| Aseptic meningitis is caused by multiple viruses infected central nervous system characterized by signs of meningeal irritation. Enteroviruses encompass approximately more than 110 serotypes, which cause more than 85% of all cases of viral meningitis. These viruses are spread from person to person by the fecal-oral and respiratory routes, and are found in the summer, late spring and fall in moderate climates. In recent years, with the deepening research, reports of aseptic meningitis caused by enterovirus have increased year by year. Meningitis can occur in individuals of any age group, but children under age of 15 are susceptible populations. Enteroviruses are spread from person to person by fecal-oral and respiratory routes, both easy ways to cause outbreaks of disease prevalent in different regions of Chinese mainland. Beyongd that, the moderate climate of Kunming, the capital city of Yunnan Province located in the southwest of China, provides benefit for the trassmission and proliferation of enteroviruses. In this study, we collected 524 clinical samples of patients suffering aseptic meningitis of one children hospital in Kunming to make etiological investigations, statistical, genetical analysis, aiming at providing important data on etiology and genetics of enteroviruses for Yunnan Province, and further supply the pathogen spectrum of enteroviruses.Enteroviruses encompass a wide spectrum of serptypes, while HEV-A and HEV-B are responsible for the most commonly identified illnesses. Therefore, to evaluate the efficiency of different (semi-)nested VP1 based-PCRs for typing enteroviruses, and to develop a rapid and sensitive molecular method for direct identification of human enteroviruse serotypes, the tests of selecting universal primers for HEV-A and HEV-B were preformed. The combination of primers for EV-A published by Iturriza-Gomara with primers for EV-B published by Leitch may have the ideal performance on typing EVs directly from clinical specimens.Then,524 clinical samples were treated as previously described. Samples were typed based on the sequencing of partial or complete VP1-encoding region, thus 16 enteroviruses serotypes were identified from clinical samples of 97 cases. The most frequent enterovirus serotypes identified were E9 (24.7%), CVB5 (23.5%), E30 (16.5%), and CVB2 (7.1%). CVA16, A9, Human coxsackievirus B4, and Human echovirus 4,6, 12,15,16,18,21,33 represented rather rare serotypes. The demographic features, clinical manifestions of patients, and labrotory findings of cases were analyzed by SPSS20.0 software between enterovirus associated with aseptic meningitis and other-virus associated with aseptic meningitis. Results showed that there were no significant differences between aseptic meningitis and other-virus associated with aseptic meningitis in demographical characteristic, clinical symptoms and labrotory findings, inferring that no specific pattern appears to be associated with this disorder.Finally, part samples were assayed for enterovirus cell culture. A155/YN/CHN/2009, A108/YN/CHN/2009, A242/YN/CHN/2009 were identified as CVB4 and CVA9. In the study, the complete genome analysis of A155/YN/CHN/2009 was performed. It had 85.1 and 83.3% nucleotide similarity with prototype strain J.V.B Benschoten in the VP1 region and the complete genome, respectively. Phylogenetic analysis of VP1 region showed that A155/YN/CHN/2009 belongs to Genotype V circulating only in mainland of China. The results of Simplot and Bootscanning analysis implicated that A155 has recombined with other HEV-B viruses. The complete genome analyses of two strains CVA9 A242/YN/CHN/2009 and Al 08/YN/CHN/2009 were performed. These two strains shared 81.3% and 80.7%,81.0% and 81.1% nucleotide similarity with prototype strain Griggs in the VP1 coding region and the complete genome, respectively. Through phylogenetic analysis and homogeneity analysis for complete VP1 gene, CV-A9 strains in this study belongs to the same genotype with other strains circulated in China. Similarity plot and bootscanning analyses showed evidence of recombination with other EV-B viruses.In summary, the main serotypes circulated in Yunnan Province in 2009 were E9、 E30、CVB5。The ideal primers combination is B-OS/B-OAS and B-IS/B-IAS, EntAF/EntARo and EntAF/Ent AFj。A155, A108, A242 were recombinant strains. The study provided important information for later research in this field... |
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