Pekka Kolehmainen1, Anu Siponen2, Teemu Smura3, Hannimari Kallio-Kokko4, Olli Vapalahti5, Anne Jääskeläinen6, Sisko Tauriainen7. 1. 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. Electronic address: pjkolehm@gmail.com. 2. Department of Virology, University of Turku, Kiinamyllynkatu 13, 20520, Turku, Finland. Electronic address: aesipo@utu.fi. 3. Department of Virology, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 3, 00290, Helsinki, Finland. Electronic address: teemu.smura@helsinki.fi. 4. Department of Virology, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 3, 00290, Helsinki, Finland; Department of Virology and Immunology, University of Helsinki and Helsinki University Hospital, HUSLAB, Topeliuksenkatu 32, 00290, Helsinki, Finland. Electronic address: hannimari.kallio-kokko@helsinki.fi. 5. Department of Virology, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 3, 00290, Helsinki, Finland; Department of Virology and Immunology, University of Helsinki and Helsinki University Hospital, HUSLAB, Topeliuksenkatu 32, 00290, Helsinki, Finland; Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Agnes Sjöbergin katu 2, 00790, Helsinki, Finland. Electronic address: olli.vapalahti@helsinki.fi. 6. Department of Virology, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 3, 00290, Helsinki, Finland; Department of Virology and Immunology, University of Helsinki and Helsinki University Hospital, HUSLAB, Topeliuksenkatu 32, 00290, Helsinki, Finland. Electronic address: anne.jaaskelainen@helsinki.fi. 7. Department of Virology, University of Turku, Kiinamyllynkatu 13, 20520, Turku, Finland. Electronic address: sisko.tauriainen@utu.fi.
Abstract
BACKGROUND: 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. OBJECTIVES: 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. STUDY DESIGN: 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. RESULTS: 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. CONCLUSION: 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.
BACKGROUND: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. OBJECTIVES: 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. STUDY DESIGN: 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. RESULTS: 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. CONCLUSION: 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.