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Objective@#To investigate the clinical and epidemiological characteristics of Coronavirus HKU1 (Human CoV-HKU1) and NL63 (Human CoV-NL63) in children with acute respiratory tract infection in Nanjing.@*Methods@#From August 2009 to July 2011, 1 286 respiratory samples were collected from the outpatient and hospitalized children in the Children′s Hospital of Nanjing Medical University. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect HCoV-HKU1 and NL63 genes, besides, positive samples were used for common respiratory virus screening. The positive amplification products were cloned, sequenced, homologous and phylogenetic analysis was conducted by molecular biological method .@*Results@#The detection rate of HCoV-HKU1 was 1.1% (14/1 286), the positive sequences shared a 98.2%-100% nucleotide identity with the HCoV-HKU1 strains and mixed infection rate was 92.9%. The main clinical diagnoses were bronchitis, bronchopneumonia and bronchiolitis. The clinical manifestations were cough, fever, wheezing. The detection rate of HCoV-NL63 was 1.5% (19/1 286), the positive sequences shared a 95.6%-100% nucleotide identity with the HCoV-NL63 strains and mixed infection rate were 63.2%. The main clinical diagnosis were acute upper respiratory tract infection, bronchitis, bronchopneumonia. The clinical manifestations were fever, cough, expectoration. No deaths were found in both HCoV-HKU1 and NL63 infections.@*Conclusions@#From August 2009 to July 2011, HCoV-HKU1 and NL63 were detected in children with respiratory tract infection in Nanjing area. HCoV-HKU1 infected cases were lower respiratory tract infection, epidemic in winter and spring, infected cases were mainly under 1 years of age, HCoV-NL63 infected cases including upper respiratory and lower respiratory tract infection, epidemic in the season of summer and autumn. The infected cases were mainly at the age rank from 1 year to 3 years. The clinical manifestations of children infected with coronavirus HKU1 and NL63 are not specificity.
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Objective@#To investigate the human bocavirus (HBoV) infection in the children diagnosed with brochiolitis, incomparison with the clinical characteristics of bronchiolitis of HBoV vs. respiratory syncytial virus (RSV) infection alone.@*Methods@#A total of 396 throat swabs were obtained from children diagnosed with bronchiolitis from January 2015 to December 2016 in Pediatric Asthma Center of Gansu Maternal and Child Health Care Hospital, Lanzhou. Specimens were tested for the nucleic acids of HBoV, RSV and other 6 common respiratory viruses by nested-polymerase chain reaction (nested PCR() and reverse transcription-polymerase chain reaction (RT-PCR), and the epidemic status, clinical characteristics of HBoV and RSV were analyzed and compared with each other.@*Results@#The positive rate of virus infection was 53.54%, and HBoV and RSV infections were 9.84% and 24.49% in 396 cases. The numbers of cases of HBoV single infection, RSV single infection, HBoV and RSV mixed infection were 29, 86 and 5. The number of boys infected with HBoV was 27. There was statistical significance in the difference between the genders. The statistical significance also existed in difference of age. The babies at ages ranging from 6 to 12 months had the hifgest positive rate. The first incidence peak of the infection of HBoV was in October 2015. The children with HBoV infection, compared with RSV patients, presented more often with vomiting, diarrhea (P<0.05), while symptoms such as the occurrence of dyspnea, hypoxemia and the hospitalization time were all lower.@*Conclusions@#HBoV is one of the possible causes of brochiolitis in infants, its infection distributed over the whole year. The clinical symptoms, laboratory and radio-graphic changes are similar between the HBoV and RSV infections, the only difference was that the HBoV infection was comparatively mild.
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Objective@#To express envelope protein of ZIKA virus in baculovirus expression system.@*Methods@#Full-length E gene of ZIKA virus was obtained by DNA synthesis and inserted into vector pFastBac1. The constructed recombinant baculovirus transfer vector pFB1-E was transformed to competent DH10Bac cells. The obtained skeleton plasmid rBacmid-E was transfected to sf9 cells, and the constructed recombinant baculovirus rBac-E was determined for titer, for insertion of E gene by PCR, and for expression of E protein by IFA and Western blotting.@*Results@#PCR proved that skeleton plasmid rBacmid-E was constructed correctly. The titer of rBac-E of passage 3 was 2.58×105pfu/ml. The genome of infected cells virus was extracted, the gene band at length of 3 830 bp was observed after PCR amplification. Indirect immunofluorescence of the infected cells showed the specific green fluorescence, 55×103specific band was determined by Western blotting identification in the cell pellet of the infected recombinant baculovirus rBac-E.@*Conclusions@#The recombinant baculovirus with E gene of ZIKA virus was successfully constructed, which laid a foundation of further study on the function of E protein and the vaccine of ZIKA virus.
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Objective To investigate the viral prevalence of acute lower respiratory tract infection (ALRTI)in children. Methods Totally 1165 children with clinical diagnosis of ALRTI during the period from August 2007 to September 2008 were involved in our study. The nasopharyngeal aspirate specimen was collected from each patient. RT-PCRs were performed to detect common respiratory tract viruses including respiratory syncytial virus (RSV), rhinovirus (HRV), parainfluenza virus (PIV, type 1 -3 ), influzenza virus type A and B (IFA,IFB), and PCR was used to detect adenovirus (ADV). Results 783 patients were identified to have at least one kind of viral pathogens and the overall positive rate was 67.2%. The most common virus was RSV (27%), followed by HRV ( 17.4% ) and PIV3 ( 13. 9% ). The peak infection seasons were winter and autumn. The etiological spectrum of ALRTI varied in different age groups. Two or more viruses were identified in 284 out of 783 cases ( 36. 3% ). The mixed infection rate was high in infants under 1 year old (63.7%) while it decreased to 8. 5% in children older than 3 years of age. Conclusion RSV, HRV and PIV3 were the most predominant pathogens in children less than 1 year old. The peak infection seasons were winter and autumn. The infection rate and mixed infection rate in infants under 1 year old were highest. The most common style was RSV and HRV mixed infection.