title: A survey of Col plasmids in natural isolates of Escherichia coli and an investigation into the stability of Col-plasmid lineages.
abstract: A survey of colicins in the ECOR reference collection of Escherichia coli is presented. Twenty-five of the 72 ECOR strains exhibited a phenotype consistent with colicin production and E. coli isolated from human hosts were more likely to be colicinogenic than those from animal hosts. Multiple representatives of two Col plasmids, low-molecular-mass ColE1 plasmids and high-molecular-mass, conjugative ColIa plasmids were isolated from the ECOR collection and were examined with a combination of restriction fragment and Southern analysis. These data suggested that ColE1 plasmids comprise a stable (cohesive) plasmid lineage, while ColIa plasmids represent a family of distinct plasmid lineages united by the presence of the colicin Ia operon.
authors.affiliation: Department of Zoology, University of Massachusetts, Amherst 01003.
authors.forename: M A
authors.initials: MA
authors.lastname: Riley
authors.forename: D M
authors.initials: DM
authors.lastname: Gordon
mesh_terms: D003086:Bacteriocin Plasmids; D003087:Colicins / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D005838:Genotype; D010641:Phenotype
chemical_list: D003087:Colicins