title: Bacterial macroscopic rope-like fibers with cytopathic and adhesive properties.
abstract: We present a body of ultrastructural, biochemical, and genetic evidence that demonstrates the oligomerization of virulence-associated autotransporter proteins EspC or EspP produced by deadly human pathogens enterohemorrhagic and enteropathogenic Escherichia coli into novel macroscopic rope-like structures (>1 cm long). The rope-like structures showed high aggregation and insolubility, stability to anionic detergents and high temperature, and binding to Congo Red and thioflavin T dyes. These are properties also exhibited by human amyloidogenic proteins. These macroscopic ropes were not observed in cultures of nonpathogenic Escherichia coli or isogenic espP or espC deletion mutants of enterohemorrhagic or enteropathogenic Escherichia coli but were produced by an Escherichia coli K-12 strain carrying a plasmid expressing espP. Purified recombinant EspP monomers were able to self-assemble into macroscopic ropes upon incubation, suggesting that no other protein was required for assembly. The ropes bound to and showed cytopathic effects on cultured epithelial cells, served as a substratum for bacterial adherence and biofilm formation, and protected bacteria from antimicrobial compounds. We hypothesize that these ropes play a biologically significant role in the survival and pathogenic scheme of these organisms.
authors.affiliation: Laboratorio de Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Delegación Cuauhtémoc, México D.F. 06720, México.
authors.forename: Juan
authors.initials: J
authors.lastname: Xicohtencatl-Cortes
authors.forename: Zeus
authors.initials: Z
authors.lastname: Saldaña
authors.forename: Wanyin
authors.initials: W
authors.lastname: Deng
authors.forename: Elsa
authors.initials: E
authors.lastname: Castañeda
authors.forename: Enrique
authors.initials: E
authors.lastname: Freer
authors.forename: Phil I
authors.initials: PI
authors.lastname: Tarr
authors.forename: B Brett
authors.initials: BB
authors.lastname: Finlay
authors.forename: José Luis
authors.initials: JL
authors.lastname: Puente
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Girón
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001422:Bacterial Adhesion; D024881:Drug Resistance, Bacterial / Q000187:drug effects; D054324:Enterohemorrhagic Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000472:pathogenicity; D054308:Enteropathogenic Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000472:pathogenicity; D004847:Epithelial Cells / Q000378:metabolism / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000648:ultrastructure; D006367:HeLa Cells; D006801:Humans; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000648:ultrastructure
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; C102541:EspC protein, E coli; C107189:EspP protein, E coli; D012697:Serine Endopeptidases