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1.
Proc Natl Acad Sci U S A ; 120(33): e2301926120, 2023 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-37552753

RESUMEN

Swine are a primary source for the emergence of pandemic influenza A viruses. The intensification of swine production, along with global trade, has amplified the transmission and zoonotic risk of swine influenza A virus (swIAV). Effective surveillance is essential to uncover emerging virus strains; however gaps remain in our understanding of the swIAV genomic landscape in Southeast Asia. More than 4,000 nasal swabs were collected from pigs in Cambodia, yielding 72 IAV-positive samples by RT-qPCR and 45 genomic sequences. We unmasked the cocirculation of multiple lineages of genetically diverse swIAV of pandemic concern. Genomic analyses revealed a novel European avian-like H1N2 swIAV reassortant variant with North American triple reassortant internal genes, that emerged approximately seven years before its first detection in pigs in 2021. Using phylogeographic reconstruction, we identified south central China as the dominant source of swine viruses disseminated to other regions in China and Southeast Asia. We also identified nine distinct swIAV lineages in Cambodia, which diverged from their closest ancestors between two and 15 B.P., indicating significant undetected diversity in the region, including reverse zoonoses of human H1N1/2009 pandemic and H3N2 viruses. A similar period of cryptic circulation of swIAVs occurred in the decades before the H1N1/2009 pandemic. The hidden diversity of swIAV observed here further emphasizes the complex underlying evolutionary processes present in this region, reinforcing the importance of genomic surveillance at the human-swine interface for early warning of disease emergence to avoid future pandemics.


Asunto(s)
Subtipo H1N1 del Virus de la Influenza A , Virus de la Influenza A , Gripe Humana , Infecciones por Orthomyxoviridae , Enfermedades de los Porcinos , Porcinos , Animales , Humanos , Subtipo H3N2 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/genética , Virus Reordenados/genética , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/veterinaria , Gripe Humana/epidemiología , Virus de la Influenza A/genética , Genómica , Filogenia , Cambodia/epidemiología , Enfermedades de los Porcinos/epidemiología
2.
PLoS Pathog ; 18(8): e1010763, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35939522

RESUMEN

Transmembrane Protein 41B (TMEM41B) and Vacuole Membrane Protein 1 (VMP1) are two ER-associated lipid scramblases that play a role in autophagosome formation and cellular lipid metabolism. TMEM41B is also a recently validated host factor required by flaviviruses and coronaviruses. However, the exact underlying mechanism of TMEM41B in promoting viral infections remains an open question. Here, we validated that both TMEM41B and VMP1 are essential host dependency factors for all four serotypes of dengue virus (DENV) and human coronavirus OC43 (HCoV-OC43), but not chikungunya virus (CHIKV). While HCoV-OC43 failed to replicate entirely in both TMEM41B- and VMP1-deficient cells, we detected diminished levels of DENV infections in these cell lines, which were accompanied by upregulation of the innate immune dsRNA sensors, RIG-I and MDA5. Nonetheless, this upregulation did not correspondingly induce the downstream effector TBK1 activation and Interferon-beta expression. Despite low levels of DENV replication, classical DENV replication organelles were undetectable in the infected TMEM41B-deficient cells, suggesting that the upregulation of the dsRNA sensors is likely a consequence of aberrant viral replication rather than a causal factor for reduced DENV infection. Intriguingly, we uncovered that the inhibitory effect of TMEM41B deficiency on DENV replication, but not HCoV-OC43, can be partially reversed using exogenous fatty acid supplements. In contrast, VMP1 deficiency cannot be rescued using the metabolite treatment. In line with the observed phenotypes, we found that both TMEM41B- and VMP1-deficient cells harbor higher levels of compromised mitochondria, especially in VMP1 deficiency which results in severe dysregulations of mitochondrial beta-oxidation. Using a metabolomic profiling approach, we revealed distinctive global dysregulations of the cellular metabolome, particularly lipidome, in TMEM41B- and VMP1-deficient cells. Our findings highlight a central role for TMEM41B and VMP1 in modulating multiple cellular pathways, including lipid mobilization, mitochondrial beta-oxidation, and global metabolic regulations, to facilitate the replication of flaviviruses and coronaviruses.


Asunto(s)
Infecciones por Coronavirus , Coronavirus , Dengue , Metabolismo Energético , Humanos , Lípidos , Proteínas de la Membrana/genética , Replicación Viral
3.
Phys Chem Chem Phys ; 26(16): 12453-12466, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38625536

RESUMEN

The impact of ionic liquids (ILs) on polar reactions is well recognised, however the impact of ILs on non-polar reactions is less well understood or explored. Pericyclic Cope rearrangements are highly concerted, exhibit minimal charge localisation and pass through an uncharged but well-defined transition state, and thus provide a good mechanism for exploring the impact of IL polarizability on chemical reactivity. Recently, a 10× rate enhancement has been observed for the Cope rearrangement of 3-phenyl-1,5-hexadiene in the IL 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C4C1im][NTf2] compared to benzene. In this work we undertake a DFT based computational study (B3LYP-D3BJ/6-311+G(d,p) and M06-2X-D3/6-311+G(d,p)) of the Cope rearrangement of 3-phenyl-1,5-hexadiene and 3-propyl-hexa-1,5-diene in molecular solvents (acetonitrile, benzene and ethanol) and the IL [C4C1im][NTf2] using the SMD solvation model. The impact of benzene and [C4C1im][NTf2] on the Cope rearrangement of 3-phenyl-1,5-hexadiene is studied in more detail and we provide insight into the reason for the rate enhancement in an IL. The volume of activation is evaluated and the potential impact of 'solvent pressure' is discussed. We identify two potential mechanisms for volume effects to contribute to the rate enhancement. Solvent association energies are evaluated at the DLNPO-CCSD(T) level. Specific solvent interactions are explored through atomic partial charge, molecular orbital and bond critical point analysis, as well as via non-colvalent interaction (NCI) plots, electrostatic potential (ESP) differences and density difference Δρ(r) plots. We find that the cation and anion together form an extensive van der Waals pocket in-which the transition state (TS) sits. Electron density within the TS is anisotropically polarised via a 'push-pull' effect due to the dual cation-anion nature of the IL, stabilising the TS relative to benzene. We also provide experimental evidence that these effects are generalisable to other ILs. Overall, our aim is to provide a deeper moleuclar level understanding of the impact of ILs on non-polar reactions.

4.
J Gambl Stud ; 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38724824

RESUMEN

Computer technology has long been touted as a means of increasing the effectiveness of voluntary self-exclusion schemes - especially in terms of relieving gaming venue staff of the task of manually identifying and verifying the status of new customers. This paper reports on the government-led implementation of facial recognition technology as part of an automated self-exclusion program in the city of Adelaide in South Australia-one of the first jurisdiction-wide enforcements of this controversial technology in small venue gambling. Drawing on stakeholder interviews, site visits and documentary analysis over a two year period, the paper contrasts initial claims that facial recognition offered a straightforward and benign improvement to the efficiency of the city's long-running self-excluded gambler program, with subsequent concerns that the new technology was associated with heightened inconsistencies, inefficiencies and uncertainties. As such, the paper contends that regardless of the enthusiasms of government, tech industry and gaming lobby, facial recognition does not offer a ready 'technical fix' to problem gambling. The South Australian case illustrates how this technology does not appear to better address the core issues underpinning problem gambling, and/or substantially improve conditions for problem gamblers to refrain from gambling. As such, it is concluded that the gambling sector needs to pay close attention to the practical outcomes arising from initial cases such as this, and resist industry pressures for the wider replication of this technology in other jurisdictions.

5.
J Org Chem ; 88(13): 9565-9568, 2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37319431

RESUMEN

A new visible-light-driven method for the carboxylation of (hetero)aryl/vinyl bromides has been developed using catalytic 4CzIPN, nickel, phenyl triflimide, and sodium formate as a carboxylation agent. Interestingly, we found catalytic phenyl triflimide plays an essential role in promoting the reaction. While many C(sp2) carboxylation reactions require harsh reagents or gaseous carbon dioxide, we demonstrate the mild and facile construction of carboxylic acids from readily available starting materials.


Asunto(s)
Bromuros , Níquel , Formiatos , Catálisis
6.
Proc Natl Acad Sci U S A ; 117(1): 619-628, 2020 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-31843889

RESUMEN

Influenza B viruses have circulated in humans for over 80 y, causing a significant disease burden. Two antigenically distinct lineages ("B/Victoria/2/87-like" and "B/Yamagata/16/88-like," termed Victoria and Yamagata) emerged in the 1970s and have cocirculated since 2001. Since 2015 both lineages have shown unusually high levels of epidemic activity, the reasons for which are unclear. By analyzing over 12,000 influenza B virus genomes, we describe the processes enabling the long-term success and recent resurgence of epidemics due to influenza B virus. We show that following prolonged diversification, both lineages underwent selective sweeps across the genome and have subsequently taken alternate evolutionary trajectories to exhibit epidemic dominance, with no reassortment between lineages. Hemagglutinin deletion variants emerged concomitantly in multiple Victoria virus clades and persisted through epistatic mutations and interclade reassortment-a phenomenon previously only observed in the 1970s when Victoria and Yamagata lineages emerged. For Yamagata viruses, antigenic drift of neuraminidase was a major driver of epidemic activity, indicating that neuraminidase-based vaccines and cross-reactivity assays should be employed to monitor and develop robust protection against influenza B morbidity and mortality. Overall, we show that long-term diversification and infrequent selective sweeps, coupled with the reemergence of hemagglutinin deletion variants and antigenic drift of neuraminidase, are factors that contributed to successful circulation of diverse influenza B clades. Further divergence of hemagglutinin variants with poor cross-reactivity could potentially lead to circulation of 3 or more distinct influenza B viruses, further complicating influenza vaccine formulation and highlighting the urgent need for universal influenza vaccines.


Asunto(s)
Enfermedades Transmisibles Emergentes/virología , Epidemias/prevención & control , Evolución Molecular , Virus de la Influenza B/genética , Vacunas contra la Influenza/uso terapéutico , Gripe Humana/virología , Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/inmunología , Enfermedades Transmisibles Emergentes/prevención & control , Variación Genética , Genoma Viral/genética , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Humanos , Virus de la Influenza B/inmunología , Virus de la Influenza B/patogenicidad , Gripe Humana/epidemiología , Gripe Humana/inmunología , Gripe Humana/prevención & control , Neuraminidasa/genética , Neuraminidasa/inmunología , Selección Genética/inmunología
7.
J Am Chem Soc ; 143(24): 8987-8992, 2021 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-34102836

RESUMEN

We developed an effective method for reductive radical formation that utilizes the radical anion of carbon dioxide (CO2•-) as a powerful single electron reductant. Through a polarity matched hydrogen atom transfer (HAT) between an electrophilic radical and a formate salt, CO2•- formation occurs as a key element in a new radical chain reaction. Here, radical chain initiation can be performed through photochemical or thermal means, and we illustrate the ability of this approach to accomplish reductive activation of a range of substrate classes. Specifically, we employed this strategy in the intermolecular hydroarylation of unactivated alkenes with (hetero)aryl chlorides/bromides, radical deamination of arylammonium salts, aliphatic ketyl radical formation, and sulfonamide cleavage. We show that the reactivity of CO2•- with electron-poor olefins results in either single electron reduction or alkene hydrocarboxylation, where substrate reduction potentials can be utilized to predict reaction outcome.


Asunto(s)
Dióxido de Carbono/química , Aniones/química , Radicales Libres/química , Estructura Molecular , Oxidación-Reducción
8.
Lancet ; 396(10251): 603-611, 2020 08 29.
Artículo en Inglés | MEDLINE | ID: mdl-32822564

RESUMEN

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with a 382-nucleotide deletion (∆382) in the open reading frame 8 (ORF8) region of the genome have been detected in Singapore and other countries. We investigated the effect of this deletion on the clinical features of infection. METHODS: We retrospectively identified patients who had been screened for the ∆382 variant and recruited to the PROTECT study-a prospective observational cohort study conducted at seven public hospitals in Singapore. We collected clinical, laboratory, and radiological data from patients' electronic medical records and serial blood and respiratory samples taken during hospitalisation and after discharge. Individuals infected with the ∆382 variant were compared with those infected with wild-type SARS-CoV-2. Exact logistic regression was used to examine the association between the infection groups and the development of hypoxia requiring supplemental oxygen (an indicator of severe COVID-19, the primary endpoint). Follow-up for the study's primary endpoint is completed. FINDINGS: Between Jan 22 and March 21, 2020, 278 patients with PCR-confirmed SARS-CoV-2 infection were screened for the ∆382 deletion and 131 were enrolled onto the study, of whom 92 (70%) were infected with the wild-type virus, ten (8%) had a mix of wild-type and ∆382-variant viruses, and 29 (22%) had only the ∆382 variant. Development of hypoxia requiring supplemental oxygen was less frequent in the ∆382 variant group (0 [0%] of 29 patients) than in the wild-type only group (26 [28%] of 92; absolute difference 28% [95% CI 14-28]). After adjusting for age and presence of comorbidities, infection with the ∆382 variant only was associated with lower odds of developing hypoxia requiring supplemental oxygen (adjusted odds ratio 0·07 [95% CI 0·00-0·48]) compared with infection with wild-type virus only. INTERPRETATION: The ∆382 variant of SARS-CoV-2 seems to be associated with a milder infection. The observed clinical effects of deletions in ORF8 could have implications for the development of treatments and vaccines. FUNDING: National Medical Research Council Singapore.


Asunto(s)
Infecciones por Coronavirus/virología , Eliminación de Gen , Genoma Viral/genética , Neumonía Viral/virología , Adulto , Anciano , Betacoronavirus , COVID-19 , Infecciones por Coronavirus/complicaciones , Infecciones por Coronavirus/epidemiología , Humanos , Hipoxia/etiología , Hipoxia/terapia , Persona de Mediana Edad , Sistemas de Lectura Abierta , Pandemias , Neumonía Viral/complicaciones , Neumonía Viral/epidemiología , Estudios Prospectivos , Terapia Respiratoria , SARS-CoV-2 , Índice de Severidad de la Enfermedad , Singapur/epidemiología , Replicación Viral
9.
Cell Mol Life Sci ; 77(8): 1607-1622, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31352533

RESUMEN

Natural reservoir hosts can sustain infection of pathogens without succumbing to overt disease. Multiple bat species host a plethora of viruses, pathogenic to other mammals, without clinical symptoms. Here, we detail infection of bat primary cells, immune cells, and cell lines with Dengue virus. While antibodies and viral RNA were previously detected in wild bats, their ability to sustain infection is not conclusive. Old-world fruitbat cells can be infected, producing high titres of virus with limited cellular responses. In addition, there is minimal interferon (IFN) response in cells infected with MOIs leading to dengue production. The ability to support in vitro replication/production raises the possibility of bats as a transient host in the life cycle of dengue or similar flaviviruses. New antibody serology evidence from Asia/Pacific highlights the previous exposure and raises awareness that bats may be involved in flavivirus dynamics and infection of other hosts.


Asunto(s)
Quirópteros/virología , Virus del Dengue/fisiología , Dengue/veterinaria , Animales , Australasia/epidemiología , Línea Celular , Quirópteros/inmunología , Dengue/epidemiología , Dengue/inmunología , Virus del Dengue/inmunología , Interacciones Huésped-Patógeno , Inmunidad Innata , Malasia/epidemiología , Internalización del Virus
10.
J Nat Prod ; 83(1): 174-178, 2020 01 24.
Artículo en Inglés | MEDLINE | ID: mdl-31904956

RESUMEN

This study began with the goal of identifying additional constituents from Zyzzya fuliginosa extracts obtained from an Indo-Pacific sponge (coll. no. 06132). The previous work identified several red and green pyrroloiminiquinones (aka pyrrolo[4,3,2-de]quinolines), and this reinvestigation provided two additional analogues, a blue compound named zyzzamine A (1) and a green compound named zyzzamine B (2). The relatively low ratio of H/[sum(CNO)] = 0.71 or 0.76 of this pair greatly complicated the final steps of compound characterization and required the use of five 2D NMR strategies and MS2 data sets.


Asunto(s)
Poríferos/química , Quinolinas/química , Animales , Espectroscopía de Resonancia Magnética , Estructura Molecular , Protones
11.
J Med Internet Res ; 22(9): e19256, 2020 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-32924959

RESUMEN

BACKGROUND: One of the promises of digital health is to better engage patients and improve care for vulnerable populations. Patients with drug use disorders are a vulnerable population who often do not receive the care they need, both for their drug use disorders as well as their other health care needs. Appropriate primary care for patients with drug use disorders needs to be patient-centered, holistic, highly accessible, and engaging. The electronic Case-finding and Help Assessment Tool (eCHAT) was designed as a patient-centered tool for the identification and measurement of problematic health behaviors and mood states. OBJECTIVE: The aim of this study was to explore the patient experience of eCHAT at an Australian family medicine clinic for patients with drug use disorders. METHODS: A total of 12 semistructured interviews were conducted with patients, two interviews were conducted with doctors, and one focus group was conducted with patient advocates who were former patients of the clinic where the study took place. The transcripts were analyzed using inductive thematic analysis. RESULTS: The key themes identified from the interviews and the focus group were as follows: (1) eCHAT helped reduce stigma related to drug use in the doctor-patient consultation, (2) restricted answer options impacted the ability of patients to tell their stories, (3) patient-related response factors, (4) increased efficiency in the consultation process, and (5) divergence in level of concern around security and privacy. CONCLUSIONS: eCHAT has the potential to help vulnerable patients in primary care to engage more with their doctors and reduce experiences of stigma. eCHAT may be a useful digital health intervention in a family medicine clinic for patients with drug use disorders. It has the potential to improve patient engagement and access to health care, which are crucial areas of need in this vulnerable population. However, it is important to clearly communicate the privacy risk of digital health tools and to implement eCHAT such that it will add value to, rather than displace, in-person consultations with the family doctor.


Asunto(s)
Evaluación de Necesidades/normas , Trastornos Relacionados con Sustancias/terapia , Telemedicina/métodos , Femenino , Humanos , Masculino , Investigación Cualitativa
12.
13.
Br Med Bull ; 132(1): 81-95, 2019 12 11.
Artículo en Inglés | MEDLINE | ID: mdl-31848585

RESUMEN

BACKGROUND: Human infections with avian influenza viruses (AIV) represent a persistent public health threat. The principal risk factor governing human infection with AIV is from direct contact with infected poultry and is primarily observed in Asia and Egypt where live-bird markets are common. AREAS OF AGREEMENT: Changing patterns of virus transmission and a lack of obvious disease manifestations in avian species hampers early detection and efficient control of potentially zoonotic AIV. AREAS OF CONTROVERSY: Despite extensive studies on biological and environmental risk factors, the exact conditions required for cross-species transmission from avian species to humans remain largely unknown. GROWING POINTS: The development of a universal ('across-subtype') influenza vaccine and effective antiviral therapeutics are a priority. AREAS TIMELY FOR DEVELOPING RESEARCH: Sustained virus surveillance and collection of ecological and physiological parameters from birds in different environments is required to better understand influenza virus ecology and identify risk factors for human infection.


Asunto(s)
Gripe Aviar/epidemiología , Gripe Humana/epidemiología , Animales , Antivirales/uso terapéutico , Aves , Brotes de Enfermedades , Susceptibilidad a Enfermedades , Humanos , Virus de la Influenza A/clasificación , Vacunas contra la Influenza , Gripe Aviar/terapia , Gripe Aviar/transmisión , Gripe Humana/terapia , Gripe Humana/transmisión , Factores de Riesgo , Zoonosis/epidemiología , Zoonosis/terapia , Zoonosis/transmisión
14.
PLoS Pathog ; 13(2): e1006203, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-28170438

RESUMEN

We characterise the evolutionary dynamics of influenza infection described by viral sequence data collected from two challenge studies conducted in human hosts. Viral sequence data were collected at regular intervals from infected hosts. Changes in the sequence data observed across time show that the within-host evolution of the virus was driven by the reversion of variants acquired during previous passaging of the virus. Treatment of some patients with oseltamivir on the first day of infection did not lead to the emergence of drug resistance variants in patients. Using an evolutionary model, we inferred the effective rate of reassortment between viral segments, measuring the extent to which randomly chosen viruses within the host exchange genetic material. We find strong evidence that the rate of effective reassortment is low, such that genetic associations between polymorphic loci in different segments are preserved during the course of an infection in a manner not compatible with epistasis. Combining our evidence with that of previous studies we suggest that spatial heterogeneity in the viral population may reduce the extent to which reassortment is observed. Our results do not contradict previous findings of high rates of viral reassortment in vitro and in small animal studies, but indicate that in human hosts the effective rate of reassortment may be substantially more limited.


Asunto(s)
Gripe Humana/virología , Modelos Genéticos , Orthomyxoviridae/genética , Humanos , Selección Genética
15.
BMC Infect Dis ; 19(1): 231, 2019 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-30845930

RESUMEN

BACKGROUND: Although Indonesia has high fatality rate of human A/H5N1 cases, epidemiological and clinical data on influenza virus circulation among humans has been limited. Within Indonesia, Bali province is of interest due to high population densities of humans, pigs and poultry. This study aims to characterize and compare the epidemiological and clinical patterns of influenza viruses in humans through surveillance among patients with influenza-like illness (ILI) in Bali, Indonesia. METHODS: ILI patients were recruited at 21 sentinel health facilities across all nine regencies in Bali, from July 2010 to June 2014. PCR-based assays were used for detection and subtyping of influenza viruses. Demographic, behavioural and clinical data were tested for associations with influenza using chi-squared tests and logistic regression. RESULTS: Of 2077 ILI patients, 291 (14.0%) tested positive for influenza A, 152 (7.3%) for influenza B, and 16 (0.77%) for both influenza A and B. Of the influenza A isolates, the majority 61.2% were A/H3N2, followed by A/H1N1-pdm09 (80; 26.1%). Two A/H5N1 were identified. Influenza positive rates were significantly higher during wet season months (28.3%), compared with the dry season (13.8%; χ2 = 61.1; df = 1; p < 0.0001). Clinical predictors for infection varied by virus type, with measured fever (≥38 °C) more strongly associated with influenza B (AOR: 1.62; 95% CI: 1.10, 2.39). CONCLUSION: Influenza circulates year-round among humans in Bali with higher activity during the wet season. High contact rates with poultry and pigs, along with influenza virus detection that could not be subtyped through conventional assays, highlight the need for molecular studies to characterize epidemiological and evolutionary dynamics of influenza in this setting.


Asunto(s)
Betainfluenzavirus/genética , Virus de la Influenza A/genética , Gripe Humana/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Indonesia/epidemiología , Lactante , Recién Nacido , Virus de la Influenza A/aislamiento & purificación , Gripe Humana/epidemiología , Gripe Humana/virología , Betainfluenzavirus/aislamiento & purificación , Modelos Logísticos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Estaciones del Año , Adulto Joven
16.
Emerg Infect Dis ; 24(1): 114-117, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29260678

RESUMEN

To determine whether fruit bats in Singapore have been exposed to filoviruses, we screened 409 serum samples from bats of 3 species by using a multiplex assay that detects antibodies against filoviruses. Positive samples reacted with glycoproteins from Bundibugyo, Ebola, and Sudan viruses, indicating filovirus circulation among bats in Southeast Asia.


Asunto(s)
Quirópteros/sangre , Quirópteros/virología , Ebolavirus , Marburgvirus , Proteínas del Envoltorio Viral/sangre , Animales , Glicoproteínas/sangre , Glicoproteínas/genética , Glicoproteínas/aislamiento & purificación , Estudios Seroepidemiológicos , Singapur/epidemiología
17.
PLoS Pathog ; 12(5): e1005620, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27166585

RESUMEN

Despite evidence for avian influenza A virus (AIV) transmission between wild and domestic ecosystems, the roles of bird migration and poultry trade in the spread of viruses remain enigmatic. In this study, we integrate ecosystem interactions into a phylogeographic model to assess the contribution of wild and domestic hosts to AIV distribution and persistence. Analysis of globally sampled AIV datasets shows frequent two-way transmission between wild and domestic ecosystems. In general, viral flow from domestic to wild bird populations was restricted to within a geographic region. In contrast, spillover from wild to domestic populations occurred both within and between regions. Wild birds mediated long-distance dispersal at intercontinental scales whereas viral spread among poultry populations was a major driver of regional spread. Viral spread between poultry flocks frequently originated from persistent lineages circulating in regions of intensive poultry production. Our analysis of long-term surveillance data demonstrates that meaningful insights can be inferred from integrating ecosystem into phylogeographic reconstructions that may be consequential for pandemic preparedness and livestock protection.


Asunto(s)
Aves/virología , Virus de la Influenza A , Gripe Aviar/epidemiología , Pandemias/veterinaria , Aves de Corral/virología , Animales , Animales Salvajes/virología , Ecosistema , Filogeografía
18.
J Virol ; 90(24): 11247-11258, 2016 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-27707932

RESUMEN

Knowledge of influenza virus evolution at the point of transmission and at the intrahost level remains limited, particularly for human hosts. Here, we analyze a unique viral data set of next-generation sequencing (NGS) samples generated from a human influenza challenge study wherein 17 healthy subjects were inoculated with cell- and egg-passaged virus. Nasal wash samples collected from 7 of these subjects were successfully deep sequenced. From these, we characterized changes in the subjects' viral populations during infection and identified differences between the virus in these samples and the viral stock used to inoculate the subjects. We first calculated pairwise genetic distances between the subjects' nasal wash samples, the viral stock, and the influenza virus A/Wisconsin/67/2005 (H3N2) reference strain used to generate the stock virus. These distances revealed that considerable viral evolution occurred at various points in the human challenge study. Further quantitative analyses indicated that (i) the viral stock contained genetic variants that originated and likely were selected for during the passaging process, (ii) direct intranasal inoculation with the viral stock resulted in a selective bottleneck that reduced nonsynonymous genetic diversity in the viral hemagglutinin and nucleoprotein, and (iii) intrahost viral evolution continued over the course of infection. These intrahost evolutionary dynamics were dominated by purifying selection. Our findings indicate that rapid viral evolution can occur during acute influenza infection in otherwise healthy human hosts when the founding population size of the virus is large, as is the case with direct intranasal inoculation. IMPORTANCE: Influenza viruses circulating among humans are known to rapidly evolve over time. However, little is known about how influenza virus evolves across single transmission events and over the course of a single infection. To address these issues, we analyze influenza virus sequences from a human challenge experiment that initiated infection with a cell- and egg-passaged viral stock, which appeared to have adapted during its preparation. We find that the subjects' viral populations differ genetically from the viral stock, with subjects' viral populations having lower representation of the amino-acid-changing variants that arose during viral preparation. We also find that most of the viral evolution occurring over single infections is characterized by further decreases in the frequencies of these amino-acid-changing variants and that only limited intrahost genetic diversification through new mutations is apparent. Our findings indicate that influenza virus populations can undergo rapid genetic changes during acute human infections.


Asunto(s)
Variación Genética , Genoma Viral , Subtipo H3N2 del Virus de la Influenza A/genética , ARN Viral/genética , Animales , Pollos , Evolución Molecular , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Subtipo H3N2 del Virus de la Influenza A/crecimiento & desarrollo , Gripe Humana/virología , Modelos Genéticos , Selección Genética , Cigoto/virología
19.
Arch Virol ; 162(9): 2843-2846, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28577214

RESUMEN

Newcastle disease virus (NDV) is an important pathogen in poultry. Waterfowl and a number of other avian species serve as the host for NDV. Severity of the disease is variable and infected animals mainly develop respiratory and neurological symptoms. Outbreaks of NDV in poultry are recorded regularly in the Republic of Kazakhstan despite the widespread use of vaccines. Here we present evidence that nucleic acid found in open water bodies in Kazakhstan can be detected by means of next-generation sequencing and belongs to at least three distinct genotypes of NDV.


Asunto(s)
Enfermedad de Newcastle/virología , Virus de la Enfermedad de Newcastle/genética , Animales , Microbiología Ambiental , Kazajstán/epidemiología , Enfermedad de Newcastle/epidemiología , Filogenia , Aves de Corral , ARN Viral/genética
20.
Nature ; 473(7348): 519-22, 2011 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-21614079

RESUMEN

Swine influenza A viruses (SwIV) cause significant economic losses in animal husbandry as well as instances of human disease and occasionally give rise to human pandemics, including that caused by the H1N1/2009 virus. The lack of systematic and longitudinal influenza surveillance in pigs has hampered attempts to reconstruct the origins of this pandemic. Most existing swine data were derived from opportunistic samples collected from diseased pigs in disparate geographical regions, not from prospective studies in defined locations, hence the evolutionary and transmission dynamics of SwIV are poorly understood. Here we quantify the epidemiological, genetic and antigenic dynamics of SwIV in Hong Kong using a data set of more than 650 SwIV isolates and more than 800 swine sera from 12 years of systematic surveillance in this region, supplemented with data stretching back 34 years. Intercontinental virus movement has led to reassortment and lineage replacement, creating an antigenically and genetically diverse virus population whose dynamics are quantitatively different from those previously observed for human influenza viruses. Our findings indicate that increased antigenic drift is associated with reassortment events and offer insights into the emergence of influenza viruses with epidemic potential in swine and humans.


Asunto(s)
Evolución Molecular , Subtipo H1N1 del Virus de la Influenza A/fisiología , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/transmisión , Enfermedades de los Porcinos/virología , Porcinos/virología , Zoonosis/virología , Animales , Aves/virología , Femenino , Hong Kong/epidemiología , Humanos , Subtipo H1N1 del Virus de la Influenza A/clasificación , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/transmisión , Gripe Aviar/virología , Gripe Humana/epidemiología , Gripe Humana/transmisión , Gripe Humana/virología , Masculino , Epidemiología Molecular , Datos de Secuencia Molecular , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/transmisión , Infecciones por Orthomyxoviridae/virología , Filogenia , Vigilancia de la Población , Virus Reordenados/genética , Virus Reordenados/inmunología , Virus Reordenados/aislamiento & purificación , Virus Reordenados/fisiología , Porcinos/sangre , Enfermedades de los Porcinos/sangre , Enfermedades de los Porcinos/epidemiología , Zoonosis/epidemiología , Zoonosis/transmisión
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