Enterohemorrhagic Escherichia coli(EHEC) Strains of Serogroup O118 Display Three Distinctive Clonal Groups of EHEC Pathogens

ABSTRACT A recent case report of a child infected with enterohemorrhagic Escherichia coli (EHEC) of serotype O118:H16 in Bavaria, in association with the isolation of a bovine O118 strain on the same farm (A. Weber, H. Klie, H. Richter, P. Gallien, M. Timm, and K. W. Perlberg, Berl. Muench. Tieraerztl. Wochenschr. 110:211–213, 1997), prompted us to investigate the relationship between bovine and human strains of serogroup O118. A total of 29 human O118 E. coli strains from Europe (21), Canada (4), and Peru (4) were compared by virulence typing and macrorestriction analysis with 7 bovine O118 EHEC strains isolated in Bavaria. Twenty-five of the human strains were characterized as EHEC. By serotyping and determination of the virulence-associated factors Shiga toxin (stx1 stx2 stx2 variants), intimin (eae), and EHEC hemolysin (HlyEHEC), three distinctive groups of O118 human pathogens were identified. Most of the strains belonged to serotype O118:H16, displaying the virulence traits Stx1, intimin, HlyEHEC, and EspP/PssA (group 1). In addition, we identified strains of serotype O118:H12 (Stx2d only; group 2) and of serotype O118:H30 (Stx2 and intimin; group 3). Macrorestriction analysis withBlnI and XbaI revealed that all strains with a single O118 serotype profile (O118:H12, O118:H16, and O118:H30) belonged to one clonal cluster, irrespective of their origin. Group 1 strains clustered in the same clonal group as the bovine O118:H16 strains. Moreover, four pairs of strains of different origins and indistinguishable by all other methods applied were identified as group 1 strains. Our data support the direct transmission of an EHEC O118:H16 strain from a calf to a 2-year-old boy in the above-mentioned case report. Since bovine and human O118:H16 strains represent the same clones, they must be considered zoonotic EHEC pathogens. In contrast, EHEC strains of serotypes O118:H12 and O118:H30 have been isolated only from humans, indicating a reservoir for certain human O118 EHEC strains other than bovines.

[1]  A. Caprioli,et al.  A New Shiga Toxin 2 Variant (Stx2f) fromEscherichia coli Isolated from Pigeons , 2000, Applied and Environmental Microbiology.

[2]  S. McEwen,et al.  Associations between Virulence Factors of Shiga Toxin-ProducingEscherichia coli and Disease in Humans , 1999, Journal of Clinical Microbiology.

[3]  T. Kawakita,et al.  Epidemic of Gastrointestinal Tract Infection Including Hemorrhagic Colitis Attributable to Shiga Toxin 1-producingEscherichia coli O118:H2 at a Junior High School in Japan , 1999, Pediatrics.

[4]  H. Karch,et al.  Clonal analysis of Shigatoxin-producing E. coli (STEC) of serogroup O118 reveals these strains to be zoonotic pathogens : Abstracts of the 2. international symposium of the European Study Group on Enterohemorrhagic Escherichia coli, Brussels/Belgium , 1999 .

[5]  P. Goldwater,et al.  New perspectives on the role of Escherichia coli O157:H7 and other enterohaemorrhagic E. coli serotypes in human disease. , 1998, Journal of medical microbiology.

[6]  S. Lauwers,et al.  Identification of New Verocytotoxin Type 2 Variant B-Subunit Genes in Human and Animal Escherichia coliIsolates , 1998, Journal of Clinical Microbiology.

[7]  Kim Ziebell,et al.  Association of Enterohemorrhagic Escherichia coliHemolysin with Serotypes of Shiga-Like-Toxin-ProducingEscherichia coli of Human and Bovine Origins , 1998, Applied and Environmental Microbiology.

[8]  L. Wieler,et al.  Virulence Properties of Shiga Toxin-Producing Escherichia coli (STEC) Strains of Serogroup O118, a Major Group of STEC Pathogens in Calves , 1998, Journal of Clinical Microbiology.

[9]  H. Lior,et al.  Isolation and virulence factors of verocytotoxin-producing Escherichia coli in human stool samples. , 1997, Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases.

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

[11]  B. Swaminathan,et al.  Molecular characterization of the gene encoding H antigen in Escherichia coli and development of a PCR-restriction fragment length polymorphism test for identification of E. coli O157:H7 and O157:NM , 1997, Journal of clinical microbiology.

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

[13]  L. Wieler,et al.  Shiga toxin-producing Escherichia coli strains from bovines: association of adhesion with carriage of eae and other genes , 1996, Journal of clinical microbiology.

[14]  L. Wieler,et al.  The enterohemolysin phenotype of bovine Shiga-like toxin-producing Escherichia coli (SLTEC) is encoded by the EHEC-hemolysin gene. , 1996, Veterinary microbiology.

[15]  S. Schwarz,et al.  Evaluation and comparison of molecular techniques for epidemiological typing of Salmonella enterica subsp. enterica serovar dublin , 1996, Journal of clinical microbiology.

[16]  H. Lior,et al.  Prevalence of the eaeA gene in verotoxigenic Escherichia coli strains from dairy cattle in Southwest Ontario , 1996, Epidemiology and Infection.

[17]  M. Blanco,et al.  Serogroups of Escherichia coli isolated from piglets in Spain. , 1996, Veterinary microbiology.

[18]  A. Caprioli,et al.  Genotyping of Shiga-like toxin genes in non-O157 Escherichia coli strains associated with haemolytic uraemic syndrome. , 1995, Journal of medical microbiology.

[19]  F. Gunzer,et al.  Construction of recombinant Shiga-like toxin-IIv (SLT-IIv) and its use in monitoring the SLT-IIv antibody status of pigs. , 1995, Veterinary microbiology.

[20]  A. Borczyk,et al.  Sequence heterogeneity of the eae gene and detection of verotoxin-producing Escherichia coli using serotype-specific primers , 1994, Epidemiology and Infection.

[21]  A. Edefonti,et al.  Communitywide Outbreak of Hemolytic-Uremic Syndrome Associated with Non-O157 Verocytotoxin-Producing Escherichia coli , 1994 .

[22]  J. Mainil,et al.  Association between the effacing (eae) gene and the Shiga-like toxin-encoding genes in Escherichia coli isolates from cattle. , 1993, American journal of veterinary research.

[23]  L. Wieler,et al.  Characterization of Shiga-like toxin producing Escherichia coli (SLTEC) isolated from calves with and without diarrhoea. , 1992, Zentralblatt fur Bakteriologie : international journal of medical microbiology.

[24]  M. McKee,et al.  Two copies of Shiga-like toxin II-related genes common in enterohemorrhagic Escherichia coli strains are responsible for the antigenic heterogeneity of the O157:H- strain E32511 , 1991, Infection and immunity.

[25]  J. Mainil,et al.  Description de 70 souches d'Escherichia coli d'origine bovine possédant les gènes des vérotoxines , 1991 .

[26]  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.

[27]  H. Karch,et al.  Single primer pair for amplifying segments of distinct Shiga-like-toxin genes by polymerase chain reaction , 1989, Journal of clinical microbiology.

[28]  M. Karmali,et al.  Infection by verocytotoxin-producing Escherichia coli , 1989, Clinical Microbiology Reviews.

[29]  J. Peiris,et al.  Serotypes of verocytotoxigenic Escherichia coli isolated from cattle and buffalo calf diarrhoea , 1986 .

[30]  I. Ørskov,et al.  2 Serotyping of Escherichia coli , 1984 .

[31]  F. Orskov.  Antigenic relationships between o groups 1-112 of E. coli and Wramby's o groups 26w-43w. 10 new o groups: 114-123. , 1952, Acta pathologica et microbiologica Scandinavica.