E. coli/Shigella Molecular Serotyping Working Group

Defining Escherichia coli O antigens in the genomics era: a call for cooperation

For over 60 years, serology has been the standard method for classifying E. coli isolates, with several serotypes, including O157:H7, defining important global pathogens. The traditional method is based on antibody agglutination; however, only few laboratories can perform full serotyping due to the cost of maintaining antibodies for >180 known O groups. Additionally, the method is tedious and sometimes inconclusive, as significant numbers of isolates exhibit cross-reactivity or fail to agglutinate, defined as untypeable and non-typeable strains. Serology also cannot keep pace with potentially new antigens identified through genetic sequence-based methods. A robust, reproducible, adaptable, and transportable serotyping scheme is important and is especially critical for classifying Shiga toxin-producing E. coli (STEC), a pathotype that includes hundreds of serotypes.

From November 6-8, 2017, a workshop was held at the Pennsylvania State University in the United States, bringing together experts in E. coli serotyping, phylogenetics, and diagnostics to seed interest in defining E. coli O types in the genomics era.

PCR and sequence-based methods have been developed that can be used as an alternative to seroagglutination assays. However, the potential of these methods to supersede traditional phenotyping is dampened by several issues, including discrepancies between bioinformatic and traditional typing methods and the lack of molecular definitions for all known serogroups. Additionally, genomics has uncovered dozens of potentially new serogroups or mixed O type genes and a framework for naming and gaining acceptance of each is currently lacking.

Decisions were made to: 1) Create a website and NCBI BioProject for facilitating information sharing within the scientific community regarding the current state of molecular-based serotyping and knowledge gaps; 2) Create a unified serotyping scheme for E. coli and Shigella; 3) Propose merging the genus Shigella with E. coli and engaging stakeholders impacted by this taxonomical reclassification; 4) Continue to reach out to those members of the scientific community interested in participating, with the long-term goal of building a global working group on E. coli/Shigella nomenclature.

This website contains information from this meeting, and will be updated as new information emerges.  We thank Janssen Vaccines and Penn State’s College of Agricultural Sciences for funding supporting this workshop.

The workshop was organized by Edward Dudley, Associate Professor and Director of the E. coli Reference Center, and also included:

  1. Sara Christianson, Head of Reference Services Lab, Public Health Agency of Canada
  2. Linda Chui, Professor, University of Alberta Canada. Molecular Program Leader, Provincial Laboratory for Public Health in Alberta, Canada
  3. Adrian Cookson, Senior Scientist, AgResearch, Palmerston North, New Zealand
  4. Chobi DebRoy, Retired Director of the E. coli Reference Center, Penn State
  5. Sabine Delannoy, Research Scientist, Laboratory for Food Safety, French Agency for Food, Environment, and Occupational Health and Safety, France.
  6. Mark Eppinger, Associate Professor, University of Texas-San Antonio
  7. Patrick Fach, Senior Research Scientist, Laboratory for Food Safety, French Agency for Food, Environment, and Occupational Health and Safety, France
  8. Peter Feng, Research Microbiologist, US Food and Drug Administration (FDA)
  9. Eelco Franz, Department Head, Epidemiology of Gastroenteritis and Zoonoses, RIVM, Centre for Infectious Disease Control (The Netherlands)
  10. Pina Fratamico, Research Microbiologist, Molecular Characterization of Foodborne Pathogens Lab, United States Department of Agriculture (USDA)
  11. Angelika Fruth, National Reference Center for Salmonella and Other Enteric Pathogens, Robert Koch Institute, Germany
  12. Jayanthi Gangiredla, Staff Fellow, FDA
  13. Jeroen Geurtsen, Head Molecular Bacteriology, Janssen (Netherlands)
  14. Peter Hermans, Head Bacteriology Epidemiology, Janssen (Netherlands)
  15. Atsushi Iguchi, Associate Professor, Faculty of Agriculture, University of Miyazaki
  16. Claire Jenkins, Head of E. coli Reference Services, Public Health England
  17. James Johnson, Minneapolis VA Medical Center and University of Minnesota Department of Medicine, USA
  18. David Lacher, Research Microbiologist, FDA
  19. Chad Laing, National Microbiology Laboratory at Lethbridge, Public Health Agency of Canada
  20. Susan Leonard, Research Biologist, FDA
  21. Mark Mammel, Research Microbiologist, FDA
  22. Stefano Morabito, Senior Scientist and Deputy Director, European Union Reference Laboratory for coli Veterinary Public Health and Food Safety Departments, Istituto Superiore di Sanitá, Italy
  23. Brian Morrow, Head Molecular Biomarkers, Janssen (USA)
  24. David Needleman, Molecular Biologist, USDA
  25. Isha Patel, Staff Fellow, FDA
  26. Jan Poolman, Vice President Bacterial Vaccines Research & Early Development, Janssen (Netherlands)
  27. Peter Reeves, Professor of Microbiology, The University of Sydney
  28. Beth Roberts, Technician, Penn State E. coli Reference Center
  29. Flemming Scheutz, The International Escherichia coli and Klebsiella Centre, Denmark
  30. Nancy Strockbine, Chief of the Escherichia and Shigella Reference Unit, Division of Foodborne, Waterborne, and Environmental Diseases, US Centers for Disease Control
  31. Chris Whitehouse, Acting Director, Division of Molecular Biology, FDA
  32. Göran Widmalm, Professor of Bioorganic Chemistry, Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University