title: Virulence-associated characteristics of Escherichia coli in urinary tract infection: a statistical analysis with special attention to type 1C fimbriation.
abstract: The relative virulence (defined as odds ratio) associated with different O and K antigens, adhesins and hemolysin production of Escherichia coli strains was assessed by separate and multivariate logistic regression analyses comparing 383 strains isolated from urine of adults with a urinary tract infection with 287 fecal strains from healthy adults; special interest was paid to evaluating the role of type 1C fimbriation. Type 1C fimbriae, found on 14% of UTI and 7% of fecal strains, were associated with O groups O2, O6, O18, and O75, with capsular type K5, with mannose-resistant (both P and non-P) adhesins, and with hemolysin production. In separate analyses, O8 (odds ratio 5.9) and O75 (9.2), capsular types other than K1 (1.9-2.1), P (2.9) and non-P mannose-resistant (17.4) adhesins, and hemolysin production (3.1) were each associated with high relative virulence compared to O1, Rough, and K1 phenotypes or lack of mannose-resistant adhesins or hemolysin. All these virulence effects were independent of type 1C fimbriation. In multivariate analysis, joint variation between factors decreased the apparent virulence-promoting effect of type 1C fimbriae, O6 antigen and hemolysin but increased that of other adhesins. Especially high relative virulence (odds ratio 404.2) was associated with the combination of O75:K5:non-P mannose-resistant adhesin identified on seven UTI but no fecal strains.
authors.affiliation: National Public Health Institute, Helsinki, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Siitonen
authors.forename: R
authors.initials: R
authors.lastname: Martikainen
authors.forename: R
authors.initials: R
authors.lastname: Ikäheimo
authors.forename: J
authors.initials: J
authors.lastname: Palmgren
authors.forename: P H
authors.initials: PH
authors.lastname: Mäkelä
mesh_terms: D000328:Adult; D000942:Antigens, Bacterial; D000954:Antigens, Surface / Q000032:analysis; D015815:Cell Adhesion Molecules / Q000032:analysis; D004926:Escherichia coli / Q000145:classification / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000145:classification / Q000453:epidemiology / Q000382:microbiology*; D010861:Fimbriae, Bacterial; D005387:Finland / Q000453:epidemiology; D006460:Hemolysin Proteins / Q000032:analysis; D006801:Humans; D015999:Multivariate Analysis; D019081:O Antigens; D016017:Odds Ratio; D011135:Polysaccharides, Bacterial / Q000032:analysis; D013045:Species Specificity; D014552:Urinary Tract Infections / Q000453:epidemiology / Q000382:microbiology*; D014774:Virulence
chemical_list: D000942:Antigens, Bacterial; D000954:Antigens, Surface; D015815:Cell Adhesion Molecules; D006460:Hemolysin Proteins; C030659:K antigens; D019081:O Antigens; D011135:Polysaccharides, Bacterial