Lesson 3: Controlling and Testing for Microbial Hazards
Controlling Microbial Hazards
Know the microbial hazards to prevent them.
“……understanding the hazards, then preventing entry points into the facility and the establishment of niches and harborages” is key to food safety.
Examples of microbial hazards:
- L. monocytogenes (aka Listeria)
- E. coli O157:H7
- Salmonella spp.
- Campylobacter
Understanding and know the microbial load determination.
How can you tell if something is contaminated? It’s not always easy. There are several ways to verify cleanliness and to make sure that there are no microorganisms that might be contaminating food or equipment.
- Physical verification:
- Organoleptic (sight, smell, taste)
- Pre-operation inspections
- Microbiological verification:
- Bioluminescence/ATP – “Is it clean or is it dirty?” (immediate results and will tell you something is there, but will not tell you WHAT it is).
- Aerobic plate count (results in 2-3 days)
- Environmental monitoring (results in 3-5 days)
ATP (Adenosine Triphosphate) Bioluminescence Testing
- Advantages:
- Quick and immediate results.
- Measures level of sanitation by looking for levels of ATP common in food (and bacteria).
- Can track and trend results.
- Inexpensive.
- Disadvantages:
- Does not provide a count on the levels of bacteria on surfaces, only food residues.
ATP Swabs Testing
Click each question to learn more about ATP testing.
Answer the True/False Question
Microbiological Testing
Microbial testing is the first line of defense against disease-causing bacteria and toxins and supporting public health.
- Results can be had in 24-48 hours.
- Inexpensive.
- Various methods are used.
- Contact plates
- Dipsticks
- Petrifilm or pour plates
- Air testing
- Testing establishes internal microbiological standards.
- 10, 50, 100 colony forming units (CFU)/square centimeter
- Helps develop a testing program and establish a frequency of testing.
- Helps track and trend data.
- Critical for ready-to-eat (RTE) processes.
- e.g. Listeria monocytegenes
Sanitation Records and Training
- Use all sanitation records to evaluate the effectiveness of your sanitation program.
- Sanitation SOP records (pre-operation, operational, and corrective action)
- ATP/microbiological test results.
- Track and trend results.
- Learn from FSIS.
- Involve everyone in the facility. Training is critically important.
- Develop specific SOP’s for cleaning and sanitizing equipment.
Means any biological, chemical (including radiological), or physical agent that has the potential to cause illness or injury.
Food Safety and Inspection Service is a division of USDA to inspect and authorize food recalls.