title: Patterns of variations in Escherichia coli strains that produce cytolethal distending toxin.
abstract: A collection of 20 Escherichia coli strains that produce cytolethal distending toxin (CDT) were analyzed for their virulence-associated genes. All of these strains were serotyped, and multiplex PCR analysis was used to ascertain the presence of genes encoding other virulence factors, including Shiga toxin, intimin, enterohemolysin, cytotoxic necrotizing factor type 1 (CNF1) and CNF2, heat-stable toxin, and heat-labile toxin. These CDT-producing strains possessed various combinations of known virulence genes, some of which have not been noted before. Partial cdtB sequences were obtained from 10 of these strains, and their predicted CdtB sequences were compared to known E. coli CdtB sequences; some of the sequences were identical to known CdtB sequences, but two were not. PCR primers based on sequence differences between the known cdt sequences were tested for their ability to detect CDT producers and to determine CDT type. Correlations between the type of CDT produced, the presence of other virulence properties, and overall strain relatedness revealed that the CDT producers studied here can be divided into three general groups, with distinct differences in CDT type and in their complement of virulence-associated genes.
authors.affiliation: Department of Microbiology and Immunology, Chandler Medical Center, University of Kentucky, Lexington, Kentucky 40536-0298, USA. cpicket@uky.edu
authors.forename: Carol L
authors.initials: CL
authors.lastname: Pickett
authors.forename: Robert B
authors.initials: RB
authors.lastname: Lee
authors.forename: Aysegul
authors.initials: A
authors.lastname: Eyigor
authors.forename: Ben
authors.initials: B
authors.lastname: Elitzur
authors.forename: Emily M
authors.initials: EM
authors.lastname: Fox
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Strockbine
mesh_terms: D000595:Amino Acid Sequence; D001427:Bacterial Toxins / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D004926:Escherichia coli / Q000472:pathogenicity*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D019105:Random Amplified Polymorphic DNA Technique
chemical_list: D001427:Bacterial Toxins; C067044:cytolethal distending toxin