. Regrettably, few recent challenge studies have been conducted on wild mammals, which would provide key information as to their potential role(s) in WNV cycles. Largely based on these recent findings, important future lines of research are recommended to assess which mammalian species are commonly exposed to WNV, which mammal species develop viremias sufficient for infecting mosquitoes, and which mammal species might be negatively affected by WNV infection at the species or population level.


Assuntos
Doenças dos Animais/virologia , Animais Selvagens/virologia , Febre do Nilo Ocidental/veterinária , Vírus do Nilo Ocidental , Doenças dos Animais/transmissão , Animais , Exposição Ambiental , Mamíferos
15.
Transbound Emerg Dis ; 66(3): 1301-1305, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30740920

RESUMO

European starlings (Sturnus vulgaris), house sparrows (Passer domesticus) and rock pigeons (Columba livia) are all wild birds commonly found in large numbers in and around human dwellings and domestic livestock operations. This study evaluated the susceptibility of these species to three strains of highly pathogenic avian influenza virus (HP AIV) clade 2.3.4.4 isolated in the U.S.. Experimental infection of European starlings and rock pigeons did not result in any overt signs attributable to AIV infection and no virus shedding was detected from the oral and cloacal routes. House sparrows shed by the oral route and exhibited limited mortality. Individuals from all three species seroconverted following infection. These data suggest that none of these birds are a likely potential bridge host for future HP AIV outbreaks but that their seroconversion may be a useful surveillance tool for detection of circulating H5 HP AIV.


Assuntos
Surtos de Doenças/veterinária , Reservatórios de Doenças/veterinária , Vírus da Influenza A Subtipo H5N2/isolamento & purificação , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Influenza Aviária/epidemiologia , Animais , Animais Selvagens , Aves , Columbidae , Reservatórios de Doenças/virologia , Humanos , Vírus da Influenza A Subtipo H5N2/imunologia , Vírus da Influenza A Subtipo H5N2/patogenicidade , Vírus da Influenza A Subtipo H5N8/imunologia , Vírus da Influenza A Subtipo H5N8/patogenicidade , Vírus da Influenza A Subtipo H5N8/fisiologia , Influenza Aviária/virologia , Soroconversão , Pardais , Estorninhos , Estados Unidos/epidemiologia , Eliminação de Partículas Virais
16.
Transbound Emerg Dis ; 65(6): 1823-1827, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30014592

RESUMO

American robins (Turdus migratorius) are commonly associated with farmsteads in the United States and have shown previous evidence of exposure to an H5 avian influenza A virus (IAV) near a poultry production facility affected by a highly pathogenic (HP) H5 virus in Iowa, USA during 2015. We experimentally infected American robins with three clade 2.3.4.4 HP H5 viruses (H5N2 and H5N8). A total of 22/24 American robins shed virus, and all three strains were represented. The highest virus titres shed were 104.3 , 104.3 and 104.8 PFU/ml, associated respectively with viruses isolated from poultry, a captive gyrfalcon (Falco rusticolus), and a Northern pintail (Anas acuta). Of those birds that shed, viral shedding was initiated 1 or 2 days post-infection (DPI) and shedding ceased in all birds by 7 DPI. This study adds an additional synanthropic wildlife species to a growing list of animals that can successfully replicate and shed IAVs.


Assuntos
Vírus da Influenza A Subtipo H5N2/isolamento & purificação , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Influenza Aviária/virologia , Aves Canoras/virologia , Eliminação de Partículas Virais , Animais
17.
Am J Trop Med Hyg ; 99(2): 458-465, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29869604

RESUMO

Powassan virus (POWV) is a tick-borne zoonosis maintained in natural enzootic cycles between ixodid ticks and wild mammals. Reported human cases have increased in recent years; these infections can be fatal or lead to long-term neurologic sequelae. However, both the geographic distribution and the role of common, potential mammalian hosts in POWV transmission are poorly understood, creating challenges to public health surveillance. We looked for evidence of POWV infection among candidate wildlife host species and ticks collected from mammals and birds in southern Ontario. Tissues (including blood) and ticks from trapped wild mammals were collected in the summers of 2015 and 2016. Ticks removed from dogs in 2015-2016 and wildlife diagnostic cases from 2011 to 2013 were also included. Tissue and tick (Ixodes spp.) homogenates were tested for POWV by reverse transcriptase-polymerase chain reaction (RT-PCR). In addition, sera from wild mammals were tested for antibodies to POWV, West Nile virus (WNV), and heartland virus (HRTV) by plaque reduction neutralization test. All 724 tissue samples were negative for POWV by RT-PCR. One of 53 pools of Ixodes cookei (among 98 total tick pools) was RT-PCR positive for deer tick virus (POWV) lineage. Antibodies to POWV and WNV were detected in 0.4% of 265 and 6.1% of 264 samples, respectively, and all of 219 serum samples tested negative for anti-HRTV antibodies. These results reveal low POWV detection rates in southern Ontario, while highlighting the challenges and need for continued efforts into understanding POWV epidemiology and targeted surveillance strategies.


Assuntos
Animais Selvagens/virologia , Vetores Aracnídeos/virologia , Ixodidae/virologia , Zoonoses/transmissão , Animais , Arbovírus/isolamento & purificação , Aves/virologia , Cães/virologia , Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Encefalite Transmitida por Carrapatos/epidemiologia , Encefalite Transmitida por Carrapatos/virologia , Feminino , Masculino , Mamíferos/virologia , Ontário/epidemiologia , Phlebovirus/genética , Phlebovirus/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Zoonoses/epidemiologia , Zoonoses/virologia
18.
Arch Virol ; 163(10): 2823-2827, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29948379

RESUMO

During 2014-2015, clade 2.3.4.4 H5Nx highly pathogenic (HP) avian influenza A viruses (IAV) were first detected in North America and subsequently caused one of the largest agricultural emergencies in U.S. HISTORY: Recent evidence has suggested that cottontail rabbits can shed multiple IAV subtypes. We experimentally infected cottontail rabbits with three HP H5Nx IAVs. All rabbits tested shed virus on at least one day by at least one route. Cottontail rabbits appear to be an exception to the limited capacity for replication that has been previously reported for certain other mammalian species inoculated with clade 2.3.4.4 HP H5Nx avian influenza A viruses.


Assuntos
Vírus da Influenza A/isolamento & purificação , Vírus da Influenza A/fisiologia , Infecções por Orthomyxoviridae/veterinária , Coelhos/virologia , Eliminação de Partículas Virais , Animais , Vírus da Influenza A/genética , Vírus da Influenza A/patogenicidade , Infecções por Orthomyxoviridae/virologia , Virulência
19.
PLoS Negl Trop Dis ; 12(2): e0006302, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29447156

RESUMO

West Nile virus (WNV) and St. Louis encephalitis (SLEV) virus are enzootically maintained in North America in cycles involving the same mosquito vectors and similar avian hosts. However, these viruses exhibit dissimilar viremia and virulence phenotypes in birds: WNV is associated with high magnitude viremias that can result in mortality in certain species such as American crows (AMCRs, Corvus brachyrhynchos) whereas SLEV infection yields lower viremias that have not been associated with avian mortality. Cross-neutralization of these viruses in avian sera has been proposed to explain the reduced circulation of SLEV since the introduction of WNV in North America; however, in 2015, both viruses were the etiologic agents of concurrent human encephalitis outbreaks in Arizona, indicating the need to re-evaluate host factors and cross-neutralization responses as factors potentially affecting viral co-circulation. Reciprocal chimeric WNV and SLEV viruses were constructed by interchanging the pre-membrane (prM)-envelope (E) genes, and viruses subsequently generated were utilized herein for the inoculation of three different avian species: house sparrows (HOSPs; Passer domesticus), house finches (Haemorhous mexicanus) and AMCRs. Cross-protective immunity between parental and chimeric viruses were also assessed in HOSPs. Results indicated that the prM-E genes did not modulate avian replication or virulence differences between WNV and SLEV in any of the three avian species. However, WNV-prME proteins did dictate cross-protective immunity between these antigenically heterologous viruses. Our data provides further evidence of the important role that the WNV / SLEV viral non-structural genetic elements play in viral replication, avian host competence and virulence.


Assuntos
Doenças das Aves/virologia , Vírus da Encefalite de St. Louis/genética , Encefalite Viral/veterinária , Febre do Nilo Ocidental/veterinária , Vírus do Nilo Ocidental/genética , Animais , Doenças das Aves/imunologia , Doenças das Aves/mortalidade , Doenças das Aves/transmissão , Proteção Cruzada/imunologia , Corvos/virologia , Vírus da Encefalite de St. Louis/imunologia , Vírus da Encefalite de St. Louis/fisiologia , Encefalite Viral/imunologia , Encefalite Viral/transmissão , Encefalite Viral/virologia , Tentilhões/virologia , Interações Hospedeiro-Patógeno , Humanos , Fenótipo , Pardais/virologia , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/imunologia , Viremia , Virulência/genética , Replicação Viral , Febre do Nilo Ocidental/imunologia , Febre do Nilo Ocidental/transmissão , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/imunologia , Vírus do Nilo Ocidental/fisiologia
20.
Am J Trop Med Hyg ; 98(3): 841-844, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29313469

RESUMO

Chikungunya virus is an emerging arbovirus of significant human-health concern. Little is known about its sylvatic cycle, including whether ectothermic vertebrates are permissive to infection. In this study, individuals from ten species of reptiles and amphibians were inoculated with chikungunya virus and samples of blood were tested to characterize viremia and seroconversion. Viremia was not detected in cane toads, house geckos, or American alligators, but most of the green iguanas, red-eared sliders, ball and Burmese pythons, leopard frogs, Texas toads, and garter snakes developed viremia. Peak virus titers in serum of up to 4.5, 4.7, and 5.1 log10 plaque-forming units per milliliter were observed for garter snakes, ball pythons, and Texas toads, respectively. These results add to those of other studies that have suggested a possible role for ectothermic vertebrates in the ecology of arbovirus maintenance and transmission in nature.


Assuntos
Anfíbios/virologia , Febre de Chikungunya/veterinária , Vírus Chikungunya/patogenicidade , Reservatórios de Doenças/virologia , Répteis/virologia , Animais , Febre de Chikungunya/epidemiologia , Febre de Chikungunya/transmissão , Febre de Chikungunya/virologia , Vírus Chikungunya/crescimento & desenvolvimento , Especificidade de Hospedeiro , Humanos , Texas/epidemiologia , Carga Viral
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