2013—2015年安庆地区腺病毒流行株型别鉴定及六邻体基因特征分析

Identification of adenovirus epidemic strains and analysis of hexon gene characteristics in Anqing area from 2013 to 2015

目的 了解引起安庆地区急性呼吸道感染的人类腺病毒( HAdv)流行株型别特点及编码六邻体蛋白基因及氨基酸残基的变异情况.方法 收集2013—2015年间流感监测哨点596份急性呼吸道感染患儿咽拭子,real-time PCR腺病毒核酸检测试剂盒进行检测,阳性标本进行Hep细胞病毒分离,对病毒分离成功样本进行六邻体蛋白基因( hexon gene) PCR扩增、测序并将序列与Gen-Bank发表的序列进行同源比对和进化树分析.结果 HAdv阳性标本68份,阳性率为11. 4% .病毒分离成功34株,其中,HAdv-3型为9株占26. 5% ;HAdv-7型为12株占35. 3% ;HAdv-14型为12株占35. 3% ;HAdv-55型为1株占2. 9% . 9株HAdv-3型分离株与KX384958亲缘关系最近,为99. 8% ~100% ,与其他株相比较氨基酸残基的变异主要有 3 个;12 株 HAdv-7 型分离株与 KX897164 和KU361344亲缘关系最近,为99. 8% ~100% ,与其他株相比较氨基酸残基的变异主要有7 个;12 株HAdv-14型分离株与JF420883亲缘关系最近,为99. 6% ~99. 9% ,与其他株相比较氨基酸残基的变异主要有3个;1株HAdv-55型分离株与KP279748和KX289874亲缘关系较近,核苷酸和氨基酸的同源性为100% .在这几个型别的研究株中HAdv-7 型变异最大,其次为 HAdv-14 型.结论 2013—2015年,引起安庆地区急性呼吸道感染的腺病毒流行株主要为HAdv-3型、HAdv-7型、HAdv-14型,同时存在少量HAdv-55型. HAdv-55型分离株六邻体基因稳定,没有出现变异.而HAdv-3型、HAdv-7型、HAdv-14型型别之间,核苷酸和氨基酸均发生不同程度的变异.在抗原决定簇HVR1、HVR2 和HVR7区存在氨基酸的变异.

Objective To investigate the characteristics of human adenovirus ( HAdv) epidemic strains and the variations of hexon protein and amino acid residues in acute respiratory infections in Anqing. Methods A total of 596 throat swab samples of children with acute respiratory infections were collected from influenza surveillance sites between 2013 and 2015 and detected with real-time fluorescent PCR adeno-virus nucleic acid test kit. Hep cells were used to separate viruses from positive samples. PCR amplification of hexon gene and sequencing analysis were conducted. Homologous alignment and phylogenetic tree analysis were performed between the obtained sequences and those published in GenBank. Results HAdv-positive samples accounted for 11. 4% (68). Thirty-four viruses were successfully isolated, including nine HAdv-3 (26. 5% ), 12 HAdv-7 (35. 3% ), 12 HAdv-14 (35. 3% ) and one HAdv-55 (2. 9% ). The 9 strains of HAdv-3 had a close genetic relationship with KX384958, sharing a homology of 99. 8%-100% . Three muta-tions in main amino acid residues were found in them as compared with reference strains. The 12 strains of HAdv-7 were genetically related to KX897164 and KU361344 with a homology ranging from 99. 8% to 100% and had seven major amino acid residue mutations in comparison to reference strains. The 12 strains of HAdv-14 were highly similar to JF420883 with a homology of 99. 6%-99. 9% , and possessed three major variations in amino acid residues in comparison to reference strains. The HAdv-55 strain was closely related to KP279748 and KX289874, showing a homology of 100% in both nucleotide and amino acid sequences. HAdv-7 strains had the greatest variations, followed by HAdv-14 strains. Conclusion From 2013 to 2015, the epidemic adenovirus strains causing acute respiratory infections in Anqing area were mainly HAdv-3, HAdv-7 and HAdv-14 with a small number of HAdv-55. The hexon genes of HAdv-55 strains were stable and no variation occurred. However, HAdv-3, HAdv-7 and HAdv-14 strains all had some variations in nu-cleotides and amino acids. Amino acid variations in the antigenic determinants of HVR1, HVR2 and HVR7 regions were detected.