Background: Escherichia coli (E. coli) bacteria are a group of bacteria which are commonly used as a marker or index of the potential presence of pathogens (i.e. food safety) and as indicators of overall food quality and the hygienic conditions present during food processing.
A gram negative rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded farm animals, E. coli is the only member of the coliform group that unquestionably is an inhabitant of the intestinal tract and it has become the definitive organism for the demonstration of fecal pollution of water and pre-processed food. E. coli may exist in the food processing plant environment where it can re-contaminate processed foods. Hence, the presence of E. coli in a heat-processed food indicates either process failure or, more commonly, post processing contamination from equipment or employees or from contact with contaminated raw foods or water.
While some strains of E. coli are pathogenic (causing disease) to humans, most strains of E. coli are not regarded as pathogens. This testing method is not specific to a single pathogen but is rather employed to confirm for the presence of E. coli, and to determine the total number of E. coli of all strains in a sample using the most probable number calculation.
Method: Health Canada (MFHPB-19)
Turn Around time: 4 Business Days
Reported Results: number of E. coli per gram of Food, per 100mL of water, or per swab
SPECIMEN REQUIREMENTS
Container/Kit: Submit 250 grams of food in a sterile plastic sample bag with round wire closure.
Collection information: See Section Sampling under Food Sampling
Requisition: Complete all fields of the form. See section Forms under Microbiology Sample Sheet.
Sterile bag: See section Form under Requisition for Containers and Supplies.
Preparation prior to transport: Keep refrigerated or frozen.
Shipping Information:
- Ship all foods in containers with hard walls and lids secured in the closed position.
- Shipping containers must be labelled with the submitting organization, unique identifier and contents e.g. FOOD SAMPLES on the outside of the container.
- Shipping containers used for food samples should be dedicated to food samples and not be used for other types of environmental samples.
- Ship dry foods and other shelf stable foods at ambient temperature in a closed container.
- Ship frozen foods in an insulated container with sufficient dry packs to maintain the frozen state.
- Ship perishable foods in an insulated container with sufficient cold packs to maintain a temperature as close to 4°C as possible. If ice is used, contain the ice in a manner that does not allow water contact with the samples.
- Submit all food samples to the laboratory as soon as possible.
TEST INFORMATION
Total coliform count is determined by the most-probable-number principle applied to a multiple tube fermentation test.
Presence of coliforms in a processed, cooked, ready-to-eat food is indicative of inadequate processing or post processing contamination resulting from poor handling of the product. A satisfactory limit cannot be applied to uncooked or raw foods such as salads and salad ingredients, raw fruits and vegetables, raw meats as well as some fermented foods, etc., since coliforms are regularly found in and/or on these foods.