Cell-detaching Escherichia coli (CDEC) strains from children with diarrhea: identification of a protein with toxigenic activity

• Published in: FEMS microbiology letters Vol. 217; no. 2; pp. 191 - 197
• Main Authors: Abduch Fábrega, Vanessa Louise, Piantino Ferreira, Antonio José, Reis da Silva Patrı́cio, Francy, Brinkley, Carl, Affonso Scaletsky, Isabel Cristina
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 17-12-2002
• Subjects: Cell-detaching Escherichia coli; Diarrhea; Toxin; Virulence property; Cell-detaching Escherichia coli; Diarrhea; Toxin; Virulence property
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1016/S0378-1097(02)01071-6

Twenty-four strains of cell-detaching
Escherichia coli (CDEC) isolated from stool specimens in different cities in Brazil were examined for virulence properties. Aerobactin production and multiple antibiotic resistance were observed in most of the isolates. In hybridization studies, the α
hly,
pap, and
cnf sequences, common properties of this category of
E. coli, were found in a minority of isolates. Half of the CDEC isolates had enteroaggregative DNA sequences (
pet,
astA,
aggA), six strains carried the
shet1 gene, nine strains carried the
daaC sequence, and one strain carried the
stp gene. Thirteen strains induced fluid accumulation in the rabbit intestinal loop assay. Supernatant filtrate of one of those strains, which did not hybridize with any of the toxin probes tested, induced destructive lesions in the rabbit ileal loop and enterotoxic activity in the Ussing chamber. A 12-kDa protein purified by 60% ammonium sulfate precipitation of the supernatant filtrate demonstrated a toxigenic effect that was inhibited by the anti-12-kDa protein antiserum.