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1.
Emerg Microbes Infect ; 9(1): 246-255, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31996093

RESUMO

Human coronavirus NL63 (HCoV-NL63) is primarily associated with common cold in children, elderly and immunocompromised individuals. Outbreaks caused by HCoV-NL63 are rare. Here we report a cluster of HCoV-NL63 cases with severe lower respiratory tract infection that arose in Guangzhou, China, in 2018. Twenty-three hospitalized children were confirmed to be HCoV-NL63 positive, and most of whom were hospitalized with severe pneumonia or acute bronchitis. Whole genomes of HCoV-NL63 were obtained using next-generation sequencing. Phylogenetic and single amino acid polymorphism analyses showed that this outbreak was associated with two subgenotypes (C3 and B) of HCoV-NL63. Half of patients were identified to be related to a new subgenotype C3. One unique amino acid mutation at I507 L in spike protein receptor binding domain (RBD) was detected, which segregated this subgenotype C3 from other known subgenotypes. Pseudotyped virus bearing the I507 L mutation in RBD showed enhanced entry into host cells as compared to the prototype virus. This study proved that HCoV-NL63 was undergoing continuous mutation and has the potential to cause severe lower respiratory disease in humans.

2.
Eur J Clin Microbiol Infect Dis ; 38(12): 2355-2364, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31489496

RESUMO

To investigate the features of paramyxovirus respiratory syncytial virus (RSV), parainfluenza virus (PIV), and human metapneumovirus (HMPV) infection and determine the effect of meteorological conditions in Guangzhou, a subtropical region of southern China. We collected 11,398 respiratory samples from hospitalized pediatric patients with acute respiratory illness between July 2009 and June 2016 in Guangzhou. The samples were tested simultaneously for 18 respiratory pathogens using real-time PCR. Local meteorological data were also collected for correlation analysis. Of 11,398 patients tested, 5606 (49.2%) patients tested positive for one or more pathogens; RSV, PIV, and HMPV were the first, sixth, and ninth most frequently detected pathogens, in 1690 (14.8%), 502 (4.4%), and 321 (2.8%) patients, respectively. A total 17.9% (4605/5606) of patients with positive results had coinfection with other pathogens. Significant differences were found in the prevalence of RSV, PIV, and HMPV among all age groups (p < 0.001). RSV and HMPV had similar seasonal patterns, with two prevalence peaks every year. PIV appeared alternatively with RSV and HMPV. Multiple linear regression models were established for RSV, PIV, and HMPV prevalence and meteorological factors (p < 0.05). RSV and PIV incidence was negatively correlated with monthly mean relative humidity; RSV and HMPV incidence was negatively correlated with sunshine duration; PIV incidence was positively correlated with mean temperature. We described the features of paramyxovirus infection in a subtropical region of China and highlighted the correlation with meteorological factors. These findings will assist public health authorities and clinicians in improving strategies for controlling paramyxovirus infection.

3.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 36(3): 407-413, 2019 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-31232543

RESUMO

Tree shrew is a novel and high-quality experimental animal model. In this study, the real-time polymerase chain reaction methods were established to detect infection-related cytokines interleukin-6 (IL-6), IL-8, IL-10, IL-17A, interferon-γ (IFN-γ) and housekeeping gene glyceraldehyde-phosphate dehydrogenase ( GAPDH) of tree shrew. The results indicated that the establised methods had good specificity. The high point of the linear range of these reagents reached 1 × 10 10 copies, and the low points ranged from 10 copies (IL-6, IL-17A), 100 copies (IL-10, GAPDH) to 1 000 copies (IL-8, IFN-γ). In this interval, the linear correlation coefficient R 2 of each reagent was greater than 0.99. The lowest detectable values of IL-6, IL-8, IL-10, IL-17A, IFN-γ and GAPDH were 8, 8, 4, 8, 128 and 4 copies, respectively. The results showed that the established detection methods had good specificity, sensitivity and wide linear range. The methods were suitable for detection of multiple concentration range samples, and could be used for the subsequent studies of tree shrew cytokines.


Assuntos
Citocinas/análise , Reação em Cadeia da Polimerase em Tempo Real , Musaranhos , Animais
4.
Virus Res ; 256: 100-106, 2018 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-30096411

RESUMO

Human adenoviruses (HAdV) 3 and 7 can cause acute respiratory disease epidemics and outbreaks. Identification of neutralizing epitopes is vital for surveillance and vaccine development. In this study, we generated the recombinant capsid-chimeric human adenoviruses rAd3E-Fk7, containing the Ad3E backbone and the HAdV-7 fiber knob, and rAd3E-H7Fk7, which contain an Ad3E backbone but HAdV-7 hexon and fiber knob. In vitro neutralization tests with these chimeric adenoviruses using both mouse and human antisera indicated that hexon and fiber knob are the major targets recognized by neutralizing antibodies against HAdV-3 or HAdV-7, and other capsid proteins including the penton base and fiber shaft may not contribute to neutralizing antibody responses. In conclusion, both hexon and fiber knob structures in HAdV-3 and HAdV-7 may be the proteins which induce neutralizing antibody responses and thus may be important for adenovirus vaccine and drug development.


Assuntos
Adenovírus Humanos/genética , Adenovírus Humanos/imunologia , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Recombinação Genética , Animais , Antígenos Virais/genética , Antígenos Virais/imunologia , Epitopos de Linfócito B/imunologia , Humanos , Camundongos , Testes de Neutralização
5.
BMC Infect Dis ; 18(1): 329, 2018 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-30012099

RESUMO

BACKGROUND: Human bocavirus 1 (HBoV1) is an important cause of acute respiratory illness (ARI), yet the epidemiology and effect of meteorological conditions on infection is not fully understood. To investigate the distribution of HBoV1 and determine the effect of meteorological conditions, hospitalized pediatric patients were studied in a subtropical region of China. METHODS: Samples from 11,399 hospitalized pediatric patients (≤14 years old), with ARI were tested for HBoV1 and other common respiratory pathogens using real-time PCR, between July 2009 and June 2016. In addition, local meteorological data were collected. RESULTS: Of the 11,399 patients tested, 5606 (49.2%) were positive for at least one respiratory pathogen. Two hundred forty-eight of 11,399 (2.2%) were positive for HBoV1 infection. Co-infection was common in HBoV1-positive patients (45.2%, 112/248). A significant difference in the prevalence of HBoV1 was found in patients in different age groups (p < 0.001), and the peak prevalence was found in patients aged 7-12 months (4.7%, 56/1203). Two HBoV1 prevalence peaks were found in summer (between June and September) and winter (between November and December). The prevalence of HBoV1 was significantly positively correlated with mean temperature and negatively correlated with mean relative humidity, and the mean temperature in the preceding month had better explanatory power than the current monthly temperature. CONCLUSIONS: This study provides a better understanding of the characteristics of HBoV1 infection in children in subtropical regions. Data from this study provide useful information for the future control and prevention of HBoV1 infections.


Assuntos
Clima , Hospitalização , Bocavirus Humano , Infecções por Parvoviridae/epidemiologia , Infecções Respiratórias/epidemiologia , Pré-Escolar , China/epidemiologia , Coinfecção , Feminino , Bocavirus Humano/genética , Humanos , Lactente , Masculino , Infecções por Parvoviridae/etiologia , Infecções por Parvoviridae/virologia , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Infecções Respiratórias/etiologia , Infecções Respiratórias/virologia , Estações do Ano
6.
Antiviral Res ; 154: 17-25, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29626491

RESUMO

Human adenovirus (Ad) species B contains several of the most important types associated with acute respiratory diseases, Ad3, -7, -14 and -55, which often lead to severe lower respiratory tract diseases and epidemic outbreaks. However, there is currently no Ad vaccine approved for general use. The major capsid protein, hexon, is the primary determinant recognized by neutralizing antibodies (NAbs). In this study, four recombinant Ads that have the same genome sequence as Ad3 with the exception of the hexon genes, rAd3EGFP, rAd3H7, rAd3H14 and rAd3H55, were combined as a tetravalent Ad candidate vaccine against Ad3, -7, -14 and -55. The replication efficiencies of chimeric rAd3H14, rAd3H7 and rAd3H55 were similar to that of rAd3EGFP. Recombinant rAd3EGFP, rAd3H7, rAd3H14 and rAd3H55 induced high titers of NAbs against Ad3, -7, -14 and -55, respectively, which were comparable to those induced by wild-type Ads. The mixture of the four recombinant Ads in equal proportions, rAdMix, or rAdMix inactivated by ß-propiolactone, induced balanced NAb responses against Ad3, -7, -14 and -55 in mice without reciprocal immunological interference. In co-culture the four recombinant Ads replicated with a similar efficiency without reciprocal inhibition, and the progeny virions may be chimeric. Purified co-culture, rAdMix-C, also elicited balanced immune responses, suggesting a simple method for multivalent vaccine production. These results indicate the possible advantage of the four Ads as a live combined vaccine. Importantly, pre-immunization with rAdMix conferred protection against Ad3, -7, -14 or -55 challenge in mice in vivo. Thus, this research provides a novel tetravalent Ad vaccine candidate against Ad3, -7, -14 and -55.


Assuntos
Infecções por Adenoviridae/prevenção & controle , Vacinas contra Adenovirus/imunologia , Anticorpos Antivirais/sangue , Proteínas do Capsídeo/imunologia , Doença Aguda , Infecções por Adenoviridae/imunologia , Adenovírus Humanos/classificação , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Proteínas do Capsídeo/genética , Feminino , Vetores Genéticos , Humanos , Camundongos Endogâmicos BALB C , Vacinação
7.
BMJ Open ; 8(2): e019308, 2018 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-29437754

RESUMO

OBJECTIVES: Human metapneumovirus (HMPV) is one of the most important respiratory viral pathogens affecting infants and children worldwide. Our study describes the epidemiological and clinical characteristics of HMPV present in patients hospitalised with acute respiratory illness (ARI) in Guangzhou, Southern China. STUDY DESIGN: A cross-sectional study. SETTING: Two tertiary hospitals in Guangzhou. PARTICIPANTS AND METHODS: Throat swabs were collected over a 3-year period from 5133 paediatric patients (≤14 years) hospitalised with ARI. Patients who are HMPV positive with clinical presentations (101/103) were recorded for further analysis. RESULTS: Of the 5133 patients included in the study, 103 (2.0%) were positive for HMPV. HMPV was more prevalent in children ≤5 years (2.2%, 98/4399) compared with older children (>5-14 years) (0.7%, 5/734) (P=0.004). Two seasonal HMPV peaks were observed each year and mainly occurred in spring and early summer. Overall, 18.4% (19/103) of patients who are HMPV positive were codetected with other pathogens, most frequently respiratory syncytial virus (36.8%, 7/19). Patients who are HMPV positive presented with a wide spectrum of clinical features, including cough (100.0%, 101/101), abnormal pulmonary breath sound (91.1%, 92/101), fever (88.1%, 89/101), expectoration (77.2%, 78/101), coryza (50.5%, 51/101) and wheezing (46.5%, 47/101). The main diagnosis of patients who are HMPV positive was bronchopneumonia (66.7%, 56/84). Fever (≥38˚C) (91.6%, 76/83) was detected more often in patients with only HMPV detected than in patients with HMPV plus other pathogen(s) detected (72.2%, 13/18) (P=0.037), whereas diarrhoea was more common in patients with HMPV plus other pathogen(s) detected (22.2%, 4/18), compared with patients with HMPV only (3.6%, 3/83) (P=0.018). CONCLUSIONS: HMPV is an important respiratory pathogen in children with ARI in Guangzhou, particularly in children ≤5 years old. HMPV has a seasonal variation. Bronchopneumonia is a major diagnosis in patients who are HMPV positive.


Assuntos
Metapneumovirus/isolamento & purificação , Infecções por Paramyxoviridae/epidemiologia , Vírus Sincicial Respiratório Humano/isolamento & purificação , Doenças Respiratórias/virologia , Estações do Ano , Adolescente , Distribuição por Idade , Criança , Pré-Escolar , China/epidemiologia , Estudos Transversais , Feminino , Hospitalização , Humanos , Lactente , Masculino , Infecções por Paramyxoviridae/complicações , Prevalência , Doenças Respiratórias/epidemiologia
8.
Eur J Clin Microbiol Infect Dis ; 37(2): 363-369, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29214503

RESUMO

Human coronaviruses (HCoV) OC43, 229E, NL63, and HKU1 are common respiratory viruses which cause various respiratory diseases, including pneumonia. There is a paucity of evidence on the epidemiology and clinical manifestations of these four HCoV strains worldwide. We collected 11,399 throat swabs from hospitalized children with acute respiratory tract infection from July 2009 to June 2016 in Guangzhou, China. These were tested for four strains of HCoV infection using real-time polymerase chain reaction (PCR). HCoV-positive patients were then tested for 11 other respiratory pathogens. 4.3% (489/11399) of patients were positive for HCoV, of which 3.0% were positive for OC43 (346/11399), 0.6% for 229E (65/11399), 0.5% for NL63 (60/11399), and 0.3% for HKU1 (38/11399). Patients aged 7-12 months had the highest prevalence of HCoV and OC43 when compared with other age groups (p < 0.001). The peak seasons of infection varied depending on the HCoV strain. Patients infected with a single strain of HCoV infection were less likely to present fever (≥ 38 °C) (p = 0.014) and more likely to present pulmonary rales (p = 0.043) than those co-infected with more than one HCoV strain or other respiratory pathogens. There were also significant differences in the prevalence of certain symptoms, including coughing (p = 0.032), pneumonia (p = 0.026), and abnormal pulmonary rales (p = 0.002) according to the strain of HCoV detected. This retrospective study of the prevalence of four HCoV strains and clinical signs among a large population of pediatric patients in a subtropical region of China provides further insight into the epidemiology and clinical features of HCoV.


Assuntos
Coronavirus Humano 229E/isolamento & purificação , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Coronavirus Humano NL63/isolamento & purificação , Coronavirus Humano OC43/isolamento & purificação , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/epidemiologia , Adolescente , Criança , Pré-Escolar , China/epidemiologia , Infecções por Coronavirus/virologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Infecções Respiratórias/virologia , Estudos Retrospectivos
9.
PLoS One ; 11(10): e0165108, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27764220

RESUMO

Respiratory syncytial virus (RSV) is one of the most important pathogenic infections of children and requires in-depth research worldwide, and especially in developing countries. We used a novel multiplex real-time PCR to test 5483 patients (≤ 14 years old) hospitalized with respiratory illness in Guangzhou, China, over a 3-year period. Of these patients, 729 were positive for RSV-A (51.2%, 373/729) or RSV-B (48.8%, 356/729), but none was infected with both viruses. Two seasonal peaks in total RSV were detected at the changes from winter to spring and from summer to autumn. RSV-B was dominant in 2013 and RSV-A in 2015, whereas RSV-A and RSV-B cocirculated in 2014. The clinical presentations of 645 RSV-positive patients were analyzed. Bronchiolitis, dyspnea, coryza, vomiting, poor appetite, and diarrhea occurred more frequently in RSV-A-positive than RSV-B-positive patients, whereas chill, headache, myalgia, debility, and rash etc. were more frequent in RSV-B-positive than RSV-A-positive patients, suggesting specific clinical characteristics for RSV-A and RSV-B. Coinfectons with other pathogens were common and diverse. Bronchiolitis, fever (≥ 38°C), and poor appetite were more frequent in patients with single RSV infections than in coinfected patients, suggesting the key pathogenic activity of RSV. Analysis of the relationships between the comparative viral load and clinical presentations showed significant differences in bronchiolitis, fever (≥ 38°C), and rash etc. among patients with different viral loads. This study provides a novel rapid method for detecting RSV subgroups, and provides new insights into the epidemiology and clinical implications of RSV.


Assuntos
Reação em Cadeia da Polimerase Multiplex/métodos , Faringe/virologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Infecções por Vírus Respiratório Sincicial/epidemiologia , Vírus Sincicial Respiratório Humano/classificação , Adolescente , Criança , Pré-Escolar , China/epidemiologia , Coinfecção/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , RNA Viral/análise , Infecções por Vírus Respiratório Sincicial/patologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Sensibilidade e Especificidade
10.
PLoS One ; 10(9): e0138684, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26406339

RESUMO

BACKGROUND: Respiratory tract infections (RTIs) are a heavy burden on society. However, due to the complex etiology of RTIs, the clinical diagnosis, treatment, and prevention of these infections remain challenging, especially in developing countries. METHODS: To determine the epidemiological and clinical characteristics of 18 respiratory pathogens, we analyzed 12,502 patients with acute respiratory infections (ARIs) by performing polymerase chain reaction (PCR) on patient pharyngeal swabs. RESULTS: Samples positive for at least 1 pathogen were obtained from 48.42% of the total patients. Of these pathogen-positive patients, 17.99% were infected with more than 1 pathogen. Of the 18 pathogens analyzed, four were detected with a positive detection rate (PDR) > 5%: influenza A virus (IAV) > respiratory syncytial virus (RSV) >Mycoplasma pneumoniae (MP) > human coronavirus (HCoV). The pathogens with the 4 highest co-infection rates (CIRs) were as follows: HCoV > human bocavirus (HBoV) > enterovirus (EV) > parainfluenza virus (PIV). The overall positive detection rate (PDR) varied significantly according to patient age, the season and year of detection, and the disease subgroup, but not according to patient sex. The individual PDRs of the pathogens followed 3 types of distributions for patient sex, 4 types of distributions for patient age, 4 types of seasonal distributions, 2 types of seasonal epidemic trends, 4 types of yearly epidemic trends, and different susceptibility distributions in the disease subgroups. Additionally, the overall CIR showed significantly different distributions according to patient sex, patient age, and the disease subgroup, whereas the CIRs of individual pathogens suggested significant preference characteristics. CONCLUSION: IAV remains the most common pathogen among the pathogens analyzed. More effort should be directed toward the prevention and control of pathogens that show a trend of increasing incidence such as HCoV, human adenovirus (ADV), and RSV. Although clinically distinguishing specific pathogens responsible for RTIs is difficult, the epidemiological and clinical characteristics of the various RTI-causing agents could provide clues for clinicians, thereby informing decisions regarding prevention and medication and guiding appropriate public health strategies.


Assuntos
Bactérias/classificação , Faringe/microbiologia , Infecções Respiratórias/classificação , Infecções Respiratórias/epidemiologia , Vírus/classificação , Adolescente , Adulto , Bactérias/genética , Bactérias/isolamento & purificação , Criança , Pré-Escolar , China/epidemiologia , Feminino , Hospitalização , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Infecções Respiratórias/microbiologia , Estações do Ano , Vírus/genética , Vírus/isolamento & purificação , Adulto Jovem
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