title: Environmental regulation and colonization attributes of the long polar fimbriae (LPF) of Escherichia coli O157:H7.
abstract: The ability of Escherichia coli O157:H7 to colonize the intestinal epithelia is dependent on the expression of intimin and other adhesins. The chromosome of E. coli O157:H7 carries two loci encoding long polar fimbriae (LPF). These fimbriae mediate adherence to epithelial cells and are associated with colonization of the intestine. In order to increase our knowledge about the conditions controlling their expression and their role in colonization of an animal model, the environmental cues that promote expression of lpf genes and the role of E. coli O157:H7 LPF in intestinal colonization of lambs were investigated. We found that expression of lpf1 was regulated in response to growth phase, osmolarity, and pH; that lpf2 transcription was stimulated during late exponential growth and iron depletion; and that LPF impacts the ability of E. coli O157:H7 to persist in the intestine of infected 6-week-old lambs.
authors.affiliation: Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA. altorres@utmb.edu
authors.forename: Alfredo G
authors.initials: AG
authors.lastname: Torres
authors.forename: Lorena
authors.initials: L
authors.lastname: Milflores-Flores
authors.forename: J Gerardo
authors.initials: JG
authors.lastname: Garcia-Gallegos
authors.forename: Shilpa D
authors.initials: SD
authors.lastname: Patel
authors.forename: Angus
authors.initials: A
authors.lastname: Best
authors.forename: Roberto M
authors.initials: RM
authors.lastname: La Ragione
authors.forename: Ygnacio
authors.initials: Y
authors.lastname: Martinez-Laguna
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Woodward
mesh_terms: D000818:Animals; D003470:Culture Media / Q000378:metabolism; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D019453:Escherichia coli O157 / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D029968:Escherichia coli Proteins / Q000235:genetics; D010861:Fimbriae, Bacterial / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D006863:Hydrogen-Ion Concentration; D007422:Intestines / Q000382:microbiology; D007501:Iron / Q000378:metabolism; D009154:Mutation; D009924:Organ Culture Techniques; D009994:Osmolar Concentration; D012756:Sheep; D012757:Sheep Diseases / Q000382:microbiology*
chemical_list: D003470:Culture Media; D029968:Escherichia coli Proteins; D007501:Iron