Miller Raymond D, Hartl Daniel L
Department of Genetics, Washington University School of Medicine, St. Louis, MO, 63110-1095.
Evolution. 1986 Jan;40(1):1-12. doi: 10.1111/j.1558-5646.1986.tb05712.x.
A. reference collection of 72 natural isolates of Escherichia coli (the ECOR collection) has been examined with respect to eight metabolic capabilities (biotype characters) plus motility and resistance or sensitivity to five common antibiotics. Data from biotype characters were analyzed by means of unweighted pair-group cluster analysis, and the genetic variation among the strains defines three major clusters of strains with substantial variation within each cluster but greater genetic similarity of strains within a cluster than between clusters. These clusters define an infraspecific population structure in E. coli, which reflects the predominantly clonal mode of reproduction in this organism. The clusters identified by the biotype characters are in good agreement with those resulting from an analysis of 11 enzyme polymorphisms (allozymes) among the strains, and these are in good agreement with the infraspecific structure detected by factor analysis of allozyme data. The clusters of strains also differ in several genetic characteristics that are independent of those used in making the classification.
A. 已针对72株大肠杆菌自然分离株（ECOR菌库）的八项代谢能力（生物型特征）以及运动性和对五种常用抗生素的抗性或敏感性进行了检测。通过非加权配对组聚类分析对生物型特征数据进行了分析，菌株间的遗传变异确定了三个主要菌株簇，每个簇内存在显著变异，但同一簇内菌株的遗传相似性高于不同簇之间。这些簇定义了大肠杆菌的种下群体结构，这反映了该生物体主要的克隆繁殖模式。由生物型特征确定的簇与对菌株间11种酶多态性（同工酶）分析得出的簇高度一致，而这些又与通过同工酶数据分析的因子分析检测到的种下结构高度一致。菌株簇在几个遗传特征上也存在差异，这些特征与用于分类的特征无关。
