@article{mbs:/content/journal/micro/10.1099/mic.0.2008/021212-0, author = "Vidal, Maricel and Prado, Valeria and Whitlock, Gregory C. and Solari, Aldo and Torres, Alfredo G. and Vidal, Roberto M.", title = "Subtractive hybridization and identification of putative adhesins in a Shiga toxin-producing eae-negative Escherichia coli", journal= "Microbiology", year = "2008", volume = "154", number = "12", pages = "3639-3648", doi = "https://doi.org/10.1099/mic.0.2008/021212-0", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.2008/021212-0", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "EHEC, enterohaemorrhagic E. coli", keywords = "HUS, haemolytic uraemic syndrome", keywords = "A/E, attaching and effacing", keywords = "STEC, Shiga toxin-producing Escherichia coli", keywords = "HC, haemorrhagic colitis", keywords = "LEE, locus of enterocyte effacement", abstract = "Adherence to epithelial cells by specific adhesins is a characteristic of Shiga toxin-producing Escherichia coli (STEC) strains. The eae-encoded protein intimin is the main adhesin implicated in intestinal colonization in vivo. We recently showed that STEC strains isolated in Chile displayed a wide variety of adhesins; here we demonstrate that some of these STEC strains are eae-negative and still adhere to epithelial cells at a level 100-fold higher than enterohaemorrhagic E. coli (EHEC) O157 : H7 prototype strain EDL933. This phenotype is associated with the presence of adherence factors different from the intimin protein. Subtractive hybridization between EHEC EDL933 and STEC eae-negative strain 472-1 was used to identify regions implicated in adhesion. In addition to the saa gene, we identified 18 specific genes in STEC 472-1, 16 of which had nucleotide identity to Salmonella ST46 phage genes; the two remaining ones shared identity to a gene encoding a hypothetical protein of uropathogenic E. coli. The DNA sequence of the STEC 472-1 psu-int region identified five open reading frames with homology to phage genes. We constructed mutant strains in the saa gene and the psu-int region to study the participation of these genes in the adherence to epithelial cells and our results demonstrated that STECΔsaa and STECΔpsu-int mutants displayed a 10-fold decrease in adherence as compared to the STEC 472-1 wild-type strain. Overall, our results suggest that STEC strain 472-1 adheres to epithelial cells in an eae-independent matter and that saa and psu-int participate in this adhesion process.", }