呼吸道合胞病毒的分型研究

目的 了解北京地区１９９０￣１９９１年和１９９７￣１９９８年两个非连续的流行年中呼吸道合胞病毒（ＲＳＶ）Ａ、Ｂ亚型和基因型的流行情况。方法 用间接免疫荧光法（ＩＩＦ）检测ＲＳＶ阳性鼻咽分泌物（ＮＰＳ）标本或ＲＳＶ分离株，划分Ａ、Ｂ亚型。根据Ｎ基因片段的限制性酶切图型将ＲＳＶ分离株分成至少６个基因型ＮＰＩ－６ＮＰＩ，３和６属于Ｂ亚型，ＮＰ２４和５属于Ａ亚型。根据ＳＨ基因片段的核苷酸序列将Ａ亚型分离株

Study on typing of Respirayory syncytial viruses

OBJECTIVE: To determine the epidemiologic patterns of subgroups A and B and genotypes of respiratory syncytial viruses (RSV) during two uncontinuously epidemic years from 1990 to 1991 and 1997 to 1998 in Beijing. METHODS: Nasopharyngeal secretion (NPS) samples of RSV positive or BSV isolates tested by indirect immunofluorescent (IIF) assay were classified into subgroups A and B. Also, isolates of RSV were divided into at least six different lineages, designated NPl-6, by restriction mapping of the N gene. NP l, 3 and 6 were given by subgroup B isolates, while NP2, 4 and 5 were given by subgroup A isolates. Strains of subgroup A were further subdivided into six lineages SHL 1-6 on the basis of the SH gene sequence. SH lineages were closely related to each other and to NP 1-6. Strains of SHL 1,3, and 4 were closely related and belonged to NP2, SHL 2 and 6 to NP4 and SHL5 to NP5. RESULTS: Of 145 RSV NPS samples from the winter 1997 to the spring 1998, 83(57.2%) were subgroup B strains, 62(42.8%) were sub-group A strains, the rate of occurrence of subgroup A to B strains was about 1:1.3. Two of 10 isolates of 1997-1998 offered by viral department of research institute of Pediatrics were subgroup A strains, whereas 8 were subgroup B strains, the rate of occurrence of subgroup A to B strains was 1:4. Eight subgroup A strains of 10 isolates from the 1990-1991 epidemic were dominant, the proportion of subgroup A to B strains was 4:1. of 10 BSV isolates in 1997-1998, all 2 subgroups A strains gave N gene fragment restriction pattern NP4, and fell into SH lineage SHL2, whereas 8 subgroup B strains all belonged to NP3. All 8 subgroup A isolates from the 1990-1991 epidemic gave pattern NP4, and fell into SHL2, while 2 subgroups B strains all belonged to NP3. The classification of subgroups A and B deduced from NP patterns was corresponded to the definition of these subgroups by monoclonal antibodies. CONCLUSIONS: These observations confirmed that subgroups A and B or multiple lineages of BSV co-circulated in Beijing, but different genomic types predominated each year. Moreover, very similar viruses were isolated up to more than 5 years ago, indicating that despite apparent diversity of the subgroup A strains, the separate lineages might be relatively stable.