Characterization of enteroaggregative Escherichia coli isolates.
Forty enteraggregative Escherichia coli (EAggEC) previously characterized by their ability to adhere to HEp-2 cells or/and their hybridization with the 1-kb EAggEC DNA probe were investigated for the presence of adherence factors and heat-stable enterotoxin (EAST1)-encoding genes. Only 45% of the isolates harbored the EAST1-encoding genes as detected by polymerase chain reaction. None of them hybridized with an AAF/II-encoding gene specific DNA probe and 35% (14/40) were positive in a PCR assay using primers specific for aggC, an accessory gene of the AAF/I-encoding operon. Cloning and sequence analysis of the aggA variant from one isolate, EAggEC 457, revealed 68.9% identity between its deduced amino acid sequence and those of the aggA product from the AAF/I-producing reference strain, E. coli 17.2. No major protein subunit was detected at the surface of EAggEC 457 compared to the bacterial surface extract of E. coli 17.2.
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Laboratoire de Bactériologie, Université d'Auvergne, Faculté de Pharmacie, Clermont-Ferrand, France. christiane.forestier@u-clermont1.fr
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Joly
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Forestier
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D018830:Adhesins, Escherichia coli / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001422:Bacterial Adhesion / Q000235:genetics* / Q000502:physiology; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000235:genetics*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015342:DNA Probes; D003967:Diarrhea / Q000382:microbiology*; D004768:Enterotoxins / Q000096:biosynthesis / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods; D011446:Prospective Studies; D017422:Sequence Analysis, DNA; D014774:Virulence
D018830:Adhesins, Escherichia coli; D001427:Bacterial Toxins; D015342:DNA Probes; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C034151:heat stable toxin (E coli)