title: Colonization factors of enterotoxigenic Escherichia coli isolated from children in north India.
abstract: Colonization factor antigens (CFAs) mediate attachment of enterotoxigenic Escherichia coli (ETEC) to the intestinal mucosa and induce protective immunity against ETEC diarrhea. ETEC strains (n = 111) isolated from North Indian children from 1985 to 1989 were examined for CFAs and putative colonization factors (PCFs). CFA/IV was the most common factor (26%), followed by coli surface antigen 17 (CS17) (19%), CFA/I (14%), PCFO166 (7%), and CFA/II (5%), while 24% of the isolates were negative for CFAs and PCFs. Among the strains producing heat-stable and heat-labile toxin (ST+LT+ strains), the STaI gene was strongly associated with the absence of known CFAs and PCFs, making the STaI+LT+ isolates an interesting target for the identification of previously undescribed factors. Repetitive sequence--based polymerase chain reaction revealed that the CS17+ strains, although clonally related, represented endemically circulating strains with a diversity greater than that of the CFA/I+ strains, which showed a substantial clonal clustering.
authors.affiliation: Center for International Health, Haukeland Hospital, University of Bergen, Norway.
authors.forename: H
authors.initials: H
authors.lastname: Sommerfelt
authors.forename: H
authors.initials: H
authors.lastname: Steinsland
authors.forename: H M
authors.initials: HM
authors.lastname: Grewal
authors.forename: G I
authors.initials: GI
authors.lastname: Viboud
authors.forename: N
authors.initials: N
authors.lastname: Bhandari
authors.forename: W
authors.initials: W
authors.lastname: Gaastra
authors.forename: A M
authors.initials: AM
authors.lastname: Svennerholm
authors.forename: M K
authors.initials: MK
authors.lastname: Bhan
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins / Q000032:analysis / Q000235:genetics; D001428:Bacterial Vaccines / Q000276:immunology; D002675:Child, Preschool; D004768:Enterotoxins / Q000032:analysis / Q000235:genetics; D004926:Escherichia coli / Q000472:pathogenicity*; D029968:Escherichia coli Proteins; D036781:Fimbriae Proteins; D005838:Genotype; D006801:Humans; D007223:Infant; D016133:Polymerase Chain Reaction
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D001428:Bacterial Vaccines; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C022924:colonization factor antigens; C034151:heat stable toxin (E coli); D036781:Fimbriae Proteins; C027538:heat-labile enterotoxin, E coli