Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
1.
Nucleic Acids Res ; 52(D1): D770-D776, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-37930838

RESUMO

Rhinovirus (RV), a prominent causative agent of both upper and lower respiratory diseases, ranks among the most prevalent human respiratory viruses. RV infections are associated with various illnesses, including colds, asthma exacerbations, croup and pneumonia, imposing significant and extended societal burdens. Characterized by a high mutation rate and genomic diversity, RV displays a diverse serological landscape, encompassing a total of 174 serotypes identified to date. Understanding RV genetic diversity is crucial for epidemiological surveillance and investigation of respiratory diseases. This study introduces a comprehensive and high-quality RV data resource, designated RVdb (http://rvdb.mgc.ac.cn), covering 26 909 currently identified RV strains, along with RV-related sequences, 3D protein structures and publications. Furthermore, this resource features a suite of web-based utilities optimized for easy browsing and searching, as well as automatic sequence annotation, multiple sequence alignment (MSA), phylogenetic tree construction, RVdb BLAST and a serotyping pipeline. Equipped with a user-friendly interface and integrated online bioinformatics tools, RVdb provides a convenient and powerful platform on which to analyse the genetic characteristics of RVs. Additionally, RVdb also supports the efforts of virologists and epidemiologists to monitor and trace both existing and emerging RV-related infectious conditions in a public health context.


Assuntos
Asma , Infecções por Enterovirus , Infecções por Picornaviridae , Rhinovirus , Humanos , Genômica , Filogenia , Infecções por Picornaviridae/genética , Rhinovirus/genética
2.
Sensors (Basel) ; 23(10)2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37430600

RESUMO

This paper is concerned with the problem of state estimation for nonlinear multi-sensor systems with cross-correlated noise and packet loss compensation. In this case, the cross-correlated noise is modeled by the synchronous correlation of the observation noise of each sensor, and the observation noise of each sensor is correlated with the process noise at the previous moment. Meanwhile, in the process of state estimation, since the measurement data may be transmitted in an unreliable network, data packet dropout will inevitably occur, leading to a reduction in estimation accuracy. To address this undesirable situation, this paper proposes a state estimation method for nonlinear multi-sensor systems with cross-correlated noise and packet dropout compensation based on a sequential fusion framework. Firstly, a prediction compensation mechanism and a strategy based on observation noise estimation are used to update the measurement data while avoiding the noise decorrelation step. Secondly, a design step for a sequential fusion state estimation filter is derived based on an innovation analysis method. Then, a numerical implementation of the sequential fusion state estimator is given based on the third-degree spherical-radial cubature rule. Finally, the univariate nonstationary growth model (UNGM) is combined with simulation to verify the effectiveness and feasibility of the proposed algorithm.

3.
Virol J ; 18(1): 14, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33430903

RESUMO

BACKGROUND: To identify site-specific features of amino acid substitutions that confer enhanced H7N9 virulence in humans, we independently generated mammalian-adapted variants of A/Anhui/1/2013 (AH-H7N9) and A/Shanghai/2/2013 (SH-H7N9) by serial passaging in Madin-Darby canine kidney (MDCK) cells. METHODS: Virus was respectively extracted from cell culture supernatant and cells, and was absolutely quantified by using real-time polymerase chain reaction. Viral RNAs were extracted and subjected to sequencing for identifying mutations. Then, site-specific mutations introduced by viral passaging were selected for further constructing HA7 or NA9 mutant plasmids, which were used to generate recombinant viruses. The interaction between the recombinant HA and receptors, H7N9-pseudotyped viruses and receptors were detected. RESULTS: Both subtypes displayed high variability in replicative capability and virulence during serial passaging. Analysis of viral genomes revealed multiple amino acid mutations in the hemagglutinin 7 (HA7) (A135T [AH-H7N9], T71I [SH-H7N9], T157I [SH-H7N9], T71I-V223I [SH-H7N9], T71I-T157I-V223I [SH-H7N9], and T71I-T157I-V223I-T40I [SH-H7N9]), and NA9 (N171S [AH-H7N9] and G335S [AH-H7N9]) proteins in various strains of the corresponding subtypes. Notably, quite a few amino acid substitutions indeed collectively strengthened the interactions between H7N9 strains and sialic acid receptors. Moreover, some of the amino acid substitutions identified were highly and specifically cytopathogenic to MDCK cells. CONCLUSIONS: This study demonstrated that AH-H7N9 and SH-H7N9 subtypes can acquire enhanced receptor affinity for sialic receptors through novel amino acid substitutions. Such changes in affinitive interactions are conferred by site-specific mutations of HA7 proteins that affect the virulence and pathology of the virus strain, and/or limited compatibility between the host and the virus strain.


Assuntos
Substituição de Aminoácidos , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/patogenicidade , Animais , China , Efeito Citopatogênico Viral , Cães , Subtipo H7N9 do Vírus da Influenza A/fisiologia , Células Madin Darby de Rim Canino , Mutação , Inoculações Seriadas , Virulência , Replicação Viral
4.
Nature ; 524(7563): 93-6, 2015 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-25970247

RESUMO

A novel Ebola virus (EBOV) first identified in March 2014 has infected more than 25,000 people in West Africa, resulting in more than 10,000 deaths. Preliminary analyses of genome sequences of 81 EBOV collected from March to June 2014 from Guinea and Sierra Leone suggest that the 2014 EBOV originated from an independent transmission event from its natural reservoir followed by sustained human-to-human infections. It has been reported that the EBOV genome variation might have an effect on the efficacy of sequence-based virus detection and candidate therapeutics. However, only limited viral information has been available since July 2014, when the outbreak entered a rapid growth phase. Here we describe 175 full-length EBOV genome sequences from five severely stricken districts in Sierra Leone from 28 September to 11 November 2014. We found that the 2014 EBOV has become more phylogenetically and genetically diverse from July to November 2014, characterized by the emergence of multiple novel lineages. The substitution rate for the 2014 EBOV was estimated to be 1.23 × 10(-3) substitutions per site per year (95% highest posterior density interval, 1.04 × 10(-3) to 1.41 × 10(-3) substitutions per site per year), approximating to that observed between previous EBOV outbreaks. The sharp increase in genetic diversity of the 2014 EBOV warrants extensive EBOV surveillance in Sierra Leone, Guinea and Liberia to better understand the viral evolution and transmission dynamics of the ongoing outbreak. These data will facilitate the international efforts to develop vaccines and therapeutics.


Assuntos
Ebolavirus/genética , Evolução Molecular , Variação Genética/genética , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/virologia , Sequência de Bases , Surtos de Doenças/estatística & dados numéricos , Ebolavirus/isolamento & purificação , Monitoramento Epidemiológico , Genoma Viral/genética , Doença pelo Vírus Ebola/transmissão , Humanos , Epidemiologia Molecular , Taxa de Mutação , Filogenia , Filogeografia , Serra Leoa/epidemiologia
5.
Sensors (Basel) ; 21(19)2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34640980

RESUMO

While monolithic giant earth observation satellites still have obvious advantages in regularity and accuracy, distributed satellite systems are providing increased flexibility, enhanced robustness, and improved responsiveness to structural and environmental changes. Due to increased system size and more complex applications, traditional centralized methods have difficulty in integrated management and rapid response needs of distributed systems. Aiming to efficient missions scheduling in distributed earth observation satellite systems, this paper addresses the problem through a networked game model based on a game-negotiation mechanism. In this model, each satellite is viewed as a "rational" player who continuously updates its own "action" through cooperation with neighbors until a Nash Equilibria is reached. To handle static and dynamic scheduling problems while cooperating with a distributed mission scheduling algorithm, we present an adaptive particle swarm optimization algorithm and adaptive tabu-search algorithm, respectively. Experimental results show that the proposed method can flexibly handle situations of different scales in static scheduling, and the performance of the algorithm will not decrease significantly as the problem scale increases; dynamic scheduling can be well accomplished with high observation payoff while maintaining the stability of the initial plan, which demonstrates the advantages of the proposed methods.

6.
Clin Infect Dis ; 63(10): 1288-1294, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27553371

RESUMO

BACKGROUND: During 2014-2015, an outbreak of Ebola virus disease (EVD) swept across parts of West Africa. No approved antiviral drugs are available for Ebola treatment currently. METHODS: A retrospective clinical case series was performed for EVD patients in Sierra Leone-China Friendship Hospital. Patients with confirmed EVD were sequentially enrolled and treated with either World Health Organization (WHO)-recommended supportive therapy (control group) from 10 to 30 October, or treated with WHO-recommended therapy plus favipiravir (T-705) from 1 to 10 November 2014. Survival and virological characteristics were observed for 85 patients in the control group and 39 in the T-705 treatment group. RESULTS: The overall survival rate in the T-705 treatment group was higher than that of the control group (56.4% [22/39] vs 35.3% [30/85]; P = .027). Among the 35 patients who finished all designed endpoint observations, the survival rate in the T-705 treatment group (64.8% [11/17]) was higher than that of the control group (27.8% [5/18]). Furthermore, the average survival time of the treatment group (46.9 ± 5.6 days) was longer than that of the control group (28.9 ± 4.7 days). Most symptoms of patients in the treatment group improved significantly. Additionally, 52.9% of patients who received T-705 had a >100-fold viral load reduction, compared with only 16.7% of patients in the control group. CONCLUSIONS: Treatment of EVD with T-705 was associated with prolonged survival and markedly reduced viral load, which makes a compelling case for further randomized controlled trials of T-705 for treating EVD.


Assuntos
Amidas/uso terapêutico , Antivirais/uso terapêutico , Ebolavirus , Doença pelo Vírus Ebola/tratamento farmacológico , Doença pelo Vírus Ebola/mortalidade , Pirazinas/uso terapêutico , Adolescente , Adulto , Feminino , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/virologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Estudos Retrospectivos , Serra Leoa/epidemiologia , Carga Viral , Adulto Jovem
7.
Eur Respir J ; 48(1): 168-78, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27230438

RESUMO

Prospective population data on the incidence of tuberculosis (TB) infection has been sparsely reported in the global literature.A population-based prospective study was conducted in rural China to investigate the annual risk of TB infection, and its persistence using serial tuberculin skin tests (TSTs) and an interferon-γ release assay. In total, 13 580 eligible participants from four rural sites, identified as TST negative (<10 mm) or QuantiFERON-TB Gold In-Tube (QFT) (an interferon-γ release assay) negative from a baseline survey, were included in the first year's follow-up examination.The annual conversion rate of QFT among the study sites ranged between 2.1% and 4.9% (average 3.1%), and the incidence of TST conversion ranged between 6.0% and 31.1% (average 14.5%). During the second year's follow-up, infection persistence was investigated using 390 subjects with QFT conversions. Among them, 49.7% (164 out of 330) were found to be consistently QFT positive. Both the conversion and the persistence of QFT positivity were found to be significantly increased with increasing age.In conclusion, the annual TB infection rate was suggested to be ∼1.5% based on persistent positive results after QFT conversion in rural China. Therefore, infection control among those high-risk populations, including the elderly, should be prioritised for TB control in China.


Assuntos
Tuberculose Latente/diagnóstico , Tuberculose Latente/epidemiologia , Programas de Rastreamento/métodos , População Rural , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , China/epidemiologia , Feminino , Humanos , Incidência , Testes de Liberação de Interferon-gama , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Distribuição por Sexo , Teste Tuberculínico , Adulto Jovem
9.
Emerg Infect Dis ; 21(11): 1921-7, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26485317

RESUMO

During 2014-2015, an outbreak of Ebola virus disease (EVD) swept across parts of West Africa. The China Mobile Laboratory Testing Team was dispatched to support response efforts; during September 28-November 11, 2014, they conducted PCR testing on samples from 1,635 suspected EVD patients. Of those patients, 50.4% were positive, of whom 84.6% lived within a 3-km zone along main roads connecting rural towns and densely populated cities. The median time from symptom onset to testing was 5 days. At testing, 75.7% of the confirmed patients had fever, and 94.1% reported at least 1 gastrointestinal symptom; all symptoms, except rash and hemorrhage, were more frequent in confirmed than nonconfirmed patients. Virus loads were significantly higher in EVD patients with fever, diarrhea, fatigue, or headache. The case-fatality rate was lower among patients 15-44 years of age and with virus loads of <100,000 RNA copies/mL. These findings are key for optimizing EVD control and treatment measures.


Assuntos
Surtos de Doenças , Ebolavirus/patogenicidade , Doença pelo Vírus Ebola/epidemiologia , Adolescente , Adulto , África Ocidental/epidemiologia , Criança , Pré-Escolar , Ebolavirus/genética , Feminino , Doença pelo Vírus Ebola/complicações , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Serra Leoa/epidemiologia , Adulto Jovem
10.
Emerg Infect Dis ; 20(9): 1541-3, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25148105

RESUMO

The recent emergence of human infection with influenza A(H10N8) virus is an urgent public health concern. Genomic analysis showed that the virus was conserved in chicken eggs but presented substantial adaptive mutations in MDCK cells. Our results provide additional evidence for the avian origin of this influenza virus.


Assuntos
Vírus da Influenza A Subtipo H10N8/genética , Mutação , Animais , Células Cultivadas , Embrião de Galinha , Galinhas , Cães , Genes Virais , Genoma Viral , Humanos , Vírus da Influenza A Subtipo H10N8/classificação , Vírus da Influenza A Subtipo H10N8/isolamento & purificação , Influenza Humana/virologia , Células Madin Darby de Rim Canino , Dados de Sequência Molecular
11.
Sci Rep ; 14(1): 6032, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38472260

RESUMO

The fitness function value is a kind of important information in the search process, which can be more targeted according to the guidance of the fitness function value. Most existing meta-heuristic algorithms only use the fitness function value as an indicator to compare the current variables as good or bad but do not use the fitness function value in the search process. To address this problem, the mathematical idea of the fitting is introduced into the meta-heuristic algorithm, and a symmetric projection optimizer (SPO) is proposed to solve numerical optimization and engineering problems more efficiently. The SPO algorithm mainly utilizes a new search mechanism, the symmetric projection search (SP) method. The SP method quickly completes the fitting of the projection plane, which is located through the symmetry of the two points and finds the minima in the projection plane according to the fitting result. Fitting by using the fitness function values allows the SP to find regions where extreme values may exist more quickly. Based on the SP method, exploration and exploitation strategies are constructed, respectively. The exploration strategy is used to find better regions, and the exploitation strategy is used to optimize the discovered regions continuously. The timing of the use of the two strategies is designed so that the SPO algorithm can converge faster while avoiding falling into local optima. The effectiveness of the SPO algorithm is extensively evaluated using seven test suites, including CEC2017, CEC2019, CEC2020, and CEC2022. It is also compared with two sets of 19 recent competitive algorithms. Statistical analyses are performed using five metrics such as the Wilcoxon test, the Friedman test, and variance. Finally, the practicality of the SPO algorithm is verified by four typical engineering problems and a real spacecraft trajectory optimization problem. The results show that the SPO algorithm can find superior results in 94.6% of the comparison tests and is a promising alternative for solving real-world problems.

12.
Virol Sin ; 38(2): 198-207, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36649817

RESUMO

Many paramyxoviruses are responsible for a variety of mild to severe human and animal diseases. Based on the novel discoveries over the past several decades, the family Paramyxoviridae infecting various hosts across the world includes 4 subfamilies, 17 classified genera and 78 species now. However, no systematic surveys of bat paramyxoviruses are available from the Chinese mainland. In this study, 13,064 samples from 54 bat species were collected and a comprehensive paramyxovirus survey was conducted. We obtained 94 new genome sequences distributed across paramyxoviruses from 22 bat species in seven provinces. Bayesian phylodynamic and phylogenetic analyses showed that there were four different lineages in the Jeilongvirus genus. Based on available data, results of host and region switches showed that the bat colony was partial to interior, whereas the rodent colony was exported, and the felines and hedgehogs were most likely the intermediate hosts from Scotophilus spp. rather than rodents. Based on the evolutionary trend, genus Jeilongvirus may have originated from Mus spp. in Australia, then transmitted to bats and rodents in Africa, Asia and Europe, and finally to bats and rodents in America.


Assuntos
Quirópteros , Camundongos , Animais , Humanos , Gatos , Filogenia , Teorema de Bayes , Paramyxoviridae/genética , China
13.
Microbiol Spectr ; 11(6): e0084023, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-37733296

RESUMO

IMPORTANCE: Based on clinical samples collected in China, we detected and reported 22 types for the first time in China, as well as three types for the first time in Asia, and reported their genetic characteristics and diversity. We identified a novel type of Rhinovirus (RV), A110, highlighting its unique genetic features. We annotated the genomic structure and serotype of all the existing RV sequences in the database, and four novel RV types were identified and their genetic diversity reported. Combined with the sequence annotation, we constructed a complete VP1 data set of RV and conducted the first large-scale evolutionary dynamics analysis of RV. Based on a high-quality data set, we conducted a comprehensive analysis of the guanine-cytosine (GC) content variations among serotypes of RVs. This study provides crucial theoretical support and valuable data for understanding RV's genetic diversity and developing antiviral strategies.


Assuntos
Infecções por Enterovirus , Infecções por Picornaviridae , Humanos , Rhinovirus/genética , Genômica , Filogenia , Variação Genética , Infecções por Picornaviridae/epidemiologia
14.
Front Microbiol ; 14: 1165839, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37564289

RESUMO

Introduction: Papillomaviruses (PVs) can cause hyperplasia in the skin and mucous membranes of humans, mammals, and non-mammalian animals, and are a significant risk factor for cervical and genital cancers. Methods: Using next-generation sequencing (NGS), we identified two novel strains of papillomavirus, PV-HMU-1 and PV-HMU-2, in swabs taken from belugas (Delphinapterus leucas) at Polar Ocean Parks in Qingdao and Dalian. Results: We amplified the complete genomes of both strains and screened ten belugas and one false killer whale (Pseudorca crassidens) for the late gene (L1) to determine the infection rate. In Qingdao, 50% of the two sampled belugas were infected with PV-HMU-1, while the false killer whale was negative. In Dalian, 71% of the eight sampled belugas were infected with PV-HMU-2. In their L1 genes, PV-HMU-1 and PV-HMU-2 showed 64.99 and 68.12% amino acid identity, respectively, with other members of Papillomaviridae. Phylogenetic analysis of combinatorial amino acid sequences revealed that PV-HMU-1 and PV-HMU-2 clustered with other known dolphin PVs but formed distinct branches. PVs carried by belugas were proposed as novel species under Firstpapillomavirinae. Conclusion: The discovery of these two novel PVs enhances our understanding of the genetic diversity of papillomaviruses and their impact on the beluga population.

15.
Natl Sci Rev ; 10(6): nwac213, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37425654

RESUMO

SARS-CoV and SARS-CoV-2 have been thought to originate from bats. In this study, we screened pharyngeal and anal swabs from 13 064 bats collected between 2016 and 2021 at 703 locations across China for sarbecoviruses, covering almost all known southern hotspots, and found 146 new bat sarbecoviruses. Phylogenetic analyses of all available sarbecoviruses show that there are three different lineages-L1 as SARS-CoV-related CoVs (SARSr-CoVs), L2 as SARS-CoV-2-related CoVs (SC2r-CoVs) and novel L-R (recombinants of L1 and L2)-present in Rhinolophus pusillus bats, in the mainland of China. Among the 146 sequences, only four are L-Rs. Importantly, none belong in the L2 lineage, indicating that circulation of SC2r-CoVs in China might be very limited. All remaining 142 sequences belong in the L1 lineage, of which YN2020B-G shares the highest overall sequence identity with SARS-CoV (95.8%). The observation suggests endemic circulations of SARSr-CoVs, but not SC2r-CoVs, in bats in China. Geographic analysis of the collection sites in this study, together with all published reports, indicates that SC2r-CoVs may be mainly present in bats of Southeast Asia, including the southern border of Yunnan province, but absent in all other regions within China. In contrast, SARSr-CoVs appear to have broader geographic distribution, with the highest genetic diversity and sequence identity to human sarbecoviruses along the southwest border of China. Our data provide the rationale for further extensive surveys in broader geographical regions within, and beyond, Southeast Asia in order to find the most recent ancestors of human sarbecoviruses.

16.
Virol Sin ; 38(5): 651-662, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37572844

RESUMO

The risk of emerging infectious diseases (EID) is increasing globally. More than 60% of EIDs worldwide are caused by animal-borne pathogens. This study aimed to characterize the virome, analyze the phylogenetic evolution, and determine the diversity of rodent-borne viruses in Hainan Province, China. We collected 682 anal and throat samples from rodents, combined them into 28 pools according to their species and location, and processed them for next-generation sequencing and bioinformatics analysis. The diverse viral contigs closely related to mammals were assigned to 22 viral families. Molecular clues of the important rodent-borne viruses were further identified by polymerase chain reaction for phylogenetic analysis and annotation of genetic characteristics such as arenavirus, coronavirus, astrovirus, pestivirus, parvovirus, and papillomavirus. We identified pestivirus and bocavirus in Leopoldoms edwardsi from Huangjinjiaoling, and bocavirus in Rattus andamanensis from the national nature reserves of Bangxi with low amino acid identity to known pathogens are proposed as the novel species, and their rodent hosts have not been previously reported to carry these viruses. These results expand our knowledge of viral classification and host range and suggest that there are highly diverse, undiscovered viruses that have evolved independently in their unique wildlife hosts in inaccessible areas.


Assuntos
Infecções por Parvoviridae , Vírus de RNA , Vírus , Humanos , Animais , Ratos , Roedores , Filogenia , Vírus/genética , Vírus de RNA/genética , China
17.
Front Microbiol ; 13: 845601, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35602043

RESUMO

Astroviruses infect human and animals and cause diarrhea, fever, and vomiting. In severe cases, these infections may be fatal in infants and juvenile animals. Previous evidence showed that humans in contact with infected animals can develop serological responses to astroviruses. Mamastrovirus 11 is a species of Mamastrovirus and was first reported in 2018. It was detected in the fecal samples of a California sea lion. The genome sequence of its capsid protein (CP) was submitted to GenBank. However, the genome sequence of its non-structural protein region was not elucidated. In the present study, we characterized the genome sequences of the novel astroviruses AstroV-HMU-1 and AstroV-like-HMU-2. These were obtained from California sea lions (Zalophus californianus) and walruses (Odobenus rosmarus) presenting with loose stools. A phylogenetic analysis revealed that the CP of AstroV-HMU-1 closely clustered with Mamastrovirus 11 while its RNA-dependent RNA polymerase (RdRp) and serine protease (SP) were closely related to the mink astrovirus in the genus Mamastrovirus. The genome of AstroV-HMU-1 provided basic information regarding the NS protein regions of Mamastrovirus 11. Recombination analyses showed that the genomes of Z. californianus AstroV-HMU-1, VA2/human and the mink astrovirus may have recombined long ago. The NS of AstroV-like-HMU-2 segregated from the Astroviridae in the deep root of the phylogenetic tree and exhibited 36% amino acid identity with other mamastroviruses. Thus, AstroV-like-HMU-2 was proposed as a member of a new genus in the unclassified Astroviridae. The present study suggested that that the loose stools of pinnipeds may be the result of occasional infection by this novel astrovirus. This discovery provides a scientific basis for future investigations into other animal-borne infectious diseases.

18.
Sheng Wu Gong Cheng Xue Bao ; 37(11): 4056-4065, 2021 Nov 25.
Artigo em Chinês | MEDLINE | ID: mdl-34841805

RESUMO

Photorhabdus is a Gram-negative bacterium from the family Enterobacteriaceae that lives in a symbiotic association with nematode or insects. In addition to the role of being insect pathogens, one species called Photorhabdus asymbiotica (Pa) causes human infection around the world. Nevertheless, how does this transkingdom infection occur remains elusive. Here we focus on one pathogenic determinant called Photorhabdus virulence cassette (PVC) that is founded in the Pa genome and many other pathogens. The RNA-seq and qPCR data showed that the NF-κB and MAPK pathways were drastically activated in the PVC-treated mammalian macrophages. Western blotting assays using samples treated with various inhibitors of the affected pathways confirmed the results we have observed for MAPK pathway previously. p65 translocation assays validated the NF-κB activation in the macrophages after PVC treatment. Moreover, the bacterial phagocytosis by macrophage was also promoted by PVC at the early stage, and this phagocytosis was inhibited by cytoskeleton inhibitors. Thus, the results indicated that PVC is involved in the bacterial invasion by activating NF-κB and MAPK signaling pathway, providing a new perspective for analyzing the pathogenicity of Pa in human infections.


Assuntos
Photorhabdus , Animais , Humanos , Macrófagos , NF-kappa B/genética , Transdução de Sinais , Virulência
19.
Virol Sin ; 36(4): 636-643, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33400094

RESUMO

Dengue virus is an arthropod-borne pathogen that is transmitted to humans primarily by Aedes spp. mosquitos, causing the acute infectious disease, dengue fever (DF). Until 2019, no dengue outbreak had been reported in Hainan Province for over 20 years. However, in early September of 2019, an increasing number of infected cases appeared and the DF outbreak lasted for over one month in Haikou City, Hainan Province. In our study, we collected 97 plasma samples from DF patients at three hospitals, as well as 1585 mosquito larvae samples from puddles in different areas of Haikou. There were 49 (50.5%) plasma samples found to be strongly positive and 9 (9.3%) plasma samples were weakly positive against the NS1 antigen. We discovered DENV both in the patient's plasma samples and mosquito larvae samples, and isolated the virus from C6/36 cells inoculated with the acute phase serum of patients. Phylogenetic analysis revealed that the new strains were the most closely related to the epidemic strain in the southern regions of China, belonging to lineage IV, genotype I, DENV-1. Compared to the seven closest strains from neighboring countries and provinces, a total of 18 amino acid mutations occurred in the coding sequences (CDS) of the new isolated strain, DENV1 HMU-HKU-2. Our data shows that dengue virus is re-emerged in Hainan, and pose new threats for public health. Thus regular molecular epidemiological surveillance is necessary for control and prevention of DENV transmission.


Assuntos
Aedes , Vírus da Dengue , Dengue , Animais , China/epidemiologia , Dengue/epidemiologia , Vírus da Dengue/genética , Surtos de Doenças , Genótipo , Humanos , Filogenia
20.
Microbiome ; 9(1): 18, 2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33478588

RESUMO

BACKGROUND: As the largest group of mammalian species, which are also widely distributed all over the world, rodents are the natural reservoirs for many diverse zoonotic viruses. A comprehensive understanding of the core virome of diverse rodents should therefore assist in efforts to reduce the risk of future emergence or re-emergence of rodent-borne zoonotic pathogens. RESULTS: This study aimed to describe the viral range that could be detected in the lungs of rodents from Mainland Southeast Asia. Lung samples were collected from 3284 rodents and insectivores of the orders Rodentia, Scandentia, and Eulipotyphla in eighteen provinces of Thailand, Lao PDR, and Cambodia throughout 2006-2018. Meta-transcriptomic analysis was used to outline the unique spectral characteristics of the mammalian viruses within these lungs and the ecological and genetic imprints of the novel viruses. Many mammalian- or arthropod-related viruses from distinct evolutionary lineages were reported for the first time in these species, and viruses related to known pathogens were characterized for their genomic and evolutionary characteristics, host species, and locations. CONCLUSIONS: These results expand our understanding of the core viromes of rodents and insectivores from Mainland Southeast Asia and suggest that a high diversity of viruses remains to be found in rodent species of this area. These findings, combined with our previous virome data from China, increase our knowledge of the viral community in wildlife and arthropod vectors in emerging disease hotspots of East and Southeast Asia. Video abstract.


Assuntos
Pulmão/virologia , RNA Viral/análise , Roedores/virologia , Viroma/genética , Animais , Sudeste Asiático , Insetos/virologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA