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Objective:To investigate the epidemiology of pathogens of acute respiratory tract infection (ARTI) in children in Guangzhou area.Methods:A total of 13 610 hospitalized children with ARTI in Guangzhou Women and Children′s Medical Center from January 2018 to December 2021 were enrolled. Throat swab specimens were collected, and fluorescent quantitative polymerase chain reaction (PCR) was performed to detect 11 respiratory pathogens, including respiratory syncytial virus (RSV), adenovirus (ADV), parainfluenza virus (PIV), human rhinovirus (HRV), human bocavirus (HBoV), human metapneumovirus (HMPV), enterovirus (EV), influenza A virus (IFA), influenza B virus (IFB), Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP). Grouping according to age (< one year group, one to < three years group, three to < six years group, six to 14 years group) and season. Chi-square test was used for statistical analysis. Results:At least one pathogen was detected in 6 331 cases among 13 610 patients, and the overall positive rate was 46.52%. The detection rates from high to low were as follows: RSV (13.75%(1 872/13 610)), ADV (4.82%(656/13 610)), PIV (4.82%(656/13 610)), MP (4.54%(618/13 610)), HRV (3.39%(462/13 610)), HBoV (2.64%(359/13 610)), HMPV (2.59%(352/13 610)), EV (1.76%(239/13 610)), IFA (1.29%(176/13 610)), IFB (0.90%(122/13 610)) and CP (0.30%(41/13 610)). The positive rate of viral detection showed significant differences among different age groups ( χ2=49.91, P<0.001), and the highest positive rate was in the age group of one to <three years (50.83%(2 196/4 320)). The positive rate of viral detection showed a significant difference in terms of seasonal distribution ( χ2=13.90, P=0.003), with a peak prevalence in summer (48.76%(1 498/3 072)). Conclusions:RSV, ADV, PIV, MP and HRV are important pathogens causing ARTI in children in Guangzhou area. The distribution of pathogens in children with ARTI is associated with age and season.
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The pineal gland is a neuroendocrine gland closely related to human aging.Melatonin is a kind of indole neuroendocrine hormone secreted by pineal gland which is essential for maintaining physiological function.Many researches have found that melatonin plays a key protective role against aging-related cardiovascular diseases.In this article, the advanced studies at home and abroad on melatonin and aging-related cardiovascular diseases are reviewed, and the related physiological functions and mechanisms are discussed.
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Objective To study the epidemiology of hand,foot,and mouth disease (HFMD) and the spectrum of serotypes in the other enterovirus (EV) (non-EV-A71 and non-Coxsaekievirus group A 16,CV-A 16) from 2016 to 2017 in Guangzhou,to provide the basis for its treatment,prevention and control.Methods Enteroviruses universal type,EV-A71 and CV-A16 were detected by real time reverse transeription-polymerase chain reaction in the specimens from HFMD suspected patients from 2016 to 2017.The positive specimens of non-EV-A71 and non-CV-A16 were amplified and sequenced based on 5'-untranslated region (UTR) region.The spectrum of serotypes was analyzed with BLAST in NCBI on the basis of 5'-UTR region.Results A total of 25779 specimens from HFMD patients were collected during 2016-2017,16 300 (63.23 ％) of which were positive.The positive rates of EV-A71,CV-A16,non-EV-A71 and non-CV-A16 were 4.57％ (1 178/25 779),12.70％ (3 274/25 779) and 45.96％ (11 848/25779),respectively.The average positive rate of non-EV-A71 and non-CV-A16 in 2017 was 55.68％,which was higher than that in 2016.Sequence analysis showed that there were 16 genotypes in 95 non-EV-A71 and non-CV-A16 positive specimen,including CV-A6,CV-A10,CV-A4,CV-A2,CV-A8,CV-A12,CV-A9,Coxsakievirus B5 (CV-B5),CV-B2,CV-B4,CV-B3,Echovirus 1 (E1),E16,E30,E2 and E18.CV-A6 (26.32％),and CV-A10 (15.79％) were the most common genotypes,followed by CV-A4 (6.32％)、CV-A8(4.21％),and CV-A2 (4.21％).Conclusions The infection rate of EV-A71 is very low during 2016-2017.From April to July 2016,there is a small peak of CV-A16 infection.The non-EV-A71 and non-CV-A16 enterovirus becomes the main causative agent of HFMD during 2016 to 2017.CV-A6 and CV-A10 are the most prevalent pathogens of non-EV-A71 and non-CV-A16 enterovirus.Research and monitoring of CV-A6,CV-A10 as the main non-EV-A71and non-CV-A16 virus should be strengthened.
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Objective To express and preliminary identify scavenger receptor B2 (SCARB2)protein.Methods SCARB2 cDNA was amplified by reverse transcription-polymerase chain reaction (RT-PCR)from mRNA extracted from RD cells,and cloned into pMD19-T vector.Expression vector pET28a(+)/SCARB2 was constructed,and SCARB2 protein was expressed in prokaryotic ex-pression system.Obtained recombinant proteins were identified by detection of Western blot using His labeled monoclonal antibody.Results Recombinant SCARB2 proteins,expressed by induction of isopropy-β-D-thiogalactoside (IPTG),were success-fully purified and specifically recognized by His labeled monoclonal antibody.Conclusion SCARB2 proteins could be expressed and identified successfully,which could provide reference for researching mechanism of enterovirus type 71 (EV71)and scavenger re-ceptor protein,and for preparation of SCARB2 monoclonal antibodies.
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Objective To determine the viral etiology and its epidemic features of community-acquired pneumonia ( CAP) among pediatric inpatients in Guangzhou.Methods A total of 1 539 children with CAP admitted in Guangzhou Women and Children’ s Medical Center during June 2012 and June 2013 were enrolled in the study.Throat swab specimens were collected, and fluorescence quantitative polymerase chain reaction ( FQ-PCR) was performed to detect 11 respiratory pathogens.SPSS 17.0 was used for data processing, and χ2 test was performed to compare the infection rates among different groups.Results Among 1 539 patients, 550 cases (35.7%) were infected with at least one pathogen, and 101 (6.6%) were infected with two or more pathogens.The most popular viral etiologies were respiratory syncytial virus (RSV) (102, 6.6%), rhinovirus (RHV)(101, 6.6%), adenovirus (ADV) (78, 5.1%), influenza virus A (IVA) (78, 5.1%) and bocavirus (HBOV) (74, 4.8%).RSV infection often occurred in children with age≤3 years, while ADV or IVA infection often occurred in those with age >3 years.RSV infection rate peaked in winter and spring, IVA infection rate peaked in spring and summer, while ADV and HBOV infection rates peaked in summer.The rate of multiple infections in critically ill children (22/135, 16.3%) was significantly higher than that in other CAP patients (79/1 404,5.6%,χ2 =116.049, P<0.01).Conclusions Viral infection is common in pediatric inpatients with CAP, and RSV infection is the most popular.Multiple infections are more often to cause critical conditions.
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ObjectiveTo conduct a molecular epidemiological study on human metapneumovirus (hMPV) among pediatric patients in Guangzhou. MethodsA total of 1 840 clinical specimens were obtained from pediatric patients with respiratory infections in Guangzhou Women and Children' s Medical Center in 2010.hMPV was detected by real-time TaqMan RT-PCR in clinical specimens.F gene was amplified and the PCR-products were directly sequenced. ResultsIn 1 840 clinical specimens, 66 werehMPV-positive with a positive rate of 3.59％. hMPV was detected in all specimens except those collected in September and October, and the highest positive hMPV rate occurred in April (6.09％). The F genes of 3 randomly selected strains and hMPVgz01 ( isolated in 2008) were compared with subgroups A1, A2, B1,B2 and C, and the highest homology was with BJ1887 strain of genotype A2b (97％). The F genes of the randomly selected strains and hMPVgz01 were 99％ identical to each other. Sequences and phylogenetics analysis revealed that the epidemical strain in Guangzhou belonged to genotype A2b. ConclusionhMPV is prevalent in spring and summer among children in Guangzhou, and A2b is the predominant genotype.
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Objective To study the genomic molecular organization and genogroup of human metapneumovirus(hMPV) infected infants in Guangzhou of China. Methods Primers were designed on the basis of the genomic sequence of hMPV 00-1 strain(AF371337) in the GenBank, and amplify hMPV genomeby RT-PCR. The PCR-products were cloned to T vector and sequenced, the genomic nucleotide sequences were analyzed with the programs Clustal W/X, DNASTAR and MEGA4. 1. Results The cloned strainhMPVgz01 genome is 13 327 bp in length, the genome contains eight open reading frames in the order 3-N-P-M-F-M2-SH-G-L-5. The genomic sequences of hMPVgz01 strain are compared with those of hMPV in GenBank, revealed that the homology with hMPV group A ranges between 92%-97%, homology with group B is 81%, and with avian metapneumovirus group C is 71%, the highest homology is with BJ1887 strain of genogroup A2b. The N, F, G genes of hMPVgz01 strain are compared with those corresponding genes of hMPV subgroups A1, A2, B1, B2, revealed that the highest homology is also with genogroup A2b. Conclusion The complete nucleotide sequence of hMPVgz01 strain isolated from Guangzhou in China is 13 327 bp in length, GenBank accession No. is GQ153651. Comparison of the genomic sequence and three genes of hMPVgz01 strain with those corresponding sequences of hMPV show the highest homology is with genogroup A2b. Sequence and phylogenetic analysis of the hMPVgz01 strain revegled that this isolate belongs to genogroupA2b.
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Objective To prepare recombinant human adenovirus type 3 expressing Norovirus cap-sid protein gene(Noro-orf2). Methods The cDNA for Noro-orf2 was amplifed by RT-PCR from stool of in-fantile gastroenteritis and cloned into the adenovirus shuttle vector pBSE3CMV-egfp. The vector pBSE3CMV-Nor was linearized with EeoR Ⅴ and Not Ⅰ, and transformed into E. coil BJ5183 with lined edenovirus ge-nomic DNA pLasmid pBRAdv3 by Rsr Ⅱ. The identification of recombinant adenovirus plasmid pBRAdv3E3dNor was performed by PCR, enzyme digestion and DNA sequencing. Then pBRAdv3E3dNor was digested with AsiS Ⅰ and transfeeted into Hep-2 cells with LipofectAMINETM 2000 to package recombi-nant adenovirus particles. Results Noro-orf2 was successfully inserted into the shuttle vector. The recombi-nant adenoviral plasmid pBRAdv3E3dNor was generated by homologous recombination in E. coil BJ5183 and confirmed by PCR and enzyme digestion. The recombinant adenovirus was successfully packaged and puri-fied. Norovirus eapsid protein gene expression was confirmed in Hep-2 cells by immunecytochemistry assay. Conclusion The recombinant type 3 adenovirus expressing Norovirus eapsid protein gene was successfully constructed. This study laid a foundation for developing vaccine against Norovirus.