[Genetic characterization of VP4-VP2 of two coxsackievirus A4 isolated from patients with hand, foot and mouth disease].

OBJECTIVE

To study the genetic characteristic of VP4-VP2 of Coxsackievirus A4 (CVA4) isolated from clinical specimens of patients with Hand, foot and mouth disease (HFMD) in Gansu in 2008.

METHODS

Two clinical samples were collected from HFMD patients in outpatient service, and then viral isolation was performed by inoculating RD cells. VP4-VP2 region of two viral isolates were amplified by using reverse transcription-polymerase chain reaction methods, and then the PCR products were sequenced; molecular typing was used to identify the serotype of these two viral isolates. Finally phylogenetic tree was constructed among these two Gansu viral isolates and 16 CVA4 strains downloaded from GenBank database.

RESULTS

Two Viruses were isolated from the clinical specimens collected from two HFMD patients by inoculating RD cells, and were identified as CVA4 by using molecular typing methods. The homology of the nucleotide sequences in VP4-VP2 region between the two Gansu CVA4 strains was 94.6%, and the homology of the amino acid sequences was 100%. Compared with the prototype strain of CVA4 (Strain High Point/USA/1948), the homologies of nucleotide sequences and amino acid sequences were 85.5%-85.8% and 99.3%, respectively. It revealed that two Gansu CVA4 strains lie in the independence group.

CONCLUSION

Compared with CVA4 strains isolated in Japan and Mongolia downloaded from GenBank database, two Gansu CVA4 were found to have great difference on VP4-VP2 region, and phylogenetic analysis revealed that they belong to an independence evolution lineage.