Abstract |
Sorbitol-fermenting (SF) Shiga toxin (Stx)-producing Escherichia coli (STEC) O157:H- strains are emerging as causes of hemorrhagic colitis and the hemolytic-uremic syndrome in Europe. Using subtractive hybridization between SF STEC O157:H- strain 493/89 and STEC O157:H7 strain EDL933, three different fragments, of approximately 700 bp in length, were identified. Each demonstrated > 99% homology to genes encoding the enterohemorrhagic E. coli factor for adherence (efa1) and lymphostatin (lifA). Therefore, a cosmid library was constructed from SF STEC O157:H- strain 493/89, and one clone containing these fragments was sequenced. This sequencing demonstrated a 9669-bp open reading frame (ORF) that had 99.9% sequence homology to efa1 of STEC O111:H- strain E45035 and to lifA of an enteropathogenic E. coli O127:H6 strain E2348/69. In STEC O157:H7 strain EDL933, only small (ca. 3 kb) initial and terminal fragments of this ORF are present. PCR analysis with primers complementary to the efa1/lifA sequence of strain 493/89 indicated that the complete sequence is present in each of 10 SF STEC O157:H- isolates but in none of 10 STEC O157:H7 strains investigated. The presence of the complete efa1/lifA also in both tested E. coli O55:H7 strains supports the hypothesis that SF STEC O157:H- are phylogenetically closer to the proposed E. coli O55:H7 ancestor than STEC O157:H7. Our data demonstrate the presence of a potential virulence gene in SF STEC O157:H- that is only rudimentarily present in STEC O157:H7.
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Authors | Andreas Janka, Martina Bielaszewska, Ulrich Dobrindt, Helge Karch |
Journal | International journal of medical microbiology : IJMM
(Int J Med Microbiol)
Vol. 292
Issue 3-4
Pg. 207-14
(Sep 2002)
ISSN: 1438-4221 [Print] Germany |
PMID | 12398211
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Bacterial Proteins
- Bacterial Toxins
- DNA, Bacterial
- Efa1 protein, E coli
- Escherichia coli Proteins
- Shiga Toxins
- lymphostatin protein, E coli
- Sorbitol
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Topics |
- Bacterial Proteins
(genetics, isolation & purification, metabolism)
- Bacterial Toxins
(genetics, isolation & purification, metabolism)
- Base Sequence
- DNA, Bacterial
(chemistry, genetics)
- Escherichia coli O157
(genetics, metabolism)
- Escherichia coli Proteins
- Fermentation
- Gene Library
- Humans
- Nucleic Acid Hybridization
- Open Reading Frames
(genetics)
- Polymerase Chain Reaction
- Sequence Analysis, DNA
- Sequence Homology, Nucleic Acid
- Shiga Toxins
(biosynthesis, metabolism)
- Sorbitol
(metabolism)
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