Molecular characterization of foot-and-mouth disease virus in Hong Kong during 2001-2002.

Most of the molecular epidemiological studies of foot-and-mouth disease virus (FMDV) are based on comparison of VP1 gene sequence. In this report, The nucleotide sequences of the VP1 coding region of FMDV type O strains O/HKN/3/01, O/HKN/5/01, O/HKN/12/01, O/HKN/7/02 and O/HKN/10/02, isolated from the disease outbreak that occurred in Hong Kong Special Administrative Region (Hong Kong SAR) of China during 2001-2002, were determined and compared with the sequences of other FMDVs. The results revealed that the VP1 gene of the five isolates had the same nucleotide (nt) sequences (639 nt), coding for 213 amino acids, and no changes were found either at the critical amino acid sites 144 (Val), 148 (Leu), 154 (Lys) and 208 (Pro) within the VP1 protein epitope (amino acids 140-160, 200-213), or in the amino acids 145-147 comprising the arginine-glycine-aspartic acid (RGD) sequence that is involved in the adsorption of virus to host cell. Analysis of the VP1 gene nucleotide sequence revealed that the five isolates examined were most closely related to FMDVs found in Hong Kong from 1991 to 1999 and Taiwan in 1997. Furthermore, although the critical amino acids on the antigen epitope of the prevalent Hong Kong isolates and the serotype O vaccine strain, O1/Manisa/Turkey/69, showed relative conservativeness, they were distantly related genetically, which showed that there existed variation between the prevalent Hong Kong FMDV strains and the vaccine strain.