Prevalence Of Human Species B Adenoviruses And Analysis Of Gene Expression Pattern Of Human Species B Adenoviruses In Different Species Cells

[Objective]1.To investigate the prevalence of Human Species B adenovirus infection in hospitalized children with acute respiratory infections in Guangzhou;2.To explore gene expression pattern of human group B adenovirus HAdV-B3 and HAdV-B7 in cells of different species.[Methods]1.We collected nasopharyngeal swab specimens of children hospitalized with acute respiratory infections(ARI)in the First Affiliated Hospital of Guangzhou Medical University from May 2017 to April 2019,and extracted nucleic acids using the ABC nucleic acid extraction kit,and Detect and classify adenovirus by fluorescent real-time quantitative polymerase chain reaction(fluorescence Q-PCR),analyze the adenovirus infection of various types,and the age and season distribution of adenovirus infected children.1.The main early genes(E1,E2,E3,E4)and major late genes hexon after infectionof human embryonic kidney cells Ad293 cells and porcine kidney cells PK15 cells with SYBR? Green method were adopted(Hexon)mRNA expression was quantitatively analyzed to compare the expression patterns of the genes of HAdV-B3,HAdV-B7 and HAdV-E4.[Results]1.1)In this study,the total positive detection rate of respiratory viruses in nasopharyngeal swab specimens of 3191 hospitalized children with ARI was 35.4%(1131/3191),of which male: female = 2.17: 1(774/357),the age of the child The median is 1.00 years old(IQR,0.58-2.17);children under 5 years old account for 93.3%(1055/1131),children under 3 years old account for 83.6%(945/1131),children under 1year old 54.2%(613/1131).The positive detection rate of HAdV was 5.0%(159/3191),of which male: female = 2.31: 1(111/48),the median age of the children was 2.00 years old(IQR,1-4),and those under 5 years old Children accounted for 91.2%(145/159),children under 3 years old accounted for 69.8%(111/159),and children under 1 year old accounted for 35.8%(49/159).2)Among HAdV types,54.7%(87/159)were HAdV-B7 infections,and 37.7%(60/159)were HAdV-B3 infections.There was a statistically significant difference in the detection rate of HAdV-B3 among children of different ages(χ2 = 10.475,P = 0.022<0.05),and a difference in the detection rate of HAdV-B3 in different seasons(χ2 =9.588,P = 0.022 <0.05).Regardless of the adenovirus as a whole or each type is mainly dominated by separate infections,mixed infection with other viruses or different types of adenovirus is less.3)The overall virus detection rate and adenovirus detection rate of children exceeded 90% within 5 years of age,and the total positive detection rate of respiratory viruses showed a trend of decreasing with age(χ2 = 151.3,P <0.001).There was a statistically significant difference in the detection rate of HAdV among children of different ages(χ 2 = 38.498,P <0.001),and a difference in the detection rate of HAdV-B3 among children of different ages(χ 2 = 25.745,P <0.001),there was a statistically significant difference in the detection rate of HAdV-B7 among children ofdifferent ages(χ2 = 24.208,P <0.001).4)From May 2018 to April 2019,the overall virus,HAdV and HAdV-B7,HAdV-B55 positive detection rates were significantly different,with statistical significance.The positive rates of HAdV-B7 and HAdV-B55 from May 2018 to April2019 were significantly higher than the previous year.2.In the second part of the study,HAdV-E4 early genes E1,E2,E3,E4 and late genes Hexon gene expression changes in PK15 and Ad293 cells are consistent.The expression of HAdV-B3’s early genes E1,E2,E3,E4 in PK15 and Ad293 cells was consistent,while the expression of Hexon gene in PK15 cells was suppressed,and the plateau period appeared in 20-24 hour,while In Ad293 cells,the Hexon gene continued to rise.The expression levels of E1,E2,E3,E4 genes of HAdV-B7 in PK15 and Ad293 cells were basically the same,while the Hexon gene in PK15 cells decreased significantly 48 hours after infection.[Conclusion]1、The detection of HAdV in ARI hospitalized children in Guangzhou was mainly caused by a single virus infection,but when mixed with other viruses,RSV was the most common.Children aged 0.5 to 3 years are the key population of infection;meanwhile,HAdV can appear in all seasons,but HAdV-B3 has a high incidence in spring.Clinicians should pay attention to the detection and prevention of HAdV,and be alert to the occurrence of severe diseases.2、By analyzing the expression of HAdV-B3,HAdV-B7 early genes E1,E2,E3,E4,and late genes Hexon,we found that the expression pattern of late genes of human group B adenovirus in PK15 cells and in Ad 293 cells There are significant differences,which provide clues for the further identification of host restriction factors and lay a theoretical foundation for the construction of animal models.