Plasmid and chromosomal elements involved in the pathogenesis of attaching and effacing Escherichia coli.
Attaching and effacing (A/E) intestinal lesions are produced by enteropathogenic Escherichia coli (EPEC), enterohemorrhagic E. coli (EHEC), and RDEC-1, a pathogen of weanling rabbits. We recently identified a chromosomal locus (eae[E. coli A/E]) which is required for A/E activity in a wild-type EPEC strain. Sequences homologous to those of an eae gene probe were detected in EPEC, RDEC-1, and EHEC isolates. We report here that the eae gene is chromosomally encoded in all EPEC and EHEC strains tested and in RDEC-1. In addition, the eae probe was found to be 100% sensitive and 98% specific in detecting E. coli of EPEC serogroups that demonstrate A/E activity. Ten percent of E. coli of EPEC serogroups that hybridized with the eae probe and produced A/E activity did not hybridize with the EAF (EPEC adherence factor) probe, a plasmid-associated diagnostic probe which is currently used to identify EPEC. In addition to A/E factors, plasmid-associated adhesins also contribute to the pathogenesis of EPEC and RDEC-1. To further investigate the role of plasmid-associated adherence, a hybrid RDEC-1-EPEC strain containing the adherence plasmid of an EPEC strain in the A/E background of RDEC-1 was constructed. This hybrid strain, unlike the parent RDEC-1 strain, produced A/E lesions on human tissue culture cells, which suggests that the EPEC adherence plasmid provides tissue specificity to the hybrid strain and that the A/E factors of RDEC-1 are not host restricted.
Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201.
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AE
Jerse
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Gicquelais
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JB
Kaper
D008841:Actin Cytoskeleton / Q000648:ultrastructure; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics*; D002478:Cells, Cultured; D002876:Chromosomes, Bacterial; D015342:DNA Probes; D004848:Epithelium / Q000382:microbiology / Q000648:ultrastructure; D004926:Escherichia coli / Q000235:genetics* / Q000472:pathogenicity*; D005798:Genes, Bacterial; D006801:Humans; D066298:In Vitro Techniques; D008871:Microvilli / Q000382:microbiology; D009693:Nucleic Acid Hybridization; D010957:Plasmids
D001426:Bacterial Proteins; D015342:DNA Probes