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1.
Front Cell Infect Microbiol ; 11: 695134, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34368015

RESUMO

The objective of this study was to evaluate the value of molecular methods in the management of community-acquired pneumonia (CAP) in children. Previously developed mass spectrometry (MS)-based methods combined with quantitative real-time PCR (combined-MS methods) were used to describe the aetiology and evaluate antibiotic therapy in the enrolled children. Sputum collected from 302 children hospitalized with CAP were analyzed using the combined-MS methods, which can detect 19 viruses and 12 bacteria related to CAP. Based on the results, appropriate antibiotics were determined using national guidelines and compared with the initial empirical therapies. Respiratory pathogens were identified in 84.4% of the patients (255/302). Co-infection was the predominant infection pattern (51.7%, 156/302) and was primarily a bacterial-viral mixed infection (36.8%, 111/302). Compared with that using culture-based methods, the identification rate for bacteria using the combined-MS methods (61.8%, 126/204) increased by 28.5% (p <0.001). Based on the results of the combined-MS methods, the initial antibiotic treatment of 235 patients was not optimal, which mostly required switching to ß-lactam/ß-lactamase inhibitor combinations or reducing unnecessary macrolide treatments. Moreover, using the combined-MS methods to guide antibiotic therapy showed potential to decrease the length of stay in children with severe CAP. For children with CAP, quantitative molecular testing on sputum can serve as an important complement to traditional culture methods. Early aetiology elucidated using molecular testing can help guide the antibiotic therapy.


Assuntos
Infecções Comunitárias Adquiridas , Pneumonia , Antibacterianos/uso terapêutico , Bactérias/genética , Criança , Infecções Comunitárias Adquiridas/tratamento farmacológico , Humanos , Espectrometria de Massas , Pneumonia/tratamento farmacológico
2.
Virol Sin ; 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34398429

RESUMO

Human respiratory syncytial virus (RSV) is a major pathogen of acute lower respiratory tract infection among young children. To investigate the prevalence and genetic characteristics of RSV in China, we performed a molecular epidemiological study during 2015-2019. A total of 964 RSV-positive specimens were identified from 5529 enrolled patients during a multi-center study. RSV subgroup A (RSV-A) was the predominant subgroup during this research period except in 2016. Totally, 535 sequences of the second hypervariable region (HVR-2) of the G gene were obtained. Combined with 182 Chinese sequences from GenBank, phylogenetic trees showed that 521 RSV-A sequences fell in genotypes ON1 (512), NA1 (6) and GA5 (3), respectively; while 196 RSV-B sequences fell in BA9 (193) and SAB4 (3). ON1 and BA9 were the only genotypes after December 2015. Genotypes ON1 and BA9 can be separated into 10 and 7 lineages, respectively. The HVR-2 of genotype ON1 had six amino acid changes with a frequency more than 10%, while two substitutions H258Q and H266L were co-occurrences. The HVR-2 of genotype BA9 had nine amino acid substitutions with a frequency more than 10%, while the sequences with T290I and T312I were all from 2018 to 2019. One N-glycosylation site at 237 was identified among ON1 sequences, while two N-glycosylation sites (296 and 310) were identified in the 60-nucleotide duplication region of BA9. To conclusion, ON1 and BA9 were the predominant genotypes in China during 2015-2019. For the genotypes ON1 and BA9, the G gene exhibited relatively high diversity and evolved continuously.

3.
Front Microbiol ; 12: 688661, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34267738

RESUMO

Human adenoviruses (HAdVs) are important pathogens causing respiratory infections; 3.5-11% of childhood community-acquired pneumonia is associated with HAdV infection. Human adenovirus type 3 (HAdV-3), leading to severe morbidity and mortality, is one of the most prevalent genotype among adenoviruses responsible for acute respiratory infections (ARIs) in children in China. To identify the genetic variation of HAdV-3 in children with ARIs in China, a molecular epidemiological study was conducted. A total of 54 HAdV-3 isolated strains were obtained from children with ARIs in Beijing, Wenzhou, Shanghai, Shijiazhuang, Hangzhou, Guangzhou, and Changchun from 2014 to 2018. Thirty-two strains of which were selected for whole-genome sequencing, while the hexon, penton base, and fiber genes were sequenced for remaining strains. Bioinformatics analysis was performed on the obtained sequences. The phylogenetic analyses based on whole-genome sequences, major capsid protein genes (hexon, penton base, and fiber), and early genes (E1, E2, E3, and E4) showed that the HAdV-3 strains obtained in this study always clustered together with the reference strains from Chinese mainland, while the HAdV-3 prototype strain formed a cluster independently. Compared with the prototype strain, all strains possessed nine amino acid (AA) substitutions at neutralization antigenic epitopes of hexon. The homology models of the hexon protein of the HAdV-3 prototype and strain BJ20160214 showed that there was no evident structural change at the AA mutation sites. Two AA substitutions were found at the Arg-Gly-Asp (RGD) loop and hypervariable region 1 (HVR1) region of the penton base. A distinct AA insertion (20P) in the highly conserved PPPSY motif of the penton base that had never been reported before was observed. Recombination analysis indicated that partial regions of protein IIIa precursor, penton base, and protein VII precursor genes among all HAdV-3 strains in this study were from HAdV-7. This study showed that the genomes of the HAdV-3 strains in China were highly homologous. Some AA mutations were found at antigenic sites; however, the significance needs further study. Our data demonstrated the molecular characteristics of HAdV-3 circulating in China and was highly beneficial for further epidemiological exploration and the development of vaccines and drugs against HAdV-3.

4.
Virol Sin ; 36(3): 382-392, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33400092

RESUMO

To investigate the molecular epidemiology and genetic variation of human adenovirus type 7 (HAdV-7) in children with acute respiratory infections (ARI) in China. HAdV-7-positive respiratory samples collected from children with ARI in Beijing, Shijiazhuang, Wenzhou and Guangzhou from 2014-2018 were selected for gene amplification and sequence analysis. Fifty-seven HAdV-7 clinical strains with hexon, penton base and fiber gene sequences were obtained. Meanwhile 17 strains were selected randomly from different cities for whole genome sequencing. Phylogenetic and variation analyses were performed based on the obtained sequences, HAdV-7 prototype strain Gomen (AY594255), vaccine strains (AY495969 and AY594256) and representative sequences of strains. The phylogenetic trees constructed based on whole genome sequences, major capsid protein genes (hexon, penton base and fiber) and the early genes (E1, E2, E3 and E4) were not completely consistent. The HAdV-7 strains obtained in this study always clustered with most of the circulating strains worldwide from the 1980s to the present. Compared with the HAdV-7 prototype strain Gomen (AY594255), some amino acid mutations in loop1 and loop2 of hexon and the RGD loop region of the penton base gene were observed. Recombination analysis showed that partial regions of 55 kDa protein and 100 kDa hexon-assembly associated protein genes among all HAdV-7 strains in this study were from HAdV-16 and HAdV-3, respectively. Our study demonstrated the molecular evolution characteristics of HAdV-7 strains circulating in China and provided basic reference data for the prevention, control and vaccine development of HAdV-7.


Assuntos
Infecções por Adenovirus Humanos , Adenovírus Humanos , Infecções por Adenovirus Humanos/epidemiologia , Adenovírus Humanos/genética , Criança , China/epidemiologia , Evolução Molecular , Genoma Viral , Humanos , Filogenia , Análise de Sequência de DNA
5.
Pediatr Investig ; 4(4): 236-241, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33376950

RESUMO

Importance: In this study, we retrospectively investigated the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies within serum samples from children in Beijing, China. These findings provide preliminary guidance regarding population susceptibility to SARS-CoV-2, which will aid in establishing policy toward coronavirus disease 2019 (COVID-19) prevention and control. Objective: To understand the seropositivity of anti-SARS-CoV-2 IgM/IgG antibodies among children in Beijing, China, evaluate the susceptibility of children in Beijing to SARS-CoV-2, and provide prima facie evidence to guide SARS-CoV-2 prevention and control. Methods: IgM/IgG antibody kits (colloidal gold) were used to conduct preliminary screening of SARS-CoV-2 IgM/IgG antibodies in serum samples of children who presented to Beijing Children's Hospital, Capital Medical University, having fever or requiring hospitalization, from March 2020 to August 2020. Statistical analysis of anti-SARS-CoV-2 antibody seropositivity was performed according to the children's general demographic characteristics, timing of admission to hospital, presence of pneumonia, and viral nucleic acid test results. Results: The study included 19 797 children with both IgM and IgG antibody results. Twenty-four children had anti-SARS-CoV-2 IgM-positive results (positive rate of 1.2‰), twelve children had anti-SARS-CoV-2 IgG-positive results (positive rate of 0.6‰). Viral nucleic acid test results were negative for the above-mentioned children with positive antibody findings; during the study, two children exhibited positive viral nucleic acid test results, but their anti-SARS-CoV-2 IgM/IgG antibody results were negative. Anti-SARS-CoV-2 IgM antibody seropositivity was higher in the <1-year-old group than in the ≥6-year-old group. The rates of anti-SARS-CoV-2 IgM seropositivity was highest in August from March to August; IgG results did not significantly differ over time. The rates of anti-SARS-CoV-2 IgM or IgG seropositivity among children with and without suspected pneumonia did not significantly differ between groups. Interpretation: During the study period, the rates of anti-SARS-CoV-2 IgM/IgG antibody seropositivity were low among children who presented to Beijing Children's Hospital, Capital Medical University. The findings suggest that children in Beijing are generally susceptible to SARS-CoV-2 infection; COVID-19 prevention and control measures should be strengthened to prevent disease in children.

6.
BMC Infect Dis ; 20(1): 387, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-32473625

RESUMO

BACKGROUND: To compare the clinical characteristics of acute lower respiratory tract infections (ALRTIs) caused by respiratory syncytial virus (RSV) and human rhinovirus (HRV) and to explore the relationship between the development of recurrent wheezing/asthma and RSV/ HRV infections in infancy. METHODS: Retrospective study was conducted to compare the clinical characteristics of acute lower respiratory tract infections (ALRTIs). Hospitalized patients with ALRTIs from March 2007 to December 2016 were screened. Single RSV cases (s-RSV), single HRV cases (s-HRV), and cases who had co-infection with the two viruses were enrolled. Follow-up was performed to determine whether either specific respiratory virus infection was related to subsequent development of recurrent wheezing/asthma. RESULTS: The s-RSV children were the youngest (P = 0.021), they experienced the most serious condition (P < 0.001) and respiratory failure (P < 0.001), they also required highest demand of oxygen therapy (P < 0.001). And in s-RSV group, the incidence of development of recurrent wheezing was significantly higher in subgroup with the family history of wheezing than that without (P < 0.001). CONCLUSION: The s-RSV cases suffered from the worst severity of illness, respiratory failure and required highest demand of oxygen therapy. Recurrent wheezing was more common in s-RSV group with family history of wheezing than those without.


Assuntos
Asma/epidemiologia , Infecções por Picornaviridae/complicações , Infecções por Vírus Respiratório Sincicial/complicações , Infecções Respiratórias/complicações , Asma/etiologia , Criança , Pré-Escolar , Coinfecção/epidemiologia , Feminino , Humanos , Incidência , Lactente , Masculino , Infecções por Picornaviridae/epidemiologia , Sons Respiratórios/etiologia , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Estudos Retrospectivos
7.
Arch Virol ; 164(12): 2975-2984, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31570994

RESUMO

Coxsackievirus A16 (CV-A16) is one of the main causative agents of hand, foot and mouth disease (HFMD) in young children and has become prevalent in the Asia-Pacific region in recent years. However, no approved vaccines or drugs are available for CV-A16 infection. CV-A16 virus-like particles (VLPs) are a potential vaccine candidate; however, whether the intranasal route of immunization is suitable for inducing immune responses against CV-A16 infection has not been clarified. In this study, the comprehensive immunogenicity and protective efficacy of the CV-A16 VLP vaccine were evaluated by multiple methods in a mouse model. In mice, a high neutralizing antibody (NTAb) titre could be elicited by intranasal immunization with CV-A16 VLPs, which produced NTAb levels similar to those induced by intranasal immunization with inactivated CV-A16. Passive immunity with NTAbs provided very good protection, as the survival rate of the immunized neonatal mice was 100% after challenges with CV-A16 at a dose of 1000 LD50. Passive protective effects were transferred to the neonates via the mother, thus protecting all the pups against challenges with the homologous or heterologous strains of CV-A16 at a dose of 1000 LD50. In addition, intranasal immunization with CV-A16 VLPs also induced the production of mucosal secretory IgA (s-IgA) antibodies, which may inhibit CV-A16 virus invasion. This study provides valuable supplemental information to facilitate our understanding of the specific protective efficacy of CV-A16 VLPs and has significance for development of the candidate vaccine into a safe and effective vaccine.


Assuntos
Enterovirus Humano A/imunologia , Infecções por Enterovirus/prevenção & controle , Nariz/virologia , Vacinas Virais/administração & dosagem , Animais , Animais Recém-Nascidos , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Enterovirus Humano A/genética , Infecções por Enterovirus/imunologia , Infecções por Enterovirus/virologia , Feminino , Humanos , Imunização , Camundongos , Camundongos Endogâmicos ICR , Vacinas Virais/genética , Vacinas Virais/imunologia
8.
Cell ; 177(6): 1553-1565.e16, 2019 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-31104841

RESUMO

Enterovirus B (EV-B), a major proportion of the genus Enterovirus in the family Picornaviridae, is the causative agent of severe human infectious diseases. Although cellular receptors for coxsackievirus B in EV-B have been identified, receptors mediating virus entry, especially the uncoating process of echovirus and other EV-B remain obscure. Here, we found that human neonatal Fc receptor (FcRn) is the uncoating receptor for major EV-B. FcRn binds to the virus particles in the "canyon" through its FCGRT subunit. By obtaining multiple cryo-electron microscopy structures at different stages of virus entry at atomic or near-atomic resolution, we deciphered the underlying mechanisms of enterovirus attachment and uncoating. These structures revealed that different from the attachment receptor CD55, binding of FcRn to the virions induces efficient release of "pocket factor" under acidic conditions and initiates the conformational changes in viral particle, providing a structural basis for understanding the mechanisms of enterovirus entry.


Assuntos
Enterovirus Humano B/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Antígenos de Histocompatibilidade Classe I/ultraestrutura , Receptores Fc/metabolismo , Receptores Fc/ultraestrutura , Capsídeo/metabolismo , Microscopia Crioeletrônica , Enterovirus , Enterovirus Humano B/patogenicidade , Infecções por Enterovirus/metabolismo , Antígenos de Histocompatibilidade Classe I/fisiologia , Humanos , Modelos Moleculares , Filogenia , Receptores Fc/fisiologia , Vírion , Internalização do Vírus
9.
Virol Sin ; 34(1): 50-58, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30790201

RESUMO

Echovirus 18 (E18), a serotype of Enterovirus B (EV-B) species, is an important pathogen in aseptic meningitis. E18 had rarely been detected in mainland China, but became the predominant pathogen associated with viral encephalitis (VE) and meningitis in Hebei province for the first time in 2015. To investigate the molecular epidemiology and genetic characteristics of E18 in mainland China, sixteen E18 strains from patient throat swabs with hand, foot, and mouth disease (HFMD) in six provinces in China collected between 2015 and 2016, and four E18 strains isolated from 18 patient cerebrospinal fluid specimens with VE in Hebei Province in 2015 were obtained and sequenced. Combined with the sequences from the GenBank database, we performed an extensive genetic analysis. Phylogenetic analysis of VP1 gene sequences revealed that all E18 strains from mainland China after 2015 belonged to subgenotype C2. There were no obvious specific differences in phylogenetic and variation analyses of E18 genome sequences between HFMD and VE/meningitis strains. Potential multiple recombination may have occurred in the 5'-untranslated region and in the P2 and P3 nonstructural protein-encoding regions of E18 strains from China. The current E18 strains were potential multiple-recombinant viruses. Overall, these findings supported that E18 caused HFMD, VE, and meningitis, although there were no significant associations between clinical features and viral genomic characteristics.


Assuntos
Enterovirus Humano B/genética , Infecções por Enterovirus/epidemiologia , Genoma Viral , Genótipo , Proteínas do Capsídeo/genética , China/epidemiologia , Surtos de Doenças , Encefalite Viral/epidemiologia , Enterovirus Humano B/patogenicidade , Infecções por Enterovirus/virologia , Doença de Mão, Pé e Boca/epidemiologia , Humanos , Meningite Viral/epidemiologia , Filogenia , RNA Viral/genética , Recombinação Genética
11.
Sci Rep ; 8(1): 4491, 2018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29540836

RESUMO

To identify the variations in fusion (F) protein gene of RSV in China, a molecular epidemiological study was conducted. A total of 553 RSV positive specimens were collected from 2338 pediatric patients hospitalized with community-acquired pneumonia during a multi-center study conducted during 2014-2016. A total of 252 samples (183 RSV A, 69 RSV B) were selected for F gene sequencing, and analyzed together with 142 F gene sequences downloaded from GenBank. The result showed that all the Chinese RSV A and RSV B strains could be divided respectively into three branches. Compared with RSV A/B prototype sequences respectively, there were significant amino acid (AA) mutations at multiple antigenic sites. For RSV A, changes were found at AA residues 122, 124, 125, 276 and 384, and for RSV B at AA residues 45, 116, 125, 172, 173 and 202. Variations in human histocompatibility leukocyte antigen-restricted CTL epitopes were also observed. In total, 56 amino acid differences for the complete F protein were found between the RSV A and B groups in China, while several mutations were only found in the RSV B strains during 2015-2016. The RSV F gene is relatively conserved in China, however, limited mutations are still occurring with time.


Assuntos
Infecções Comunitárias Adquiridas/virologia , Variação Genética , Pneumonia Viral/virologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Proteínas Virais de Fusão/genética , Alelos , Criança , Pré-Escolar , China/epidemiologia , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/imunologia , Epitopos de Linfócito T/imunologia , Feminino , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Filogenia , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Infecções por Vírus Respiratório Sincicial/imunologia , Vírus Sincicial Respiratório Humano/imunologia , Vírus Sincicial Respiratório Humano/isolamento & purificação , Análise de Sequência de DNA , Linfócitos T Citotóxicos/imunologia , Proteínas Virais de Fusão/imunologia
12.
Pediatr Investig ; 2(2): 98-104, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32851241

RESUMO

Importance: Viral encephalitis and meningitis are severe infectious diseases responsible for substantial morbidity and mortality in children. Enteroviruses are typically the most common causative agents of viral encephalitis and meningitis. Objective: This study aimed to investigate the etiology of viral encephalitis and meningitis among children in Hebei province, China. Methods: Cerebrospinal fluid samples from children with viral encephalitis (n=309) and meningitis (n=133) were collected between Nov 2013 and Dec 2015 and viral pathogens were identified by real-time and multiplex PCR. Amplification and sequencing of partial VP1 genes was used to type enteroviruses. Results: The causative pathogen was successfully detected in 176 (57%) patients with viral encephalitis and 82 (61.7%) patients with viral meningitis. The most common causative agents of both viral encephalitis and meningitis were enteroviruses (55.7% and 64.6% of cases, respectively). The most common enterovirus serotypes identified were echovirus 18, echovirus 6 and echovirus 30. Echovirus 18 accounted for 74.4% of all typed enteroviruses and caused a viral encephalitis and meningitis outbreak in Hebei province in 2015. By contrast, the major enterovirus serotypes circulating in 2014 were echovirus 6 and echovirus 30. Interpretation: Enteroviruses were the main causative agents of viral encephalitis and meningitis in children in Hebei province from Nov 2013 to Dec 2015. Echovirus 18 became the leading cause of viral encephalitis and meningitis for the first time in Hebei province in 2015.

13.
Arch Virol ; 162(12): 3769-3778, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28913577

RESUMO

Central nervous system infection (CNSI) results in significant health and economic burdens worldwide, but the diversity of causative pathogens makes differential diagnosis very difficult. Although PCR and real-time fluorescent quantitative PCR (q-PCR) assays are widely applied for pathogen detection, they are generally optimized for the detection of a single or limited number of targets and are not suitable for the diagnosis of numerous CNSI agents. In this study, we describe the development of a resequencing pathogen microarray (RPM-IVDC4) method for the simultaneous detection of viruses, bacteria, fungi and parasites that cause CNSI. The test panel of this assay included more than 100 microorganism species across 45 genera and 30 families. The analytical specificity and sensitivity were examined using a panel of positive reference strains, and the clinical performance was evaluated using 432 clinical samples by comparing the results with q-PCR assays. Our results demonstrated good performance of the RPM-IVDC4 assay in terms of sensitivity, specificity and detection range, suggesting that the platform can be further developed for high-throughput CNSI diagnosis.


Assuntos
Infecções do Sistema Nervoso Central/diagnóstico , Infecções do Sistema Nervoso Central/etiologia , Análise em Microsséries/métodos , Técnicas de Diagnóstico Molecular/métodos , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/microbiologia , Diagnóstico Diferencial , Ensaios de Triagem em Larga Escala , Humanos , Micoses/diagnóstico , Micoses/microbiologia , Doenças Parasitárias/diagnóstico , Doenças Parasitárias/parasitologia , Sensibilidade e Especificidade , Viroses/diagnóstico , Viroses/virologia
15.
Genome Announc ; 4(5)2016 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-27789638

RESUMO

Echovirus 18 is a member of the genus Enterovirus, family Picornaviridae, which can cause meningitis in children. Here, we report the echovirus 18 complete genome sequence, which was isolated from the cerebrospinal fluid of a child with aseptic meningitis in Hebei Province, China.

16.
Bing Du Xue Bao ; 30(4): 483-8, 2014 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-25272607

RESUMO

Epidemics of hand, foot and mouth disease (HFMD) have mainly been caused by Coxsackievirus A16 (CVA16) and Enterovirus A 71 (EV-A71), which circulated alternatively or together in the affected area. CVA16 has caused numerous outbreaks and epidemics in multiple countries and geographical regions, and has become an important public health problem. Based on an analysis of the complete VP1 coding region, all CVA16 strains can be divided into genotypes A, B1, and B2. Furthermore, genotype B1 can be divided into subgenotypes B1a, B1b, and B1c. After 2000, no reports of genotype B2 virus strains have been reported. All of the CVA16 strains reported in mainland China have belonged to subgenotypes B1a and B1b. Most CVA16-associated infections cause only mild symptoms; however, some CVA16 infections can lead to severe complications and even death. Vaccination is considered to be the most effective method to control the transmission and infection rate of this virus. A number of research groups are studying various vaccine types, including inactivated vaccines, genetic engineering vaccines, and DNA vaccines, amongst others. In this review, an overview is provided of the research advances in molecular epidemiology and vaccines of CVA16.


Assuntos
Infecções por Coxsackievirus/virologia , Enterovirus Humano A/genética , Vacinas Virais/imunologia , Animais , China , Infecções por Coxsackievirus/epidemiologia , Infecções por Coxsackievirus/imunologia , Infecções por Coxsackievirus/prevenção & controle , Enterovirus Humano A/classificação , Enterovirus Humano A/isolamento & purificação , Humanos , Epidemiologia Molecular , Vacinas Virais/administração & dosagem , Vacinas Virais/genética
17.
Bing Du Xue Bao ; 30(3): 226-32, 2014 May.
Artigo em Chinês | MEDLINE | ID: mdl-25118375

RESUMO

This study aims to construct inactivated coxsackievirus A16 (CVA16) vaccine and to investigate its protective effect in ICR mice. A clinical isolate of CVA16, 521-01T, was cultured in VERO cells, inactivated by formaldehyde, and purified by ultracentrifugation for vaccine preparation. Purity and other characteristics of the vaccine were determined by SDS-PAGE and Western blot. Female ICR mice were subcutaneously inoculated with inactivated CVA16 or Al(OH)3-absorbed CVA16, followed by booster immunization at the end of 2 and 4 weeks. CVA16-specific IgG titers in serum were determined by ELISA, and titers of neutralizing antibodies were determined by viral neutralization assay. The immunity of T lymphocytes was evaluated by IFN-gamma ELISPOT assay. The protective effect was evaluated by challenging the neonatal offspring (< 48 hours) of vaccinated female mice with 1 000 LD50 of CVA16 521-01T. The mortality rates of different groups were compared. The results showed that Al(OH)3 +CVA16 could induce high titers of specific IgG antibodies in ICR mice. After being boosted two times, the serum IgG antibody titer could reach up to 1 : 1 x 10(5) (P = 0.000), and neutralizing antibody titer was higher than 1 : 256. Additionally, more spot forming cells were induced in the immunized groups than in the negative controls. The maternal antibodies showed protective effect in 100% of the neonatal mice challenged with 1 000 LD50 of CVA16 521-01T. The inactivated CVA16 vaccine has ideal immunogenicity and immunoprotective effect. This research lays a foundation for the development and evaluation of CVA16 vaccines.


Assuntos
Infecções por Enterovirus/imunologia , Infecções por Enterovirus/prevenção & controle , Enterovirus/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Infecções por Enterovirus/virologia , Feminino , Humanos , Imunização , Camundongos , Camundongos Endogâmicos ICR , Linfócitos T/imunologia , Linfócitos T/virologia , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia , Vacinas Virais/administração & dosagem
18.
PLoS One ; 8(12): e82861, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24340064

RESUMO

Coxsackievirus A16 (CVA16) is responsible for nearly 50% of all the confirmed hand, foot, and mouth disease (HFMD) cases in mainland China, sometimes it could also cause severe complications, and even death. To clarify the genetic characteristics and the epidemic patterns of CVA16 in mainland China, comprehensive bioinfomatics analyses were performed by using 35 CVA16 whole genome sequences from 1998 to 2011, 593 complete CVA16 VP1 sequences from 1981 to 2011, and prototype strains of human enterovirus species A (EV-A). Analysis on complete VP1 sequences revealed that subgenotypes B1a and B1b were prevalent strains and have been co-circulating in many Asian countries since 2000, especially in mainland China for at least 13 years. While the prevalence of subgenotype B1c (totally 20 strains) was much limited, only found in Malaysia from 2005 to 2007 and in France in 2010. Genotype B2 only caused epidemic in Japan and Malaysia from 1981 to 2000. Both subgenotypes B1a and B1b were potential recombinant viruses containing sequences from other EV-A donors in the 5'-untranslated region and P2, P3 non-structural protein encoding regions.


Assuntos
Biologia Computacional/métodos , DNA Viral/análise , Enterovirus/genética , Doença de Mão, Pé e Boca/virologia , Regiões 5' não Traduzidas , Sequência de Bases , China , Análise por Conglomerados , Primers do DNA/genética , Enterovirus/classificação , Genoma Viral , Genômica , Genótipo , Doença de Mão, Pé e Boca/epidemiologia , Humanos , Epidemiologia Molecular , Dados de Sequência Molecular , Filogenia , Recombinação Genética , Análise de Sequência de DNA
19.
Bing Du Xue Bao ; 29(3): 273-9, 2013 May.
Artigo em Chinês | MEDLINE | ID: mdl-23905470

RESUMO

To study the epidemic characteristics of human rhinovirus (HRV) in children with acute respiratory infections in Gansu Province. 286 throat swabs were collected from children with acute respiratory in fections in Gansu Province during 2011. Multiplex reverse transcription-PCR (multiplex RT-PCR) assay was used to screen those specimens for detection of common respiratory tract pathogens. For HRV-positive samples, nested reverse transcription polymerase chain reaction (nested RT-PCR) was performed to amplify VP1 and VP4/VP2 gene fragments of HRV. The VP4/VP2 and VP1 regions of HRV-positive samples were sequenced and performed genotype analysis. Of 286 specimens fested, 27 were positive for HRV by multiplex RT-PCR and nested RT-PCR, of which 16 children were made (16/185), 8.64%) and 11 female (11/101,10.89%). The positive rate was 9.44% (27/286). The mean age of HRV-positive children was 3 years in this study, children less than one year old had the highest proportion 44.4% (12/ 27, 44.4%). The highest HRV positive rate fell on May, 2011 (6/27, 22.2%). Common cold accounted for the highest proportion, 12.24% (12/98) followed by pneumonia, 8.50% (13/153). The remaining 2 cases were bronchitis. Sequence analysis showed HRV A was the predominant genotype in Gansu Province in 2011, accounting for 84.62% (22/26) of positive cases, followed by HRV C (11.54%, 3/26) and only one HRV B was detected (3.85%, 1/26). HRV could be detected throughout the year in Gansu Province and primarily infected children under one year old. The group A was the epidemic genotype of HRV and move than one genotype existed in Gansu Province during 2011.


Assuntos
Infecções por Picornaviridae/virologia , Infecções Respiratórias/virologia , Rhinovirus/isolamento & purificação , Adolescente , Criança , Pré-Escolar , China/epidemiologia , Feminino , Humanos , Lactente , Masculino , Dados de Sequência Molecular , Filogenia , Infecções por Picornaviridae/epidemiologia , Infecções Respiratórias/epidemiologia , Rhinovirus/classificação , Rhinovirus/genética , Estações do Ano
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