Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.326
Filtrar
1.
Viruses ; 13(2)2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33530573

RESUMO

Sapovirus is a common cause of acute gastroenteritis in all age groups. Sapovirus infections are seldom investigated in Spain, and its epidemiology in the country is not well known. The use of molecular diagnostic procedures has allowed a more frequent detection of sapoviruses in patients with diarrhea. A total of 2545 stool samples from patients with acute gastroenteritis attended from June 2018 to February 2020 at the Clinic University Hospital in Valencia, Spain, were analyzed by reverse transcription (RT) and real-time multiplex PCR (RT-PCR) to investigate the etiology of enteric infections. Sapovirus was the second enteric virus detected with a positive rate of 8%, behind norovirus (12.2%) and ahead of rotavirus (7.1%), astrovirus (4.9%) and enteric adenoviruses (2.9%). Most sapovirus infections occurred in infants and young children under 3 years of age (74%) with the highest prevalence in autumn and early winter. Coinfections were found in 25% of the patients with sapovirus diarrhea, mainly with other enteric viruses. Genotyping demonstrated the circulation of seven different genotypes during the study period, with a predominance of genotypes GI.1, GI.2, and GII.1. Phylogenetic analysis showed that genogroup GII strains form a cluster separated from genogroup GI and GV, being genotype GV.1 strains related to genotype GI.1 and GI.2 strains.


Assuntos
Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/virologia , Gastroenterite/epidemiologia , Gastroenterite/virologia , Sapovirus/genética , Fatores Etários , Infecções por Caliciviridae/diagnóstico , Coinfecção/epidemiologia , Coinfecção/microbiologia , Coinfecção/virologia , Diarreia/diagnóstico , Diarreia/epidemiologia , Diarreia/virologia , Feminino , Gastroenterite/diagnóstico , Variação Genética , Genótipo , Humanos , Masculino , Epidemiologia Molecular , Reação em Cadeia da Polimerase Multiplex , Filogenia , Prevalência , RNA Viral/genética , Sapovirus/classificação , Sapovirus/isolamento & purificação , Estações do Ano , Espanha/epidemiologia
2.
Talanta ; 225: 121978, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33592726

RESUMO

In modern times, viruses still threaten people's lives. Among them, norovirus was the main pathogenic factor in the cause of gastroenteritis and foodborne illness, of which the GII.4 and GII.17 genotypes are prevalent in China and most parts of the world. A simple and low-cost platform for rapid and accurate norovirus detection remains a major challenge. After the cell-free system and paper-based chromogenic system were optimized, a rapid and specific norovirus detection method was established based on norovirus-specific sequences in combination with toehold switch elements. The development of a visible color change during detection eliminates the need for any complicated instruments. We validated this strategy and its specificity in differentiating GII.4, GII.17, Zika virus, and human coronavirus HKU1. The results showed that the optimized detection system not only provided a simple and rapid detection method for the sufficient differentiation of the two norovirus genotypes but also showed high specificity and no cross-reactivity with other viruses. Using nucleic acid isothermal amplification, this assay showed a limit of detection of 0.5 pM for the GII.4 genotype and 2.6 fM for the GII.17 genotype in reactions that could be observed directly with the naked eye. Our results suggested that this paper-based colorimetric method could serve as a simple and low-cost visual detection method for pathogens in clinical samples, especially in remote or rural areas.


Assuntos
Infecções por Caliciviridae/diagnóstico , Colorimetria/métodos , Gastroenterite/diagnóstico , Infecções por Caliciviridae/virologia , Colorimetria/economia , Colorimetria/instrumentação , Análise Custo-Benefício , Gastroenterite/virologia , Genótipo , Humanos , Norovirus/genética , Norovirus/fisiologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Papel , RNA Viral/genética , Sensibilidade e Especificidade
3.
Artigo em Inglês | MEDLINE | ID: mdl-33573536

RESUMO

Abstract: Significant reductions in the incidence of enteroviruses and noroviruses, both transmitted primarily by the faecal-oral route, were noted in 2020 compared to the previous decade, in Victoria, Australia. The enterovirus specimen positivity rate was reduced by 84.2% in 2020, while the norovirus outbreak positivity rate declined by 49.0%. The most likely explanation for these reductions is the concurrence of social restrictions, physical distancing, personal hygiene awareness and international and domestic border closures in response to the COVID-19 pandemic.


Assuntos
/epidemiologia , Infecções por Caliciviridae/virologia , Enterovirus , Gastroenterite/epidemiologia , Gastroenterite/virologia , Norovirus , Infecções por Caliciviridae/epidemiologia , Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/virologia , Humanos , Incidência , Vitória/epidemiologia
4.
BMC Infect Dis ; 21(1): 54, 2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33435906

RESUMO

BACKGROUND: An outbreak of acute gastroenteritis occurred in a kindergarten located Shenzhen City on March 4, 2018. We were invited to investigate to the risk factors associated with this outbreak. METHODS: We conducted retrospective cohort-studies on three different groups of subjects in order to figure out the difference of incidence of acute gastroenteritis among subjects of different activities on March 2: group one consisted of people who attended the Lantern festival activities; group two consisted of children and employees who ate breakfast and bread provided by the kindergarten; and groups three consisted of children and employees who did not eat breakfast or bread provided by the kindergarten. Fecal, anal swabs, dishware swabs and hand swabs specimens were collected in the study. Bacteria known to cause acute gastroenteritis were cultured. Viruses associated with acute gastroenteritis were tested using real-time PCR. Capsid gene fragment of 557 bp of norovirus was amplified and sequenced. The phylogenetic tree was constructed with MEGA 7.0 using neighbor-joining method based on capsid gene fragment of norovirus. RESULTS: A total of 143 suspected cases were identified in this outbreak. Diarrhea happened more often in adults than in children while emesis and bellyache were more frequently found in children than in adults. Higher AGE incidence was observed in group 2, children and employees who had breakfast in the kindergarten on March 2, as well as in group 3, and among employees who eating bread involved in breakfast provided on March 2. Five anal swab specimens were positive for norovirus. All noroviruses belongs to group II.3 and have an identity more than 99%. CONCLUSION: A chef, as an asymptomatic carrier with norovirus, was the infectious resource in this outbreak. He contaminated breakfast food provided on March 2. Although morning check is implemented in kindergartens of China, employees are often excluded in morning check. Our finding highlights the importance of morning check covering employees and periodical training for cooks.


Assuntos
Desjejum , Infecções por Caliciviridae/epidemiologia , Portador Sadio/virologia , Surtos de Doenças , Manipulação de Alimentos , Gastroenterite/epidemiologia , Norovirus/genética , Escolas Maternais , Adulto , Infecções por Caliciviridae/diagnóstico , Infecções por Caliciviridae/prevenção & controle , Infecções por Caliciviridae/virologia , Criança , Pré-Escolar , China/epidemiologia , Diarreia/epidemiologia , Diarreia/virologia , Fezes/virologia , Feminino , Microbiologia de Alimentos/métodos , Gastroenterite/diagnóstico , Gastroenterite/prevenção & controle , Gastroenterite/virologia , Humanos , Incidência , Masculino , Filogenia , Quarentena/métodos , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , Fatores de Risco , Vômito/epidemiologia , Vômito/virologia
5.
Vet Res Commun ; 45(1): 31-40, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33392909

RESUMO

Gastrointestinal disorders caused by enteric viruses are frequently reported in dogs worldwide, with significant mortality rates in unvaccinated individuals. This study reports the identification and molecular characterization of Canine parvovirus (CPV-2), Canine coronavirus (CcoV), Canine astrovirus (AstV), and Canine calicivirus (CcaV) in a panel of dogs showing severe enteric clinical signs sampled in a typical Mediterranean environment (Sardinia, Italy). At least one of these viral species was detected in 92.3% samples. CPV-2 was the most frequently detected virus (87.2%), followed by AsTv (20.5%), CCoV-IIa (18%), and CCoV-I (10.3%). CCoV-IIb and CaCV were not detected in any sample. Single infection was detected in 24 samples (66.7%), mainly related to CPV-2 (91.7%). Coinfections were present in 33.3% samples with constant detection of CPV-2. Canine coronavirus was present only in coinfected animals. The VP2 sequence analysis of CPV-2 positive samples confirmed the presence of all variants, with CPV-2b most frequently detected. Phylogeny based on the CcoV-IIa spike protein (S) gene allowed to identify 2 different clades among Sardinian isolates but failed to distinguish enteric from pantropic viruses. Study on presence and prevalence of enteroviruses in dogs increase our knowledge about the circulation of these pathogens in the Mediterranean area and highlight the need for dedicated routine vaccine prophylaxis. Molecular analyses of enteric viruses are fundamental to avoid failure of vaccines caused by frequent mutations observed in these enteroviruses.


Assuntos
Infecções por Astroviridae/veterinária , Infecções por Caliciviridae/veterinária , Infecções por Coronavirus/veterinária , Doenças do Cão/virologia , Infecções por Parvoviridae/veterinária , Animais , Astroviridae/genética , Astroviridae/isolamento & purificação , Infecções por Astroviridae/epidemiologia , Infecções por Astroviridae/virologia , Caliciviridae/genética , Caliciviridae/isolamento & purificação , Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/virologia , Coronavirus/genética , Coronavirus/isolamento & purificação , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , DNA Viral/isolamento & purificação , Doenças do Cão/epidemiologia , Cães , Fezes/virologia , Feminino , Itália/epidemiologia , Masculino , Infecções por Parvoviridae/epidemiologia , Infecções por Parvoviridae/virologia , Parvovirus/genética , Parvovirus/isolamento & purificação , Filogenia
6.
BMC Infect Dis ; 21(1): 9, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33407180

RESUMO

BACKGROUND: To determine the prevalence of enteric infections in Aboriginal children aged 0-2 years using conventional and molecular diagnostic techniques and to explore associations between the presence of pathogens and child growth. METHODS: Cross-sectional analysis of Aboriginal children (n = 62) residing in a remote community in Northern Australia, conducted from July 24th - October 30th 2017. Stool samples were analysed for organisms by microscopy (directly in the field and following fixation and storage in sodium-acetate formalin), and by qualitative PCR for viruses, bacteria and parasites and serology for Strongyloides-specific IgG. Child growth (height and weight) was measured and z scores calculated according to WHO growth standards. RESULTS: Nearly 60% of children had evidence for at least one enteric pathogen in their stool (37/62). The highest burden of infection was with adenovirus/sapovirus (22.9%), followed by astrovirus (9.8%) and Cryptosporidium hominis/parvum (8.2%). Non-pathogenic organisms were detected in 22.5% of children. Ten percent of children had diarrhea at the time of stool collection. Infection with two or more pathogens was negatively associated with height for age z scores (- 1.34, 95% CI - 2.61 to - 0.07), as was carriage of the non-pathogen Blastocystis hominis (- 2.05, 95% CI - 3.55 to - 0.54). CONCLUSIONS: Infants and toddlers living in this remote Northern Australian Aboriginal community had a high burden of enteric pathogens and non-pathogens. The association between carriage of pathogens/non-pathogens with impaired child growth in the critical first 1000 days of life has implications for healthy child growth and development and warrants further investigation. These findings have relevance for many other First Nations Communities that face many of the same challenges with regard to poverty, infections, and malnutrition.


Assuntos
Infecções por Adenovirus Humanos/epidemiologia , Adenovírus Humanos/genética , Infecções por Astroviridae/epidemiologia , Infecções por Caliciviridae/epidemiologia , Criptosporidiose/epidemiologia , Cryptosporidium/genética , Gastroenterite/epidemiologia , Mamastrovirus/genética , Sapovirus/genética , Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/isolamento & purificação , Animais , Infecções por Astroviridae/virologia , Austrália/epidemiologia , Infecções por Caliciviridae/virologia , Pré-Escolar , Estudos Transversais , Criptosporidiose/parasitologia , Cryptosporidium/isolamento & purificação , Diarreia/epidemiologia , Diarreia/parasitologia , Diarreia/virologia , Fezes/parasitologia , Fezes/virologia , Feminino , Gastroenterite/parasitologia , Gastroenterite/virologia , Humanos , Lactente , Recém-Nascido , Masculino , Mamastrovirus/isolamento & purificação , Grupo com Ancestrais Oceânicos , Reação em Cadeia da Polimerase/métodos , Prevalência , Sapovirus/isolamento & purificação
7.
BMC Infect Dis ; 21(1): 7, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33407198

RESUMO

BACKGROUND: Little is known about the etiology of childhood diarrhea in the United Arab Emirates (UAE) especially after the introduction of rotavirus vaccines. This study aimed to identify gastrointestinal pathogens in children with diarrhea (cases) and the carriage rate of these pathogens in asymptomatic children (controls). METHODS: Stool samples were collected from 203 cases and 73 controls who presented to two major hospitals in Al Ain city, UAE. Samples were analyzed with Allplex™ Gastrointestinal Full Panel Assay for common entero-pathogens. The association between diarrhea and the isolated pathogens was calculated in a multivariate logistic regression model. The adjusted attributable fractions (aAFs) were calculated for all pathogens significantly associated with cases. RESULTS: At least one pathogen was identified in 87 samples (42.8%) from cases and 17 (23.3%) from controls (P < 0.001). Rotavirus, norovirus GII and adenovirus were significantly more prevalent in cases. Their aAFs with 95% ci are 0.95 (0.64, 1.00) for rotavirus, 0.86 (0.38, 0.97) for norovirus GII and 0.84 (0.29, 0.96) for adenovirus. None of the 13 bacteria tested for were more commonly found in the cases than in controls. Cryptosporidium spp. were more significantly detected in cases than in controls. Co-infections occurred in 27.9% of the children. Viruses and parasites were significantly more likely to occur together only in the cases. CONCLUSIONS: Multiplex PCR revealed high positivity rates in both cases and controls which demand a cautious interpretation. Rotavirus remains the main childhood diarrhea pathogen in UAE. Effective strategies are needed to better control rotavirus and other causative pathogens.


Assuntos
Infecções por Adenovirus Humanos/epidemiologia , Adenovírus Humanos/genética , Infecções por Caliciviridae/epidemiologia , Coinfecção/epidemiologia , Criptosporidiose/epidemiologia , Cryptosporidium/genética , Diarreia/epidemiologia , Norovirus/genética , Infecções por Rotavirus/epidemiologia , Rotavirus/genética , Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/isolamento & purificação , Animais , Infecções por Caliciviridae/virologia , Estudos de Casos e Controles , Pré-Escolar , Coinfecção/parasitologia , Coinfecção/virologia , Criptosporidiose/parasitologia , Cryptosporidium/isolamento & purificação , Diarreia/parasitologia , Diarreia/virologia , Fezes/parasitologia , Fezes/virologia , Feminino , Humanos , Lactente , Masculino , Reação em Cadeia da Polimerase Multiplex/métodos , Norovirus/isolamento & purificação , Rotavirus/isolamento & purificação , Infecções por Rotavirus/virologia , Vacinas contra Rotavirus , Emirados Árabes Unidos/epidemiologia
8.
J Vet Sci ; 21(5): e71, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33016018

RESUMO

BACKGROUND: Feline calicivirus (FCV) is a major and highly infectious pathogen in cats worldwide. However, there have been limited studies about the status of FCV infections in Korea. OBJECTIVES: To investigate the current status of FCV infections in stray cats in Korea. METHODS: A novel reverse transcription polymerase chain reaction (RT-PCR) assay was developed based on the conserved nucleotide sequences of reported FCV strains. Field swab samples were collected from 122 cats (2 hospital admitted cats and 120 stray cats) in 2016 and 2017. All the samples were tested by virus isolation and 2 different RT-PCRs, including the novel RT-PCR, for the detection of FCV. RESULTS: The novel RT-PCR assay showed no cross-reactivity to the nucleic acids of the other feline pathogens tested, and the limit of detection was calculated as 10° TCID50/mL based on an in vitro assessment. The novel RT-PCR assay detected 5 positive samples from the 122 field samples, which showed perfect agreement with the results of the virus isolation method. In contrast, another RT-PCR assay used in a previous study in Korea detected no positive samples. The prevalence of FCV infection in stray cats was 2.5% (3/120) based on the results of virus isolation and the novel RT-PCR assays. CONCLUSIONS: The current study is the first report of the detection and prevalence of FCV in stray cats in Korea. The novel RT-PCR assay developed in this study showed high sensitivity and specificity, which indicates a useful diagnostic assay to identify FCV infection in cats.


Assuntos
Infecções por Caliciviridae/veterinária , Calicivirus Felino/isolamento & purificação , Doenças do Gato/epidemiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Animais , Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/virologia , Doenças do Gato/virologia , Gatos , Prevalência , República da Coreia/epidemiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Sensibilidade e Especificidade
9.
Sheng Wu Gong Cheng Xue Bao ; 36(8): 1536-1545, 2020 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-32924352

RESUMO

Moschus chrysogaster (sifanicus) viral hemorrhagic disease (McVHD) is an acute and highly lethal infectious disease caused by Moschus chrysogaster hemorrhagic disease virus (McHDV) whose genome sequence is highly homologous with rabbit hemorrhagic disease virus. To screen the protective antigen of McHDV and set the basis for study of McVHD vaccine, the antigen epitope of major structural protein VP60 of McHDV was analyzed, and the specific primers were designed to obtain three amplified DNA sequences encoding the main antigen epitope of VP60 from McHDV by using RT-PCR. Then the three DNA fragments were sequenced and cloned to prokaryotic expression vector with pET-28a(+) by using overlap extension PCR, and finally the prokaryotic expression plasmid pET-truncated-VP60 was constructed. Subsequently, the pET-truncated-VP60 was transformed into Escherichia coli BL21(DE3), and the recombinant proteins were expressed by IPTG induction. Finally, the expressed protein was purified and applied to immunize that without immunizing with RHD vaccine, then the antiserum titers were evaluated by the hemagglutination inhibition test, and the immune-protective efficacy of the recombinant proteins was observed and analyzed through animal challenge test. The results showed that the multi-epitope DNA fragments of VP60 of McHDV was successfully expressed in the form of inclusion bodies in E. coli, and the relative molecular weight of recombinant proteins is about 45 kDa. After immunized with the recombinant proteins, 100% of New Zealand white rabbits were resistant to attack of McHDV, which indicates efficient immune-protective efficacy of chosen epitope recombinant protein. The study laid a foundation for the development of the new subunit vaccines of McVHD.


Assuntos
Infecções por Caliciviridae , Expressão Gênica , Vírus da Doença Hemorrágica de Coelhos , Proteínas Estruturais Virais , Animais , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/virologia , Epitopos/genética , Escherichia coli/genética , Coelhos , Proteínas Estruturais Virais/genética , Proteínas Estruturais Virais/metabolismo
10.
Proc Natl Acad Sci U S A ; 117(38): 23782-23793, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32907944

RESUMO

Human noroviruses (HuNoVs) are the leading cause of viral gastroenteritis worldwide; yet currently, no vaccines or FDA-approved antiviral drugs are available to counter these pathogens. To understand HuNoV biology and the epithelial response to infection, we performed transcriptomic analyses, RT-qPCR, CRISPR-Cas9 modification of human intestinal enteroid (HIE) cultures, and functional studies with two virus strains (a pandemic GII.4 and a bile acid-dependent GII.3 strain). We identified a predominant type III interferon (IFN)-mediated innate response to HuNoV infection. Replication of both strains is sensitive to exogenous addition of IFNs, suggesting the potential of IFNs as therapeutics. To obtain insight into IFN pathway genes that play a role in the antiviral response to HuNoVs, we developed knockout (KO) HIE lines for IFN alpha and lambda receptors and the signaling molecules, MAVS, STAT1, and STAT2 An unexpected differential response of enhanced replication and virus spread was observed for GII.3, but not the globally dominant GII.4 HuNoV in STAT1-knockout HIEs compared to parental HIEs. These results indicate cellular IFN responses restrict GII.3 but not GII.4 replication. The strain-specific sensitivities of innate responses against HuNoV replication provide one explanation for why GII.4 infections are more widespread and highlight strain specificity as an important factor in HuNoV biology. Genetically modified HIEs for innate immune genes are useful tools for studying immune responses to viral or microbial pathogens.


Assuntos
Infecções por Caliciviridae , Interações Hospedeiro-Patógeno/imunologia , Interferons , Intestinos , Norovirus , Sistemas CRISPR-Cas , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/virologia , Humanos , Interferons/genética , Interferons/metabolismo , Intestinos/imunologia , Intestinos/virologia , Modelos Biológicos , Norovirus/genética , Norovirus/imunologia , Norovirus/patogenicidade , Organoides/imunologia , Organoides/virologia , Análise de Sequência de RNA , Transcriptoma/genética , Replicação Viral
11.
Arch Virol ; 165(11): 2605-2613, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32770483

RESUMO

Noroviruses are the main causative agents of acute viral gastroenteritis worldwide. However, no vaccine or specific antiviral treatment is available, imposing a heavy global health burden. The nucleoside analogue 2'-fluoro-2'-deoxycytidine (2'-FdC) has been reported to have broad antiviral activity. Here, we report that 2'-FdC significantly inhibits murine norovirus replication in macrophages. This effect was partially reversed by exogenous supplementation of cytidine triphosphate. The combination of 2'-FdC with mycophenolic acid, ribavirin or favipiravir (T705) exerts synergistic antiviral effects. These results indicate that 2'-FdC is a potential candidate for antiviral drug development against norovirus infection.


Assuntos
Antivirais/farmacologia , Desoxicitidina/análogos & derivados , Norovirus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Amidas/farmacologia , Animais , Infecções por Caliciviridae/tratamento farmacológico , Infecções por Caliciviridae/virologia , Linhagem Celular , Desoxicitidina/farmacologia , Humanos , Camundongos , Ácido Micofenólico/farmacologia , Norovirus/fisiologia , Pirazinas/farmacologia , Células RAW 264.7 , Ribavirina/farmacologia , Replicação Viral/fisiologia
12.
PLoS One ; 15(8): e0236754, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32756590

RESUMO

The antimalarial agent mefloquine is currently being investigated for its potential to inhibit feline coronavirus and feline calicivirus infections. A simple, high pressure liquid chromatography assay was developed to detect mefloquine plasma concentrations in feline plasma. The assay's lower limit of quantification was 250 ng/mL. The mean ± standard deviation intra- and inter-day precision expressed as coefficients of variation were 6.83 ± 1.75 and 5.33 ± 1.37%, respectively, whereas intra- and inter-day accuracy expressed as a percentage of the bias were 11.40 ± 3.73 and 10.59 ± 3.88%, respectively. Accordingly, this validated assay should prove valuable for future in vivo clinical trials of mefloquine as an antiviral agent against feline coronavirus and feline calicivirus. However, the proportion of mefloquine binding to feline plasma proteins has not been reported. The proportion of drug bound to plasma protein binding is an important concept when developing drug dosing regimens. As cats with feline infectious peritonitis (FIP) demonstrate altered concentrations of plasma proteins, the proportion of mefloquine binding to plasma proteins in both clinically normal cats and FIP-affected cats was also investigated. An in vitro method using rapid equilibrium dialysis demonstrated that mefloquine was highly plasma protein bound in both populations (on average > 99%).


Assuntos
Calicivirus Felino/efeitos dos fármacos , Coronavirus Felino/efeitos dos fármacos , Peritonite Infecciosa Felina/tratamento farmacológico , Mefloquina/farmacologia , Animais , Proteínas Sanguíneas/genética , Infecções por Caliciviridae/tratamento farmacológico , Infecções por Caliciviridae/veterinária , Infecções por Caliciviridae/virologia , Calicivirus Felino/patogenicidade , Gatos , Coronavirus Felino/patogenicidade , Peritonite Infecciosa Felina/sangue , Peritonite Infecciosa Felina/virologia , Ligação Proteica/efeitos dos fármacos
13.
Arch Virol ; 165(10): 2335-2340, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32719956

RESUMO

Sapoviruses are increasingly being recognized as pathogens associated with gastroenteritis in humans. Human sapoviruses are currently assigned to 18 genotypes (GI.1-7, GII.1-8, GIV.1, and GV.1-2) based on the sequence of the region encoding the major structural protein. In this study, we evaluated 11 polymerase chain reaction (PCR) assays using published and newly designed/modified primers and showed that four PCR assays with different primer combinations amplified all of the tested human sapovirus genotypes using either synthetic DNA or cDNA prepared from human sapovirus-positive fecal specimens. These assays can be used as improved broadly reactive screening tests or as tools for molecular characterization of human sapoviruses.


Assuntos
Infecções por Caliciviridae/virologia , Primers do DNA/química , Gastroenterite/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Sapovirus/genética , Proteínas Estruturais Virais/genética , Sequência de Bases , Infecções por Caliciviridae/diagnóstico , Primers do DNA/genética , Fezes/virologia , Gastroenterite/diagnóstico , Expressão Gênica , Genótipo , Humanos , Tipagem Molecular/métodos , Filogenia , Sapovirus/classificação , Sapovirus/isolamento & purificação , Alinhamento de Sequência
14.
Int J Food Microbiol ; 333: 108787, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-32702583

RESUMO

Human noroviruses (HuNoVs) are the primary non-bacterial pathogens causing acute gastroenteritis worldwide. Here we reported a co-infection of HuNoVs with different genotypes during an outbreak of gastroenteritis in travelers. The aim was to trace the source and transmission patterns of the infections using next-generation sequencing (NGS). An investigation was conducted on a cross-border travel group who came back to China from Thailand for symptoms of gastroenteritis. Anal swabs were collected from 23 people and samples were analyzed using RT-qPCR. A total of 11 samples tested positive for HuNoVs. All samples tested negative for bacterial pathogens in the surveillance list. Positive samples for HuNoVs were further analyzed using NGS. Seven out of 11 positive samples were sequenced and 16 viral genome sequences for 10 different strains of HuNoVs were obtained. We demonstrated that the outbreak was associated with co-infection of multiple genotypes of HuNoVs and the source of infections was probably contaminated water or food. Besides, four different HuNoVs genotypes (GI.5[P12], GIX.1[GII·P15], GI.7[P7] and GII.8[P8]) were identified in one patient. Co-infection with both genogroup GI and GII, and co-infection with two different P types ([P10] and [P13]) of genotype GI.3 were identified in different patients. Findings from this study show that individuals can be simultaneously infected with multiple strains of HuNoVs and NGS can help investigating these issues. Further, this study shows that food and water are potential vehicles for transmission of multiple foodborne viruses.


Assuntos
Infecções por Caliciviridae/diagnóstico , Doenças Transmitidas por Alimentos/virologia , Gastroenterite/diagnóstico , Norovirus/genética , Norovirus/isolamento & purificação , Adolescente , Adulto , Sequência de Bases , Infecções por Caliciviridae/virologia , Criança , China/epidemiologia , Surtos de Doenças , Feminino , Gastroenterite/virologia , Genoma Viral/genética , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Metagenômica , Pessoa de Meia-Idade , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Tailândia , Viagem , Adulto Jovem
15.
PLoS One ; 15(7): e0236502, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32702014

RESUMO

The transmission of human norovirus excreted from infected persons occasionally causes sporadic infections and outbreaks. Both symptomatic patients and asymptomatic carriers have been reported to contribute to norovirus transmission, but little is known about the magnitude of the contribution of asymptomatic carriers. We carried out a 1-year survey of residents of a district of Bangkok, Thailand to determine the percentage of norovirus transmissions originating from asymptomatic individuals. We screened 38 individuals recruited from 16 families from May 2018 to April 2019 for GI and GII genotypes. Norovirus was detected every month, and 101 of 716 stool samples (14.1%) from individuals with no symptoms of acute gastroenteritis were norovirus-positive. The average infection frequency was 2.4 times per person per year. Fourteen genotypes were identified from the positive samples, with GII.4 being detected most frequently. Notably, 89.1% of the norovirus-positive samples were provided by individuals with no diarrhea episode. Similar to cases of symptomatic infections in Thailand, asymptomatic infections were observed most frequently in December. We detected 4 cases of NV infection caused by household transmission, and 3 of the 4 transmissions originated from asymptomatic individuals. We also identified a case in which norovirus derived from an asymptomatic individual caused diarrhea in a family member. These results suggest that asymptomatic individuals play a substantial role in both the maintenance and spreading of norovirus in a community through household transmission.


Assuntos
Infecções Assintomáticas/epidemiologia , Infecções por Caliciviridae/transmissão , Gastroenterite/virologia , Norovirus/patogenicidade , Adolescente , Adulto , Idoso , Infecções por Caliciviridae/patologia , Infecções por Caliciviridae/virologia , Criança , Diarreia/patologia , Diarreia/virologia , Surtos de Doenças , Fezes/virologia , Feminino , Gastroenterite/patologia , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , RNA Viral/genética , RNA Viral/isolamento & purificação , Adulto Jovem
16.
J Virol ; 94(17)2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32581099

RESUMO

Human norovirus is the leading cause of gastroenteritis worldwide, yet basic questions about its life cycle remain unanswered due to an historical lack of robust experimental systems. Recent studies on the closely related murine norovirus (MNV) have identified CD300LF as an indispensable entry factor for MNV. We compared the MNV susceptibilities of cells from different mouse strains and identified polymorphisms in murine CD300LF which are critical for its function as an MNV receptor. Bone marrow-derived macrophages (BMDMs) from I/LnJ mice were resistant to infection from multiple MNV strains which readily infect BMDMs from C57BL/6J mice. The resistance of I/LnJ BMDMs was specific to MNV, since the cells supported infection of other viruses comparably to C57BL/6J BMDMs. Transduction of I/LnJ BMDMs with C57BL/6J CD300LF made the cells permissible to MNV infection, suggesting that the cause of resistance lies in the entry step of MNV infection. In fact, we mapped this phenotype to a 4-amino-acid difference at the CC' loop of CD300LF; swapping of these amino acids between C57BL/6J and I/LnJ CD300LF proteins made the mutant C57BL/6J CD300LF functionally impaired and the corresponding mutant of I/LnJ CD300LF functional as an MNV entry factor. Surprisingly, expression of the I/LnJ CD300LF in other cell types made the cells infectible by MNV, even though the I/LnJ allele did not function as an MNV receptor in macrophage-like cells. Correspondingly, I/LnJ CD300LF bound MNV virions in permissive cells but not in nonpermissive cells. Collectively, our data suggest the existence of a cell type-specific modifier of MNV entry.IMPORTANCE MNV is a prevalent model system for studying human norovirus, which is the leading cause of gastroenteritis worldwide and thus a sizeable public health burden. Elucidating mechanisms underlying susceptibility of host cells to MNV infection can lead to insights on the roles that specific cell types play during norovirus pathogenesis. Here, we show that different alleles of the proteinaceous receptor for MNV, CD300LF, function in a cell type-dependent manner. In contrast to the C57BL/6J allele, which functions as an MNV entry factor in all tested cell types, including human cells, I/LnJ CD300LF does not function as an MNV entry factor in macrophage-like cells but does allow MNV entry in other cell types. Together, these observations indicate the existence of cell type-specific modifiers of CD300LF-dependent MNV entry.


Assuntos
Infecções por Caliciviridae/virologia , Resistência à Doença/genética , Polimorfismo Genético , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo , Receptores Virais/genética , Receptores Virais/metabolismo , Animais , Sítios de Ligação , Gastroenterite/virologia , Macrófagos/virologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Modelos Moleculares , Norovirus , Conformação Proteica , Receptores Imunológicos/química , Análise de Sequência de Proteína , Internalização do Vírus
17.
Arch Virol ; 165(7): 1647-1652, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32356188

RESUMO

On 31 March 2019, 68 school students suffered from vomiting, diarrhea, and abdominal pain after participating in a group activity at a commercial park. In this outbreak, multiple norovirus genotypes were observed, including GII.2[P16], GII.17[P17], and GII.13[P21]. Further, we determined the full-genome sequences of two strains of GII.13[P21] recombinant noroviruses, which were 7434 nt long. Phylogenetic analysis based on open reading frames (ORFs) 1 and 2 revealed that these recombinants were related to stains of different genotypes from different countries. The full genome nucleotide sequences of the two isolates were 97.0% and 98.0% identical to those of strains from London and Thailand, respectively. Simplot analysis revealed the presence of a break point at nt 5059 in the ORF1 region. The histo-blood group antigen binding sites were conserved in both recombinant viruses. Our findings not only provide valuable genetic information about a recombinant norovirus but also contribute to our general understanding of the evolution, genetic diversity, and distribution of noroviruses.


Assuntos
Infecções por Caliciviridae/virologia , Genoma Viral , Norovirus/genética , Sequência de Bases , Infecções por Caliciviridae/epidemiologia , Criança , China/epidemiologia , Surtos de Doenças , Feminino , Gastroenterite/epidemiologia , Gastroenterite/virologia , Genótipo , Humanos , Masculino , Norovirus/classificação , Norovirus/isolamento & purificação , Fases de Leitura Aberta , Filogenia
18.
Virology ; 546: 109-121, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32452409

RESUMO

The inflammasome machinery has recently been recognized as an emerging pillar of innate immunity. However, little is known regarding the interaction between the classical interferon (IFN) response and inflammasome activation in response to norovirus infection. We found that murine norovirus (MNV-1) infection induces the transcription of IL-1ß, a hallmark of inflammasome activation, which is further increased by inhibition of IFN response, but fails to trigger the release of mature IL-1ß. Interestingly, pharmacological inflammasome inhibitors do not affect viral replication, but slightly reverse the inflammasome activator lipopolysaccharide (LPS)-mediated inhibition of MNV replication. LPS efficiently stimulates the transcription of IFN-ß through NF-ĸB, which requires the transcription factors IRF3 and IRF7. This activates downstream antiviral IFN-stimulated genes (ISGs) via the JAK-STAT pathway. Moreover, inhibition of NF-ĸB and JAK-STAT signaling partially reverse LPS-mediated anti-MNV activity, suggesting additional antiviral mechanisms activated by NF-ĸB. This study reveals additional insight in host defense against MNV infection.


Assuntos
Antivirais/farmacologia , Infecções por Caliciviridae/imunologia , Janus Quinases/imunologia , Lipopolissacarídeos/farmacologia , Macrófagos/imunologia , NF-kappa B/imunologia , Norovirus/efeitos dos fármacos , Fatores de Transcrição STAT/imunologia , Animais , Infecções por Caliciviridae/genética , Infecções por Caliciviridae/virologia , Humanos , Inflamassomos/genética , Inflamassomos/imunologia , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/imunologia , Janus Quinases/genética , Macrófagos/virologia , Camundongos , NF-kappa B/genética , Norovirus/genética , Norovirus/fisiologia , Fatores de Transcrição STAT/genética , Transdução de Sinais/efeitos dos fármacos
19.
J Gen Virol ; 101(5): 510-522, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32242791

RESUMO

Noroviruses are recognized as the major cause of non-bacterial gastroenteritis in humans. Molecular mechanisms driving norovirus evolution are the accumulation of point mutations and recombination. Recombination can create considerable changes in a viral genome, potentially eliciting a fitness cost, which must be compensated via the adaptive capacity of a recombinant virus. We previously described replicative fitness reduction of the first in vitro generated WU20-CW1 recombinant murine norovirus, RecMNV. In this follow-up study, RecMNV's capability of replicative fitness recuperation and genetic characteristics of RecMNV progenies at early and late stages of an adaptation experiment were evaluated. Replicative fitness regain of the recombinant was demonstrated via growth kinetics and plaque size differences between viral progenies prior to and post serial in vitro passaging. Point mutations at consensus and sub-consensus population levels of early and late viral progenies were characterized via next-generation sequencing and putatively associated to fitness changes. To investigate the effect of genomic changes separately and in combination in the context of a lab-generated inter-MNV infectious virus, mutations were introduced into a recombinant WU20-CW1 cDNA for subsequent DNA-based reverse genetics recovery. We thus associated fitness loss of RecMNV to a C7245T mutation and functional VP2 (ORF3) truncation and demonstrated individual and cumulative compensatory effects of one synonymous OFR2 and two non-synonymous ORF1 consensus-level mutations acquired during successive rounds of in vitro replication. Our data provide evidence of viral adaptation in a controlled environment via genetic drift after genetic shift induced a fitness cost of an infectious recombinant norovirus.


Assuntos
Norovirus/genética , Replicação Viral/genética , Animais , Infecções por Caliciviridae/virologia , Linhagem Celular , DNA Complementar/genética , Seguimentos , Deriva Genética , Genoma Viral/genética , Camundongos , Mutação Puntual/genética , Células RAW 264.7 , RNA Viral/genética
20.
PLoS Pathog ; 16(4): e1008242, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32251490

RESUMO

Murine norovirus (MNoV) is an important model of human norovirus (HNoV) and mucosal virus infection more broadly. Viral receptor utilization is a major determinant of cell tropism, host range, and pathogenesis. The bona fide receptor for HNoV is unknown. Recently, we identified CD300lf as a proteinaceous receptor for MNoV. Interestingly, its paralogue CD300ld was also sufficient for MNoV infection in vitro. Here we explored whether CD300lf is the sole physiologic receptor in vivo and whether HNoV can use a CD300 ortholog as an entry receptor. We report that both CD300ld and CD300lf are sufficient for infection by diverse MNoV strains in vitro. We further demonstrate that CD300lf is essential for both oral and parenteral MNoV infection and to elicit anti-MNoV humoral responses in vivo. In mice deficient in STAT1 signaling, CD300lf is required for MNoV-induced lethality. Finally, we demonstrate that human CD300lf (huCD300lf) is not essential for HNoV infection, nor does huCD300lf inhibit binding of HNoV virus-like particles to glycans. Thus, we report huCD300lf is not a receptor for HNoV.


Assuntos
Infecções por Caliciviridae/virologia , Especificidade de Hospedeiro , Interações Hospedeiro-Patógeno , Norovirus/metabolismo , Receptores Imunológicos/metabolismo , Receptores Virais/metabolismo , Animais , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Norovirus/crescimento & desenvolvimento , Receptores Imunológicos/fisiologia , Tropismo Viral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...