Identification And Hexon Genetic Phylogene-Tic Analysis Of Human Adenovirus Isolated In Nanjing, Hunan, And Lanzhou

Research Objective1.To confirm the molecular epidemiological characteristics of Hunan Adenovirus (HAdV) in children with acute respiratory infections (ARTI) in Nanjing, Hunan and Lanzhou from2009to2012. This is provide theoretical data for the prevention and treatment of acute respiratory infections.2.To identify the positive strain in Nanjing, Hunan and Lanzhou, and learn Hexon gene structure of Adenovirus in-depth. We analyzed of molecular evolutionary features, which is help us to understand the taxonomic status and evolutionary relationships of the HAdV family. To provide a theoretical basis and theoretical basis for future research about HAdV, such as development of adenovirus vectors, vaccines and anti-adenovirus drugs.Subjects and Study Design1.3530respiratory samples (nasopharyngeal aspirates and nasopharyngeal swabs) were collected from Nanjing, Hunan (August2010-July2012) from Lanzhou (November2009-December2011).2.3530specimens were detected for HAdV general nested PCR (Nest-PCR). 3.382specimens were randomly selected from the positive for HAdV, and cultured in Hela cells,293T and A549cells.The specimens which appeared typical cytopathic effect were collected the cell supernatant for isolation and identification of HAdV strains, and serum typing identified.39identified HAdV strains were sequenced for the whole genome of Hexon gene.We made alignment analysis and aligned them with the published Hexon complete genome in the GenBank.Results1. In the research, HAdV infection was identified in253patients (19.6%) in Nanjing children’s hospital and164patients (14.0%) in the People’s Hospital of Hunan province from2010to2012.The positive rate of HAdV was12.3%(132/1069) in the First Hospital of Lanzhou University from2009-2011.2. We isolated39HAdV strains from382adenovirus-positive specimens which were randomly selected.39HAdV strains contain25from Nanjing,9from Hunan, and5from Lanzhou. The type of39were6HAdV-1,6HAdV-2,9HAdV-3,1HAdV-4,3HAdV-5,13HAdV-7,1HAdV-21.3. The Hexon gene structure of39HAdV strains were analyed.The complete length of the Hexon were approximately2800bp, encoding900amino acids. We compare the homologies between the7different serotypes and reference strains in GenBank.The homologies were68%-100%, the differences were0%-37.4%of the HAdV1-5, HAdV-7and HAdV-21from Nanjing; The nucleotide sequence homologies63.1%-100%,the difference were0%-34.2%between Lanzhou isolates and GenBank reference strains; Hunan isolates and the reference strains homologies were69.2%-100%, the difference were0%-35.5%.Conclusions1. The detection rate of HAdV were all greater than10%(19.6%,14.0%.12.3%) in Nanjing, Hunan, and Lanzhou for two consecutive years associated virus detection caused by acute respiratory infections in infants and young children. HAdV is the second virus lead to the ARTI and just follow as the RSV (Respiratory Syneytial Virus). It is a warning that HAdV is major pathogens of respiratory tract infections in children in this three regions of China.2. HAdV infection can occur throughout the year, no significant seasonal differences, most infants and children were below5years old. The major epidemic strains in Nanjing, Hunan and Lanzhou were mainly HAdV-3and HAdV-7and other rare serotypes HAdV-1, HAdV-2, HAdV-5, HAdV-6HAdV-11, HAdV-31, HAdV-57also has detected but low detection rate.3.The type of the isolated HAdV strain aslo were mainly HAdV-7type of group B,33.3%(13/39) of the total isolates, the second one is HAdV-3, HAdV-21isolated rare was low. The type of group C HAdV-1, HAdV-2, HAdV-5is also more common but just one isolate belong to HAdV-4of group E.4. Make comparison about the Hexon gene of HAdV between39isolates and thereference strains in GenBank.We found that they were high homologies eath other, but there are also individual nucleotide and amino acid substitutions and variation. All these substitutions and variation mainly exists in the the neutralizing antigen Hexon protein conserved region, hypervariable region does not appear significant variation. So our study is very useful for adenoviral vectors for future research and development of HAdV vaccines and anti-adenovirus drugs.