Genetic Characterization Of Human Parainfluenza Virus1,2and3Circulating In Gansu And Shaanxi Provinces,2009-2011

Objective To investigate the genetic characterization of Human parainfluenza virus(HPIVs) circulating in Gansu and Shaanxi provinces of China, and acquire the baseline date of human parainfluenza virus in mainland China.Methods Seven hundred and nineteen of throat swab specimens were collected from patients with acute respiratory tract infection in Gansu and Shaanxi provinces from January,2009to December,2011. Multiplex reverse transcription polymerase chain reaction was used to screen common respiratory viral pathogens. For HPIVs-positive specimens, nested RT-PCR was used to amplify the hemagglutinin-neuraminidase (HN) protein gene. The analysis of sequence was using the professional software (Mega5, Sequencer5, and Bioedit).Results Sixty-seven of719specimens were positive for HPIVs by multiplex RT-PCR, of which39were co-infection with HPIVs and other respiratory virus. The number of HPIVs positive sample was17by nested PCR method and sequencing analysis. There were2of HPIV-1,2of HPIV-2positive samples and13of HPIV-3positive samples.2HPIV-1strains belonged to cluster B. Compared with17strains of Japanese representative strains, the homology of nucleotide and amino acid were96.3%-98.8%and96.5%-99.7%respectively. The homology of amino acid was100%among Chinese strains, Yamagata/07/2072and Yamagata/2145/09. Gansul1-62110396strain belongs to cluster A and gansu11-sl91strain belongs to cluster B of HPIV-2.Compared with18representative strains, the homology of nucleotide and amino acid were91.7%-98.4%and94.2%-98.4%respectively. The nucleotide and amino acid homology of gansul1-62110396and Oklahoma/94/USA/09were97.6%and98.4%respectively. The nucleotide homology between gansu11-s191and the Japanese isolate of4-80/04was98.4%, and the homology of amino acid was97.7%.13HPIV-3strains belonged to sub-cluster C3, the homology of nucleotide and amino acid were97.8%-99.8%and98.9%-100%respectively. Compared with the complete gene of HPIV-3strains from USA, Canada, and Australia, the homology of nucleotide and amino acid were94.0%and96.6%respectively. The homology of nucleotide between Shaanxi09-2and shaanxi10-H0091was99.4%, while the homology of nucleotide between shaanxi10-H0091andgansu11-62110372as99.3%, between shaanxi09-2and BJ/291/09was99.4%, however, there was not amino acid divergence among them.Conclusions HPIVs epidemic strains in Gansu and Shaanxi provinces were HPIV-3strains belonging to C3sub-cluster from2009to2011. It is likely that HPIV-3virus have been transmitting in Gansu and Shaanxi provinces for several years. Compared with Japanese strains, there is little sequence variation of HN gene. Thereby, HPIVs epidemic strains maybe have the characterization of geographical limitations. HPIV-1and HPIV-2strains are sporadic cases in Gansu and Shaanxi provinces.