Background: The Aerobic Plate Count (APC) or Aerobic Colony Count (ACC) is used to determine the total number of viable aerobic bacteria of many species present in a food sample or on environmental surfaces. It can be estimated separately for three temperature ranges (psychrophilic 0-20°C, mesophilic 20-45°C and thermophilic >45°C) for all bacteria capable of growing in an aerobic environment (ambient air).
The method is often called the Aerobic colony count, Standard plate count, Mesophilic count or Total Plate Count. It is a purely a quantitative method and is not designed to identify specific pathogens but rather to give an overall bacterial count for food and surfaces. This method is often used to assess overall sanitation conditions within a food-processing plant.
Method: Health Canada (MFHPB-18)
Turn Around time: 5 days
Reported results: number of colonies per g (ml) of food sample or swab.
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 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
Aerobic colony count (ACC) is determined by pour plate culture technique.
It is reasonable to expect properly prepared and handled ready-to-eat processed or cooked foods, where no additional food handling was required after food preparation, to have an ACC of < 104 CFU per gram. An ACC of > 105 CFU per gram is usually evidence of post processing temperature abuse, inadequate cooking or improper storage conditions. ACC cannot be applied to raw, uncooked, unprocessed foods (e.g., fruits or vegetables), cultured or fermented products (e.g., cheese, yogurt or salami, etc.) since these foods are known and expected to have naturally occurring microbial flora. There are three categories of ACC listed in the table above, which are based on food type and the processing/handling the food has undergone.
Unsatisfactory levels for ACC is dependent on food category: Category 1: ≥ 105, Category 2: ≥ 107, Category 3: N/A
Category 1 – Cooked foods that do not require handling or processing; i.e., soups, bread, quiche, cooked meat, fish & seafood, vegetables, etc.
Category 2 – Cooked foods that require further handling prior to or during the preparation of the final product; i.e., hot dogs, sandwiches, burgers, etc.
Category 3 – Foods that have a high ACC due to the normal microbial flora associated; i.e., pitas, potato or pasta salad, salad rolls, fresh fruits, raw vegetables, cheese, yogurt, deli meats, etc.