广东登革Ⅰ型病毒株变异性的初步研究

Objective　To study the variation of Guangdong dengue-1 virusstrains. Methods　Partial nucleotide fragments in E/NS1 gene junction of 2degue-1 isolates(LD-25, LD-26) and 1 positive sera sample (95-142) of Guangdong provincecollected in different years, were amplified by RT-PCR and sequenced. The 240bp sequencesof the above-mentioned fragments were compared with those of other well-characterizeddengue-1 strains. A divergence of 6% between the nucleotide sequences was taken as anindication for dengue virus subtype classification. Results　LD-25 and LD-36 or 95-142 may belong to two differentsubtypes. Dengue strains of LD-25 (1985), Thai(1980) and Taiwan of China(1987,1988) couldfall into the same subtype in the light of their sequence homology ranging from 97.1% to98.8%. The sequence homology among LD-36(1991), 95-142(1995), Philippine(1988) and threeother dengue-1 virus strains ranged from 97.5% to 100%, indicating that they belonged toanother subtype of dengue virus. Possible source of infection of these dengue virusstrains is discussed. Conclusion　Guangdong dengue viruses may have not only one source.

Preliminary study on variation of Guangdong dengue-1 virus strains

Objective To study the variation of Guangdong dengue 1 virus strains. Methods Partial nucleotide fragments in E/NS1 gene junction of 2 degue 1 isolates(LD 25, LD 26) and 1 positive sera sample (95 142) of Guangdong province collected in different years, were amplified by RT PCR and sequenced. The 240bp sequences of the above mentioned fragments were compared with those of other well characterized dengue 1 strains. A divergence of 6% between the nucleotide sequences was taken as an indication for dengue virus subtype classification. Results LD 25 and LD 36 or 95 142 may belong to two different subtypes. Dengue strains of LD 25 (1985), Thai(1980) and Taiwan of China(1987,1988) could fall into the same subtype in the light of their sequence homology ranging from 97.1% to 98.8%. The sequence homology among LD 36(1991), 95 142(1995), Philippine(1988) and three other dengue 1 virus strains ranged from 97.5% to 100%, indicating that they belonged to another subtype of dengue virus. Possible source of infection of these dengue virus strains is discussed. Conclusion Guangdong dengue viruses may have not only one source.