title: Temporal expression of enteropathogenic Escherichia coli virulence genes in an in vitro model of infection.
abstract: The hallmark of enteropathogenic Escherichia coli (EPEC) infection is the ability of EPEC to cause attaching and effacing (A/E) lesions on intestinal epithelium. This event is reproducible in in vitro tissue culture models of infection. We used real-time PCR to measure transcription from several locus of enterocyte effacement (LEE) operons (LEE1 to LEE5) and from bfp during a 5-h infection of HEp-2 cells with EPEC. We found that after the initial formation of A/E lesions, which occurs as early as 5 min postinfection, EPEC continues to increase transcription from LEE3 to LEE5 as well as from bfp. These levels are maximized by 3 h postinfection and remain constant throughout the course of infection. This increase in transcription from LEE3 to LEE5 occurs when LEE1 (ler) transcription is decreasing. EspA, EspB, intimin, Tir, and bundle-forming pilus expression is detectable during the entire 5-h infection. These results indicate that the EPEC genes involved in localized and intimate adherence are continually expressed after the initial stages of A/E lesion formation on host cells.
authors.affiliation: Center for Vaccine Development, School of Medicine, University of Maryland, Baltimore, MD 21201, USA.
authors.forename: Laura Q
authors.initials: LQ
authors.lastname: Leverton
authors.forename: James B
authors.initials: JB
authors.lastname: Kaper
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000502:physiology*; D016905:Gram-Negative Bacterial Infections / Q000378:metabolism*; D006801:Humans; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014774:Virulence / Q000502:physiology
chemical_list: D018829:Adhesins, Bacterial; D029968:Escherichia coli Proteins; C102051:EspA protein, E coli; C474481:EspD protein, E coli; D011956:Receptors, Cell Surface; C109287:Tir protein, E coli; C073819:eaeA protein, E coli