title: Representational difference analysis between Afa/Dr diffusely adhering Escherichia coli and nonpathogenic E. coli K-12.
abstract: Diffusely adhering Escherichia coli strains harboring Afa/Dr adhesins (Afa/Dr DAEC) have been associated with diarrhea and urinary tract infections (UTIs). The present work is the first extensive molecular study of a Afa/Dr DAEC strain using the representational difference analysis technique. We have searched for DNA sequences present in strain C1845, recovered from a diarrheagenic child, but absent from a nonpathogenic K-12 strain. Strain C1845 harbors part of a pathogenicity island (PAI(CFT073)) and several iron transport systems found in other E. coli pathovars. We did not find genes encoding factors known to subvert host cell proteins, such as type III secretion system or effector proteins. Several C1845-specific sequences are homologous to putative virulence genes or show no homology with known sequences, and we have analyzed their distribution among Afa/Dr and non-Afa/Dr clinical isolates and among strains from the E. coli Reference Collection. Three C1845-specific sequences (MO30, S109, and S111) have a high prevalence (77 to 80%) among Afa/Dr strains and a low prevalence (12 to 23%) among non-Afa/Dr strains. In addition, our results indicate that strain IH11128, an Afa/Dr DAEC strain recovered from a patient with a UTI, is genetically closely related to strain C1845.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 510, Faculté de Pharmacie Paris XI, 92296 Châtenay-Malabry, France.
authors.forename: Anne-Beatrice
authors.initials: AB
authors.lastname: Blanc-Potard
authors.forename: Colin
authors.initials: C
authors.lastname: Tinsley
authors.forename: Isabel
authors.initials: I
authors.lastname: Scaletsky
authors.forename: Chantal
authors.initials: C
authors.lastname: Le Bouguenec
authors.forename: Julie
authors.initials: J
authors.lastname: Guignot
authors.forename: Alain L
authors.initials: AL
authors.lastname: Servin
authors.forename: Xavier
authors.initials: X
authors.lastname: Nassif
authors.forename: Marie-Francoise
authors.initials: MF
authors.lastname: Bernet-Camard
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics; D001422:Bacterial Adhesion; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity* / Q000502:physiology; D004927:Escherichia coli Infections / Q000382:microbiology; D015723:Gene Library; D005798:Genes, Bacterial; D006801:Humans; D007501:Iron / Q000378:metabolism; D008969:Molecular Sequence Data; D013045:Species Specificity; D014552:Urinary Tract Infections / Q000382:microbiology; D014774:Virulence / Q000235:genetics
chemical_list: D018829:Adhesins, Bacterial; D004269:DNA, Bacterial; D007501:Iron