Objective    To study the genomic sequence characteristics and possible origins of ente

rovirus type 71 (EV

71

) isolated from feces of patients with hand-foot-mouth disease (HFMD) from Chongqing in 2009

and compare the evolution of 3 EV

71

strains with similar genome sequences.     Methods    HFMD specimens were inoculated into human rhabdomyosarcoma (RD) cells for isolation of enteroviruses (EV). Supernatant of diseased cells was detected by RT-PCR with specific primers of EV

EV

71

and Coxsackie A16

respectively. Morphology of virus particles was observed under an electron microscope. The identified virus gene was cut into 4 fragments and amplified by RT-PCR. Complete genome sequences were detected by PCR

analyzed using bioinformatic programs

and plotted into an evolution tree.     Results    Significant diseased cells were observed in 7 out the 47 specimens from patients with HFMD that were inoculated into RD cells to isolate EV. RT-PCR showed that 3 out of the 7 specimens were positive for the specific primers of EV and EV

71

while all the samples were negative for the specific primers of Coxsackie A16. EV

71

was confirmed to be an EV

71

virus by sequencing of the PCR products of its specific primers. The virus particles in infected RD cells were round in shape with no envelope under a scanning electron microscope. The length of 3 EV

71

strains was 7 409 nt

7 406 nt

and 7 404 nt

respectively. Their homologous VP1 sequence reached over 99%. Blast analysis showed that the homology of strains isolated in Chongqing (Chongqing2-09-China and Chongqing3-09-China)was similar with that of strains isolated in Fuyang

Anhui Province (2008)

China. The homology of Chongqing1-09-China was identical with that of 984 polyprotein and 1 235 polyprotein isolated in Taiwan (2005

China). Phyiogenefie analysis showed that these strains belonged to subtype of C4 gene.     Conclusion    The newly isolated EV strains have the characteristics of enterovirus and may be of the same origin of those isolated in Fuyang County

Anhui Province (2008)

and Taiwan (2005)

China.