title: Cyclomodulins in urosepsis strains of Escherichia coli.
abstract: Determinants of urosepsis in Escherichia coli remain incompletely defined. Cyclomodulins (CMs) are a growing functional family of toxins that hijack the eukaryotic cell cycle. Four cyclomodulin types are actually known in E. coli: cytotoxic necrotizing factors (CNFs), cycle-inhibiting factor (Cif), cytolethal distending toxins (CDTs), and the pks-encoded toxin. In the present study, the distribution of CM-encoding genes and the functionality of these toxins were investigated in 197 E. coli strains isolated from patients with community-acquired urosepsis (n = 146) and from uninfected subjects (n = 51). This distribution was analyzed in relation to the phylogenetic background, clinical origin, and antibiotic resistance of the strains. It emerged from this study that strains harboring the pks island and the cnf1 gene (i) were strongly associated with the B2 phylogroup (P, <0.001), (ii) frequently harbored both toxin-encoded genes in phylogroup B2 (33%), and (iii) were predictive of a urosepsis origin (P, <0.001 to 0.005). However, the prevalences of the pks island among phylogroup B2 strains, in contrast to those of the cnf1 gene, were not significantly different between fecal and urosepsis groups, suggesting that the pks island is more important for the colonization process and the cnf1 gene for virulence. pks- or cnf1-harboring strains were significantly associated with susceptibility to antibiotics (amoxicillin, cotrimoxazole, and quinolones [P, <0.001 to 0.043]). Otherwise, only 6% and 1% of all strains harbored the cdtB and cif genes, respectively, with no particular distribution by phylogenetic background, antimicrobial susceptibility, or clinical origin.
authors.affiliation: CHU Clermont-Ferrand, Centre de Biologie, Laboratoire de Bactériologie, Clermont-Ferrand F-63003, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Dubois
authors.forename: Julien
authors.initials: J
authors.lastname: Delmas
authors.forename: Anne
authors.initials: A
authors.lastname: Cady
authors.forename: Frédéric
authors.initials: F
authors.lastname: Robin
authors.forename: Adeline
authors.initials: A
authors.lastname: Sivignon
authors.forename: Eric
authors.initials: E
authors.lastname: Oswald
authors.forename: Richard
authors.initials: R
authors.lastname: Bonnet
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001427:Bacterial Toxins / Q000096:biosynthesis* / Q000235:genetics; D015373:Bacterial Typing Techniques; D016000:Cluster Analysis; D017714:Community-Acquired Infections / Q000382:microbiology; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D014552:Urinary Tract Infections / Q000382:microbiology; D056689:Uropathogenic Escherichia coli / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D037521:Virulence Factors / Q000096:biosynthesis* / Q000235:genetics; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D037521:Virulence Factors