Type IV Pili, Transient Bacterial Aggregates, and Virulence of Enteropathogenic Escherichia coli

• Published in: Science (American Association for the Advancement of Science) Vol. 280; no. 5372; pp. 2114 - 2118
• Main Authors: Bieber, David, Ramer, Sandra W., Wu, Cheng-Yen, Murray, William J., Tobe, Toru, Fernandez, Rosemary, Schoolnik, Gary K.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 26.06.1998; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Actins; Adolescent; Adult; Agglutination; Bacteria; Bacterial Adhesion; Bacteriology; Biochemistry; Biological and medical sciences; Cell aggregates; Cell Membrane - ultrastructure; Diarrhea; Diarrhea - microbiology; Disease; Epithelial Cells - microbiology; Escherichia coli; Escherichia coli - genetics; Escherichia coli - pathogenicity; Escherichia coli - physiology; Escherichia coli - ultrastructure; Escherichia coli Infections - microbiology; Fimbriae, Bacterial - genetics; Fimbriae, Bacterial - physiology; Fimbriae, Bacterial - ultrastructure; Fundamental and applied biological sciences. Psychology; Genetic mutation; Humans; Intestinal Mucosa - microbiology; Liquids; Medical research; Microbiology; Middle Aged; Mutation; Operon; Parents; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Phenotype; Phenotypes; Plasmids; Research Design; Tumor Cells, Cultured; Virulence; Volunteerism; Volunteers; Aggregation; Escherichia coli; Virulence; Bacteria; Pilus; Mutation; Adhesion; Enterobacteriaceae
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.280.5372.2114

Type IV bundle-forming pili of enteropathogenic Escherichia coli are required for the localized adherence and autoaggregation phenotypes. Whether these pili are also required for virulence was tested in volunteers by inactivating bfpA or bfpT (perA) encoding, respectively, the pilus subunit and the bfp operon transcriptional activator. Both mutants caused significantly less diarrhea. Mutation of the bfpF nucleotide-binding domain caused increased piliation, enhanced localized adherence, and abolished the twitching motility-dispersal phase of the autoaggregation phenotype. The bfpF mutant colonized the human intestine but was about 200-fold less virulent. Thus, BfpF is required for dispersal from the bacterial aggregate and for full virulence.