期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1988
卷号：85
期号：20
页码：7758-7762
DOI：10.1073/pnas.85.20.7758
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Genetic relationships among 2209 isolates of Haemophilus influenzae of polysaccharide capsule serotypes a, b, c, d, e, and f were determined by analyzing electrophoretically demonstrable allelic variation at 17 chromosomal enzyme loci. We distinguished 280 electrophoretic types (ETs), representing distinctive multilocus genotypes. Genetic diversity among ETs of isolates of the same serotype was, on average, only 67% of that in the total sample, and no ETs were shared among isolates of different serotypes. Cluster analysis of the ETs revealed 2 primary phylogenetic divisions at a genetic distance of 0.66 and 12 major lineages diverging from one another at distances greater than 0.42. In general, strains of different phylogenetic lines or groups of allied lineages have characteristic cap region restriction fragment length polymorphism patterns obtained by digestion of genomic DNA with EcoRI. Strains producing serotype c, e, and f capsules have no close relationships to those of other encapsulated strains. Lineages of both serotype a and b strains occur in each primary phylogenetic division, most probably as a result of the transfer of serotype-specific sequences of the cap region between clonal lineages. Serotype a strains allied in division I with a group of abundant serotype b clones and the serotype d strains apparently are more virulent than the serotype a strains in division II, which are related to serotype b and f strains that rarely cause invasive disease.
