Genetic characterization of human bocavirus among children with severe acute respiratory infection in China

Abstract

Objectives: To investigate the genetic character of Human bocavirus (HBoV) among children with severe acute respiratory infection (SARI) in China.

Methods: We screened 993 respiratory samples for HBoV by PCR among hospitalized children with SARI between September 2007 and March 2014. Four of HBoV1 samples were selected for complete genomes analysis by next-generation sequencing.

Results: The results show that 200 (20.1%) out of 993 samples were HBoV-positive, most of these HBoV belong to HBoV1 subtype (n = 197), HBoV2 (n = 1) and HBoV3 (n = 2) were also detected. Fifty (5.04%) of 993 SARI patient were detected as HBoV-positive only. Four HBoV1 genomes in this study were conserved and showed no significant difference among the nucleotide diversity from different regions. Analyses of evolutionary rates showed that NS1 exhibited the highest degree of conservation while the VP1 gene exhibited the fastest rate of evolution at 4.20 × 10(-4) substitutions/site/year. The nucleotide deletions and substitutions occurred in NP1 and VP1 represented novel molecular signatures enabling subtype differentiation between HBoVs.

Conclusions: We described some new characteristics in the epidemiology of HBoV among children with SARI, these data will significantly expand the current knowledge of HBoV epidemic and genomic characterization among children with SARI.

Keywords: Evolutionary rate; Genome; Human bocavirus; Phylogenetic analysis; Severe acute respiratory infection.