Genetic diversity and its dynamic variation of noroviruses causing acute diarrhea in children in Fuzhou,2009-2015

Objective To investigate the genetic diversity and explore the dynamic variation of genotypes of noroviruses causing acute diarrhea in children in Fuzhou. Methods Fecal specimens were collected from sick children aged 5 years hospitalized in Fuzhou Children Hospital due to acute diarrhea from 2009 to 2015. (real-time fluorescence quantitative-polymerase chain reaction) (Real-time PCR) was performed to identify the norovirus infection. For the positive specimens,complete viral VP1 regions and partial RdRp regions were amplified by (reverse transcription-ploymerase chain reaction) (RT-PCR) and sequenced. The online genotyping tools and phylogenetic analysis methods were used to genotype the noroviruses associated with acute diarrhea in children aged 5 years in Fuzhou. Results In 93 specimens randomly selected,91 were noroviruses positive in real-time PCR,complete VP1 from 73 noroviruses strains and partial RdRp region from 72 noroviruses strains were obtained. Complete VP1-based online genotyping revealed that 43 strains belonged to GⅡ.4_2006b,16 belonged to GⅡ.4 Syndeny_2012,10 belonged to GⅡ.3 and 2 belonged to GⅡ.4 New Orleans_2009,and 1 belonged to GⅡ.12 and GⅡ.7 respectively. Partial RdRp-based online genotyping showed that 43 strains belonged to GⅡ.P4_2006b,16 belonged to GⅡ.Pe,10 belonged to GⅡ.P12 and 1 belonged to GⅠ.P4,GⅠ.Pa and GⅡ.P21 respectively. Conclusion Combinatorial nomenclature of complete VP1 and partial RdRp regions analysis revealed that the noroviruses causing acute diarrhea in children aged 5 years in Fuzhou were genetically diverse during 2009-2015. GⅡ.P4_2006b/GⅡ.4_2006b was predominant during 2009-2012 and GⅡ.Pe/GⅡ.4 Syndeny_2012 was predominant during 2013-2015. Besides,GⅡ.P12/GⅡ.3 was the type detected consecutively in Fuzhou.