ABSTRACT
Objective To analyze the genetic characterization of norovirus isolated in an outbreak of gastroenteritis in Jiangsu province.Methods Extracted viral RNA from the swab samples of cases of acute gastroenteritis outbreak in Jiangsu province on December 16-27,2016 was reversely transcribed to cDNA,and partial RNA-dependent RNA polymerase sequence and complete capsid sequence (VP1) were amplified by RT-PCR.Amplification products were sequenced for the analysis of genetic characteristics.Results Based on sequence alignment,the variant shared a high level of identity with the strain G Ⅱ.g isolated in Spain and Finland (98.7％) in the RNA-dependent RNA polymerase region,and with the strain G Ⅱ.1 isolated in American (99.4％) in the VP1.The recombination was determined by using software Simplot,and the breakpoint of recombination was located in the ORF 1/2 overlap region at position 5 106 of VP 1.The result of amino acids alignment in capsid region showed that there were no mutations in the amino acids of the predicted epitopes and receptor binding site Ⅰ-Ⅲ,but a unique amino acid change was detected at position 132 (N-S).Conclusion The norovirus isolated in the outbreak of gastroenteritis in Jiangsu province was a rare recombinant norovirus variant G Ⅱ.g-G Ⅱ.1.
ABSTRACT
Objective To analyze the genetic characterization of norovirus isolated in an outbreak of gastroenteritis in Jiangsu province.Methods Extracted viral RNA from the swab samples of cases of acute gastroenteritis outbreak in Jiangsu province on December 16-27,2016 was reversely transcribed to cDNA,and partial RNA-dependent RNA polymerase sequence and complete capsid sequence (VP1) were amplified by RT-PCR.Amplification products were sequenced for the analysis of genetic characteristics.Results Based on sequence alignment,the variant shared a high level of identity with the strain G Ⅱ.g isolated in Spain and Finland (98.7％) in the RNA-dependent RNA polymerase region,and with the strain G Ⅱ.1 isolated in American (99.4％) in the VP1.The recombination was determined by using software Simplot,and the breakpoint of recombination was located in the ORF 1/2 overlap region at position 5 106 of VP 1.The result of amino acids alignment in capsid region showed that there were no mutations in the amino acids of the predicted epitopes and receptor binding site Ⅰ-Ⅲ,but a unique amino acid change was detected at position 132 (N-S).Conclusion The norovirus isolated in the outbreak of gastroenteritis in Jiangsu province was a rare recombinant norovirus variant G Ⅱ.g-G Ⅱ.1.
ABSTRACT
Objective To investigate the prevalent situations of norovirus infection and genotype distributions in 2014 in Suzhou area .Methods A total of 322 fecal specimens were collected from infants with suspected viral diarrhea at Children′s Hospital of Soochow University in 2014 .Norovirus genogroupⅠ and Ⅱ was detected by reverse transcription (RT )‐polymerase chain reaction (PCR) ,In an effort to identify norovirus genotypes , RNA dependent RNA polymerase region (region A ) and capsid region (region C) segment of some samples positive for norovirus was amplified by RT‐PCR .Comprehensive molecular characteristics of norovirus were obtained by sequence analysis of the same samples in different regions .Results Among 322 fecal specimens ,67 cases were positive for norovirus of G Ⅱ group ,and norovirus of GⅠ group was not found .The genetic fragments of region A was successfully detected in 42 strains .Among all 42 specimens ,there were 35 GⅡ .e strains ,3 GⅡ .7 strains ,2 GⅡ .17 strains and 2 GⅡ .12 strains .The genetic fragments of region C was successfully detected in 53 strains .Among these 53 specimens ,there were 44 GⅡ .4‐2012Sydney strains ,4 GⅡ .6 strains ,2 GⅡ .17 strains ,2 GⅡ .3 strains and 1 GⅡ .2 strain .Conclusions It′s indicated that G Ⅱ .4‐2012Sydney is the main genotype of norovirus causing viral diarrhea in Suzhou ,and other genotypes including the new GⅡ .17 variant ,GⅡ . 7/GⅡ .6 and GⅡ .12/GⅡ .3 recombinant strains also exist .
ABSTRACT
ObjectiveTo investigate norovirus infection status and indentify its epidemiological characteristics and genotype distribution in infantile viral diarrhea in Jiangsu.MethodsFour hundred and ninety-eight fecal specimens of infantile virus diarrhea cases were collected from Suzhou Children's hospital and Nanjing Children's hospital in 2010.Norovirus genegroup were detected by real-time RT-PCR,and genetype were determined by sequence analysis.Results Among all fecal specimens,2 (0.4％) cases were positive for norovirus G Ⅰ,and 190 (38％) cases for G Ⅱ.Nucleotide sequence analysis revealed that in the 2 samples for G Ⅰ,one strain was G Ⅰ 1 and another was G Ⅰ 3.Twenty-one strains were belonged to G Ⅱ 4 and 2 strains were G Ⅱ 3 in the 23 samples for G Ⅱ.ConclusionAs one of the most important pathogens causing infantile viral diarrhea in Jiangsu province,subtype G Ⅱ 4 was the main epidemic strain of norovirus,meanwhile other genotypes also existed.