title: Escherichia coli and appendicitis: phenotypic characteristics of E. coli isolates from inflamed and noninflamed appendices.
abstract: Two hundred four appendiceal isolates for Escherichia coli from 146 patients with either inflamed appendices (IA) (110 patients) or noninflamed appendices (NA) (36 patients) were characterized. Strains with P fimbriae were detected in 27% of IA and 31% of NA whereas type 1C-fimbriated strains were found only in IA (13%). Four serotypes, three with K5 antigens (O18:K5, O25:K5:H1, and O75:K5:H-) and one with K1 antigen (O75:K1:H7), were isolated only from IA (20 [18%] of 110); O25:K5:H1 was the most common serotype (isolated from 11 IA [10%]). Fecal isolates from the patients with IA resembled their corresponding appendiceal isolates rather than fecal isolates from patients with NA; this finding suggests that colonization of the gut by virulent E. coli--such as a hemolysin-producing, type 1C-fimbriated, P-fimbriated O25:K5:H1 serotype--may be a prerequisite for the development of appendicitis.
authors.affiliation: Children's Hospital, University of Helsinki, Finland.
authors.forename: H
authors.initials: H
authors.lastname: Saxén
authors.forename: E
authors.initials: E
authors.lastname: Tarkka
authors.forename: P
authors.initials: P
authors.lastname: Hannikainen
authors.forename: R
authors.initials: R
authors.lastname: Nikku
authors.forename: M
authors.initials: M
authors.lastname: Rautio
authors.forename: A
authors.initials: A
authors.lastname: Siitonen
mesh_terms: D000293:Adolescent; D000942:Antigens, Bacterial / Q000032:analysis / Q000145:classification; D001064:Appendicitis / Q000382:microbiology*; D016667:Bacterial Capsules; D002648:Child; D004926:Escherichia coli / Q000145:classification* / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology*; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D010641:Phenotype; D011135:Polysaccharides, Bacterial / Q000032:analysis; D012189:Retrospective Studies; D012703:Serotyping
chemical_list: D000942:Antigens, Bacterial; D011135:Polysaccharides, Bacterial; C036962:capsular polysaccharide K1; C050673:capsular polysaccharide K5