Contribution of Efa1/LifA to the adherence of enteropathogenic Escherichia coli to epithelial cells.
Enteropathogenic E. coli(EPEC) is an important diarrhoeal pathogen that induces characteristic lesions on the host intestine termed attaching and effacing (A/E) lesions. In this study we have examined the contribution of a large gene, efa1, which is present in all A/E pathogens, to the adherence phenotype of EPEC. An efa- derivative of EPEC JPN15 was constructed and this mutant was significantly less adherent to epithelial cells than the parent strain. The JPN15 efa- derivative was FAS-positive, produced EspA filaments and showed comparable levels of EspA secretion to JPN15. In addition, polyclonal antibodies raised to Efa1 partially inhibited the adherence of JPN15 to cultured epithelial cells. In further work, we showed that human and rabbit hosts infected with an A/E pathogen produced antibodies to Efa1 and we observed that the truncated form of efa1 present in EHEC O157:H7 was specific to that serotype. Generally efa1 was present in its entirety in the genomes of other A/E pathogens. Overall our data suggest that Efa1 has host cell binding activity, at least in tissue culture, and that it is produced during infection. These findings suggest that Efa1 may play a direct role in the pathogenesis of infections caused by A/E pathogens.
Department of Microbiology, Monash University, Clayton, Vic 3800, Australia.
Luminita
L
Badea
Stephen
S
Doughty
Larissa
L
Nicholls
Joan
J
Sloan
Roy M
RM
Robins-Browne
Elizabeth L
EL
Hartland
D000818:Animals; D001422:Bacterial Adhesion / Q000502:physiology*; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D001427:Bacterial Toxins; D015153:Blotting, Western; D016466:CHO Cells; D006224:Cricetinae; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology*; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D008856:Microscopy, Fluorescence; D016254:Mutagenesis, Insertional; D016133:Polymerase Chain Reaction; D014774:Virulence
D001425:Bacterial Outer Membrane Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; C404907:Efa1 protein, E coli; D029968:Escherichia coli Proteins