Cell-detaching Escherichia coli (CDEC) strains from children with diarrhea: Identification of a protein with toxigenic activity.
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 alphahly, 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.
Abduch Fábrega
Vanessa Louise
VL
Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, Rua Botucatu 862, 3 andar, 04023-062 São Paulo, SP, Brazil.
Piantino Ferreira
Antonio José
AJ
Reis da Silva Patrício
Francy
F
Brinkley
Carl
C
Affonso Scaletsky
Isabel Cristina
IC
D000818:Animals; D001427:Bacterial Toxins / Q000302:isolation & purification / Q000633:toxicity*; D001483:Base Sequence; D016022:Case-Control Studies; D002648:Child; D015342:DNA Probes; D003967:Diarrhea / Q000382:microbiology* / Q000473:pathology; D004351:Drug Resistance; D004768:Enterotoxins / Q000032:analysis / Q000378:metabolism; D004926:Escherichia coli / Q000145:classification / Q000302:isolation & purification / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology* / Q000473:pathology; D029968:Escherichia coli Proteins / Q000302:isolation & purification / Q000378:metabolism / Q000633:toxicity*; D006801:Humans; D011817:Rabbits; D012703:Serotyping / Q000379:methods
D001427:Bacterial Toxins; D015342:DNA Probes; D004768:Enterotoxins; D029968:Escherichia coli Proteins