Kolehmainen Pekka, Siponen Anu, Smura Teemu, Kallio-Kokko Hannimari, Vapalahti Olli, Jääskeläinen Anne, Tauriainen Sisko
Department of Virology, University of Turku, Kiinamyllynkatu 13, 20520, Turku, Finland; Department of Virology, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 3, 00290, Helsinki, Finland.
Department of Virology, University of Turku, Kiinamyllynkatu 13, 20520, Turku, Finland.
J Clin Virol. 2017 Mar;88:1-7. doi: 10.1016/j.jcv.2017.01.001. Epub 2017 Jan 3.
Human parechoviruses (HPeVs) (family Picornaviridae), are common pathogens in young children. Despite their high prevalence, research on their genetic identity, diversity and evolution have remained scarce.
Complete coding regions of three previously reported HPeV-4 isolates from Finnish children with sepsis-like disease were sequenced in order to elucidate the phylogenetic relationships and potential recombination events during the evolution of these isolates.
The isolated viruses were sequenced and aligned with all HPeV complete genome sequences available in GenBank. Phylogenetic trees were constructed and similarity plot and bootscanning methods were used for recombination analysis.
The three HPeV-4 isolates had 99.8% nucleotide sequence similarity. The phylogenetic analysis indicated that capsid-encoding sequences of these HPeV-4 isolates were closely related to other HPeV-4 strains (80.7-94.7% nucleotide similarity), whereas their non-structural region genes 2A to 3C clustered together with several HPeV-1 and HPeV-3 strains, in addition to the HPeV-4 strain K251176-02 (isolated 2002 in the Netherlands), but not with other HPeV-4 strains. However, in 3D-encoding sequence the Finnish HPeV-4 isolates did not cluster with the strain HPeV-4/K251176-02, but instead, formed a distinct group together with several HPeV-1 and HPeV-3 strains. Similarity plot and Bootscan analyses further confirmed intertypic recombination events in the evolution of the Finnish HPeV-4 isolates.
Intertypic recombination event(s) have occurred during the evolution of HPeV-4 isolates from children with sepsis-like disease. However, due to the low number of parechovirus complete genomes available, the precise recombination partners could not be detected. The results suggest frequent intratypic recombination among parechoviruses.
人细小病毒（HPeV）（微小核糖核酸病毒科）是幼儿常见的病原体。尽管其感染率很高，但关于其基因特征、多样性和进化的研究仍然很少。
对之前报道的3株来自患有败血症样疾病的芬兰儿童的HPeV - 4分离株的完整编码区进行测序，以阐明这些分离株在进化过程中的系统发育关系和潜在的重组事件。
对分离出的病毒进行测序，并与GenBank中所有可用的HPeV完整基因组序列进行比对。构建系统发育树，并使用相似性图和bootscanning方法进行重组分析。
这3株HPeV - 4分离株的核苷酸序列相似性为99.8%。系统发育分析表明，这些HPeV - 4分离株的衣壳编码序列与其他HPeV - 4毒株密切相关（核苷酸相似性为80.7 - 94.7%），而它们的非结构区基因2A至3C除了与荷兰2002年分离出的HPeV - 4毒株K251176 - 02外，还与几株HPeV - 1和HPeV - 3毒株聚集在一起，但不与其他HPeV - 4毒株聚集。然而，在3D编码序列中，芬兰的HPeV - 4分离株没有与HPeV - 4/K251176 - 02毒株聚集在一起，而是与几株HPeV - 1和HPeV - 3毒株形成了一个独特的组。相似性图和Bootscan分析进一步证实了芬兰HPeV - 4分离株进化过程中的型间重组事件。
患有败血症样疾病儿童的HPeV - 4分离株在进化过程中发生了型间重组事件。然而，由于可用的细小病毒完整基因组数量较少，无法检测到精确的重组伙伴。结果表明细小病毒之间存在频繁的型内重组。
