Isolation and Identification of Salmonella from food and environmental samples.
Background: Salmonella spp. is one of the most common causes of food-borne illness, with about 1.4 million cases of Salmonellosis occurring annually in the United States and 900 cases in Canada.
Although Salmonella traditionally was thought of as being associated with animal products only, fresh produce like fruits and vegetables have been the source of major outbreaks, particularly recently. The organism also survives well on low-moisture foods, such as spices, which have been the vehicles for large outbreaks.
A few examples of foods that have been linked to Salmonella illness include meats, poultry, eggs, milk and dairy products, fish, shrimp, spices, yeast, coconut, sauces, freshly prepared salad dressings made with unpasteurized eggs, cake mixes, cream-filled desserts and toppings that contain raw egg, dried gelatin, peanut butter, cocoa, fresh produce (fruits and vegetables, such as tomatoes, peppers, and cantaloupes), and chocolate.
This method allows for the isolation and identification of different species and serotypes of Salmonella. It is also used as a confirmation test when positive results are obtained using more rapid qualitative PCR-methods.
Method: Health Canada (MFHPB-20)
Turn Around time: 5 Business Days
Reported Results: Negative or Positive food samples or 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 Instructions:
- 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 in a closed container at ambient temperature.
- 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
Salmonella spp. should be absent from ready-to-eat foods.