Shigella - Aeromonas Laboratory

Research Scientist

César Bin Kingombe, D.V.M., M.Sc., Ph.D.
Bureau of Microbial Hazards, Health Canada

Research Technical Support: Mary Rao

Research Activity

The genus Shigella consists of four serogroups:

  • Shigella dysenteriae (serogroup A) containing 15 serotypes,
  • Shigella flexneri (serogroup B) containing 8 serotypes,
  • Shigella boydii (serogroup C) containing 19 serotypes and
  • Shigella sonnei (serogroup D) with 1 serotype.

Humans and large primates are the only known natural reservoirs of Shigella spp. The four serogroups of Shigella differ in epidemiology. S. dysenteriae is associated with epidemics of serogroup 1 and is associated with the highest fatality rate. S. flexneri is the most frequently isolates species in developing countries. S. sonnei is the most implicated in developed countries and S. boydii is associated with outbreaks in Central and South America and rarely isolate in North America. Shigella spp. are major food and waterborne pathogens. The transmission of Shigellae to food is mainly due to poor hygiene and handling practices of sick people and healthy carriers. Person-to-person transmission is also common due to the low infective dose. Typical symptoms of infection include bloody diarrhoea, abdominal pain, fever, and malaise.

The isolation of viable Shigella spp. from food samples remains difficult using conventional methods. The lack of appropriate, selective culture media that will adequately suppress the growth of background microflora and specific concentration method which will discard background flora most of time overgrow and inhibit Shigella spp. Our research activities are focussed on setting up method for isolation of Shigella spp. from foods.

Current Research Activities

  1. Development of agar and broth media for the specific isolation of Shigella spp. from foods.
  2. Development of devices for the concentration of microorganisms and allergens from high volume food sample homogenates (iCropTheBug system) 250-500 mL.
  3. Development of filters for the removal of food debris from high volume food homogenates (250-500 mL).

Recent Publications

  1. César I. Bin Kingombe., Jean-Yves D'Aoust, Geert Huys, Lisa Hofmann, Mary Rao, and Judy Kwan. 2010. Multiplex PCR Method for the Detection of Three Enterotoxin Genes in Aeromonas spp. Journal of Applied and Environmental Microbiology. 76. 425-433.
  2. Tatjana Coklin, Jeffrey M. Farber, Lorna J. Parrigton, César I. Bin Kingombe, William H. Ross, and Brent R. Dixon. 2010. Immunomagnetic separation significantly improves the sensitivity of polymerase chain reaction in detection of Giardia duodenalis and Cryptosporidium spp. in dairy cattle. In press. Journal of Veterinary Diagnostic Investigation.
  3. César Bin Kingombe, Maria-Lucia Cerqueira-Campos, Yvon-Louis Trottier, and Josée Houle 2005. MFLP-25
  4. César Bin Kingombe, Maria-Lucia Cerqueira-Campos, Yvon-Louis Trottier, and Josée Houle 2005. MFLP-26
  5. César Bin Kingombe, Maria-Lucia Cerqueira-Campos, and Jeffrey M. Farber 2005. Molecular Strategies for the Detection, Identification, and Differentiation between Enteroinvasive Escherichia coli and Shigella spp. Journal of Food Protection. 68:239-245.
  6. César I. Bin Kingombe, Geert Huys, Denise Howald, Elizabeth Luthi, Jean Swings, and Thomas Jemmi. 2004. The Usefulness of Molecular Techniques to Assess the Presence of Aeromonas spp. Harboring Virulence Markers in Foods. International Journal of Food Microbiology. 94: 113-121.
  7. Patricia Thoerner, C. I. Bin Kingombe, K. Bogli-Stuber, B. Bissig-Choissat, T. M. Wassenaar, J. Frey, and T. Jemmi. 2003. PCR Detection of Virulence Genes in Yersinia enterocolitica and Yersinia pseudotuberculosis and Investigation of Virulence Gene Distribution. Applied and Environmental Microbiology, 69: 1810-1816.
  8. César I. Bin Kingombe, Elizabeth Luthi, Heidi Schlosser, Denise Howald, Monika Kuhn, and Thomas Jemmi. 2001. A PCR-based Test for Species-Specific Determination of Heat Treatment Conditions of Animal Meals as an Effective Prophylactic Method for Bovine Spongiform Encephalopathy. Meat Science. 57: 35-41.
  9. César I. Bin Kingombe, Geert Huys, Mauro Tonolla, M. John Albert, Jean Swings, Raffaele Peduzzi, and Thomas Jemmi. 1999. PCR Detection, Characterization, and Distribution of Virulence Genes in Aeromonas spp. Applied and Environmental Microbiology. 65: 5293-5302.

Related Links:

  1. Consumer information on Shigella

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