The large plasmids of Shiga-toxin-producing Escherichia coli (STEC) are highly variable genetic elements.

Shiga-toxin-producing Escherichia coli (STEC) of different serotypes are known to harbour large plasmids. The aim of this study was to investigate, using the example of the plasmid-encoded serine protease EspP, whether these plasmids are a uniform genetic element present in STEC. Examination of 201 diarrhoeagenic E. coli strains using a newly developed espP-specific PCR showed that espP is specific for STEC and present in 57% of STEC belonging to 16 different serotypes. The espP genes of the 16 STEC serotypes varied to a certain extent, as shown by nucleotide sequence and restriction enzyme analyses, but the DNA regions adjacent to the espP gene were completely different. When two further STEC-plasmid markers, the catalase-peroxidase gene katP and the enterohaemorrhagic E. coli-haemolysin gene EHEC-hlyA were included, many combinations of the three markers were found, depending in part on the serotype. In addition, strains possessing none of the three markers still harboured large plasmids. In the most prevalent STEC serogroup, O157, it was observed that the plasmid of sorbitol-fermenting STEC O157:H- lacks the espP and katP genes although both genes are present in the plasmid of the non-sorbitol-fermenting STEC O157:H7. The EHEC-hlyA gene, however, is present in both. In conclusion, this study shows that the large plasmids of STEC are not uniform genetic elements but heterogeneous in both their gene composition and arrangement.

[1]  H. Karch,et al.  Isolation and Characterization of Sorbitol-Fermenting Shiga Toxin (Verocytotoxin)-Producing Escherichia coli O157:Hßtrains in the Czech Republic , 1998, Journal of Clinical Microbiology.

[2]  J. Nataro,et al.  Pet, an Autotransporter Enterotoxin from Enteroaggregative Escherichia coli , 1998, Infection and Immunity.

[3]  J. Colbourne,et al.  Evolution of Enterohemorrhagic Escherichia coli Hemolysin Plasmids and the Locus for Enterocyte Effacement in Shiga Toxin-Producing E. coli , 1998, Infection and Immunity.

[4]  T. Whittam,et al.  Genotypic and phenotypic changes in the emergence of Escherichia coli O157:H7. , 1998, The Journal of infectious diseases.

[5]  James P. Nataro,et al.  Diarrheagenic Escherichia coli , 1998, Clinical Microbiology Reviews.

[6]  M. Hattori,et al.  Complete nucleotide sequences of 93-kb and 3.3-kb plasmids of an enterohemorrhagic Escherichia coli O157:H7 derived from Sakai outbreak. , 1998, DNA research : an international journal for rapid publication of reports on genes and genomes.

[7]  A. Caprioli,et al.  Non-O157 Shiga toxin-producing Escherichia coli infections in Europe. , 1997, Emerging infectious diseases.

[8]  T. Chakraborty,et al.  Characterization of an exported protease from Shiga toxin‐producing Escherichia coli , 1997, Molecular microbiology.

[9]  H. Karch,et al.  EspP, a novel extracellular serine protease of enterohaemorrhagic Escherichia coli O157:H7 cleaves human coagulation factor V , 1997, Molecular microbiology.

[10]  H. Karch,et al.  A gene cluster closely related to type II secretion pathway operons of gram-negative bacteria is located on the large plasmid of enterohemorrhagic Escherichia coli O157 strains. , 1997, FEMS microbiology letters.

[11]  B. Finlay,et al.  Characterization of EspC, a 110-kilodalton protein secreted by enteropathogenic Escherichia coli which is homologous to members of the immunoglobulin A protease-like family of secreted proteins , 1996, Journal of bacteriology.

[12]  H. Karch,et al.  KatP, a novel catalase-peroxidase encoded by the large plasmid of enterohaemorrhagic Escherichia coli O157:H7. , 1996, Microbiology.

[13]  H. Lior,et al.  Growing Concerns and Recent Outbreaks Involving Non-O157:H7 Serotypes of Verotoxigenic Escherichia coli. , 1996, Journal of food protection.

[14]  H. Karch,et al.  Analysis of the EHEC hly operon and its location in the physical map of the large plasmid of enterohaemorrhagic Escherichia coli O157:h7. , 1996, Microbiology.

[15]  P. Sansonetti,et al.  SepA, the major extracellular protein of Shigella flexneri: autonomous secretion and involvement in tissue invasion , 1995, Molecular microbiology.

[16]  L. Beutin,et al.  Molecular analysis of the plasmid-encoded hemolysin of Escherichia coli O157:H7 strain EDL 933 , 1995, Infection and immunity.

[17]  J. Heesemann,et al.  Development of PCR for screening of enteroaggregative Escherichia coli , 1995, Journal of clinical microbiology.

[18]  J. Paton,et al.  Characterization of IS1203, an insertion sequence in Escherichia coli O111:H-. , 1994, Gene.

[19]  R. Curtiss,et al.  Isolation and characterization of a gene involved in hemagglutination by an avian pathogenic Escherichia coli strain , 1994, Infection and immunity.

[20]  P. Fratamico,et al.  Studies on Escherichia coli serotype O157:H7 strains containing a 60-MDa plasmid and on 60-MDa plasmid-cured derivatives. , 1993, Journal of medical microbiology.

[21]  T. Besser,et al.  A comparison of human and bovine Escherichia coli O157:H7 isolates by toxin genotype, plasmid profile, and bacteriophage lambda-restriction fragment length polymorphism profile. , 1993, The Journal of infectious diseases.

[22]  K. Jarvis,et al.  Distribution of the bundle-forming pilus structural gene (bfpA) among enteropathogenic Escherichia coli. , 1993, The Journal of infectious diseases.

[23]  J. Saunders,et al.  The large plasmids found in enterohemorrhagic and enteropathogenic Escherichia coli constitute a related series of transfer-defective Inc F-IIA replicons. , 1992, Plasmid.

[24]  F. Gunzer,et al.  Molecular detection of sorbitol-fermenting Escherichia coli O157 in patients with hemolytic-uremic syndrome , 1992, Journal of clinical microbiology.

[25]  H. Karch,et al.  Serological and biochemical properties of Shiga-like toxin (verocytotoxin)-producing strains of Escherichia coli, other than O-group 157, from patients in Germany. , 1992, Zentralblatt fur Bakteriologie : international journal of medical microbiology.

[26]  J. H. Carr,et al.  Influence of the 60-megadalton plasmid on adherence of Escherichia coli O157:H7 and genetic derivatives , 1990, Infection and immunity.

[27]  S. Ostroff,et al.  Toxin genotypes and plasmid profiles as determinants of systemic sequelae in Escherichia coli O157:H7 infections. , 1989, The Journal of infectious diseases.

[28]  S. Tzipori,et al.  Role of a 60-megadalton plasmid and Shiga-like toxins in the pathogenesis of infection caused by enterohemorrhagic Escherichia coli O157:H7 in gnotobiotic piglets , 1987, Infection and immunity.

[29]  J. Wells,et al.  Unusual verotoxin-producing Escherichia coli associated with hemorrhagic colitis , 1987, Journal of clinical microbiology.

[30]  M. Levine,et al.  A DNA probe to identify enterohemorrhagic Escherichia coli of O157:H7 and other serotypes that cause hemorrhagic colitis and hemolytic uremic syndrome. , 1987, The Journal of infectious diseases.

[31]  M. Levine,et al.  A plasmid of enterohemorrhagic Escherichia coli O157:H7 is required for expression of a new fimbrial antigen and for adhesion to epithelial cells , 1987, Infection and immunity.

[32]  R. Pridmore.  New and versatile cloning vectors with kanamycin-resistance marker. , 1987, Gene.

[33]  M. Levine,et al.  Detection of an adherence factor of enteropathogenic Escherichia coli with a DNA probe. , 1985, The Journal of infectious diseases.

[34]  J. Sambrook,et al.  Molecular Cloning: A Laboratory Manual , 2001 .

[35]  S. Formal,et al.  ESCHERICHIA COLI 0157:H7 STRAINS ASSOCIATED WITH HAEMORRHAGIC COLITIS IN THE UNITED STATES PRODUCE A SHIGELLA DYSENTERIAE 1 (SHIGA) LIKE CYTOTOXIN , 1983, The Lancet.

[36]  Harry B. McGee,et al.  Hemorrhagic colitis associated with a rare Escherichia coli serotype , 1983 .

[37]  H. Shay.  Transposition , 1999 .