Analysis of the enterohemorrhagic Escherichia coli O157 DNA region containing lambdoid phage gene p and Shiga-like toxin structural genes.
In this study, we determined the nucleotide sequence of the p gene contained within a 5-kb EcoRI restriction fragment cloned from Shiga-like toxin II (SLT-II)-converting phage 933W of Escherichia coli O157:H7 strain EDL933. The p gene was 702 bp long and had 95.3% sequence similarity to the p gene of phage lambda. Multiple hybridization patterns were obtained when genomic DNA fragments were hybridized with both p and slt-I, slt-II, or slt-IIc sequences. All O157 isolates also possessed an analog of lambda gene p which was not linked with either slt-I or slt-II. Restriction fragment length polymorphism comparisons of clinical O157 isolates and derivates undergoing genotype turnover during infection were made, and loss of large DNA fragments that hybridized with slt-II and p sequences was observed. To further analyze the DNA region containing the p and slt genes, we amplified fragments by using a PCR with one primer complementary to p and the other complementary to either the slt-I or the slt-II gene. PCR analysis with enterohemorrhagic E. coli O157 and non-O157 strains yielded PCR products that varied in size between 5.1 and 7.8 kb. These results suggest that even within O157 isolates, the genomes of SLT-converting phages differ. The methods described here may assist in further investigation of SLT-encoding phages and their role in the epidemiology of infection with enterohemorrhagic E. coli.
Datz
M
M
Institut fur Hygiene und Mikrobiologie der Universitat Wurzburg, Germany.
Janetzki-Mittmann
C
C
Franke
S
S
Gunzer
F
F
Schmidt
H
H
Karch
H
H
D001427:Bacterial Toxins / Q000235:genetics*; D010582:Bacteriophage lambda / Q000235:genetics*; D015139:Blotting, Southern; D015342:DNA Probes; D004269:DNA, Bacterial / Q000235:genetics; D004768:Enterotoxins / Q000235:genetics*; D004927:Escherichia coli Infections / Q000382:microbiology; D019453:Escherichia coli O157 / Q000235:genetics*; D005798:Genes, Bacterial; D005814:Genes, Viral; D006463:Hemolytic-Uremic Syndrome / Q000235:genetics / Q000382:microbiology; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D022641:Shiga Toxin 2
D001427:Bacterial Toxins; D015342:DNA Probes; D004269:DNA, Bacterial; D004768:Enterotoxins; D022641:Shiga Toxin 2