ABSTRACT
@#Abstract: Objective To investigate the molecular characteristic and evolutionary trends of full-genome sequences of coxsackievirus A2 (CV-A2) and A5 (CV-A5) in Changsha City. Methods The CV-A2 and CV-A5 strains were isolated and detected from patients with hand, foot and mouth disease (HFMD) cases. The full-genome sequences of CV-A2 and CV-A5 strains were obtained using NGS sequencing. Homology and phylogenetic tree analysis were performed, and the recombination regions of the strains were examined by SimPlot software. Results The full-genome sequences of CV-A2 and CV-A5 strains were obtained from routine surveillance cases of HFMD in Changsha in 2019. The CV-A2 strain was named S281/Changsha/CHN/2019 with the full-genome sequence of 7 422 bp long; the CV-A5 strain was named S272/Changsha/CHN/2019 with the full-genome sequence of 7 425 bp long. Homology analysis of the isolates by comparison with the nucleic acid sequences of CV-A2 and other CV-A2 strains in China showed that the non-structural protein region shared lower similarity than that of structural protein region. The CV-A2 showed 79.20% similarity with Fleetwood strain (NC038306), showed the highest similarity 95.60% with MN419014 strain from Hubei Province. The non-structural protein 3C and 3D region shared the lowest similarity with MN419014, 90.51 and 92.06%, respectively. Phylogenetic tree analysis showed that 3C and 3D regions were located in the CV-A4 branch. Amino acid mutation sites were found in non-structural protein region, and the amino acid sequence in structural protein region was conserved. SimPlot analysis showed that genetic recombination was found in the 3C and 3D region of CV-A2 strains. The full-genome sequence of CV-A5 showed 80.7% similarity with the Swartz (AY421763) and 97.43% similarity with the strain (MH111030) from Australian. Homology analysis showed that the non-structural protein region shared lower similarity than that of structural protein region, based on full-genome of CV-A5. Phylogenetic tree analysis showed that CV-A5 and MH111030 were in the same branch, indicating that CV-A5 strain not from local. The amino acid sequence of CV-A5 strain was conserved. Conclusions The CV-A2 strain in Changsha City shared genome sequence information with CV-A4, and the CV-A5 strain was imported from abroad. Our findings are expected to understand the molecular and recombination characteristics of CV-A2 and CV-A5, provided the data of evolution and genetic features of the coxsackievirus, and interrupt disease transmission in a timely and effective manner.
ABSTRACT
Objective To analyze the complete genome sequence of a Shenzhen coxsackievirus A2 strain CVA2-SHZH13-01 and its evolution.Methods RT-PCR was used to amplify the complete genome of CVA2-SHZH13-01 strain.The PCR products were purified and sequenced to analyze their genetic character-istics.Results The complete genome of CVA2-SHZH13-01 strain was 7400 bp in length, encoding 2191 amino acids.CVA2-SHZH13-01 strain was highly similar with the novel recombinant CVA2-HK (431306) strain isolated from Hong Kong sharing the nucleotide homology of 98.3%, 98.8%, 99.0%, 99.2%, 98.8%and 98.9%in 5′UTR, P1 ( VP1 to VP4) , P2, P3, 3′UTR regions and complete genome, respec-tively.CVA2-SHZH13-01 strain was highly identical to the international standard strain CVA2-Fleetwood showing the homology of 81.6% in nucleotide sequences in P1 region, but closely associated with EV71-SHZH03 and EV71-GD2009 strains (82.8%-88.7%) in P2 and P3 regions.The phylogenetic analysis in-dicated that CVA2-SHZH13-01 strain belonged to the CVA2-HK (431306) variant.Data from analysis of amino acid in P1 region showed that there were three amino acid mutations in CVA2-SHZH13-01 strain including aa5L→F, aa666S→G and aa671T→I as compared with CVA2-HK (431306) strain.Conclusion CVA2-SHZH13-01 strain belonged to CVA2-HK (431306) variant.