Microbial Contaminants: A Guide to Food Safety

1. The Microworld

2. Apply Your Knowledge: Test Your Food Safety Knowledge • True or False:Bacillus cereus is commonly associated with cereal crops, such as rice 2.True or False: A foodborne intoxication results when a person eats food containing pathogens, which then grow in the intestines and cause illness 3.True or False: Cooking food to the required minimum internal temperature can help avoid listeriosis 4.True or False: A person with shigellosis may experience bloody diarrhea 5.True or False:Highly acidic food typically does not support the growth of foodborne microorganisms 2-2

3. Microbial Contaminants • Microorganism • Small, living organism • Pathogen • Illness-causing microorganism • Toxin • Poison

4. Microbial Contaminants • Microorganisms That Can Contaminate Food and Cause Foodborne Illness Bacteria Viruses Parasites Fungi

5. What Microorganisms Need to Grow: FAT TOM A T F Temperature Food Acidity T M O Moisture Time Oxygen

6. What Microorganisms Need to Grow: FAT TOM • Food • Foodborne microorganisms require nutrients to grow. Specifically carbohydrates and proteins • These are found in potentially hazardous food including: • Meat • Poultry • Dairy products • Eggs F Food

7. What Microorganisms Need to Grow: FAT TOM • Acidity • Foodborne microorganisms grow best in food that has a neutral or slightly acidic pH (7.5 to 4.6) • Most food falls into this range A Acidity pH Scale Acidic 7.5–4.6 ideal for bacterial growth Neutral Alkaline

8. What Microorganisms Need to Grow: FAT TOM • Temperature • Foodborne microorganisms grow well at temperatures between 41˚F and 135˚F (5˚C and 57˚C) T Temperature 135°F (57°C) The Temperature Danger Zone 41°F (5°C)

9. What Microorganisms Need to Grow: FAT TOM Time • Foodborne microorganisms need sufficient time to grow • 4 hours or more in TDZ=growth high enough to cause illness T Time

10. What Microorganisms Need to Grow: FAT TOM • Oxygen • Some foodborne microorganisms require oxygen to grow, while others grow when oxygen is absent O Oxygen

11. What Microorganisms Need to Grow: FAT TOM • Moisture • Most foodborne microorganisms require moisture to grow • The amount of moisture available in food for this growth is called water activity (aw) • Potentially hazardous food typically has an aw of .85 or higher M Moisture

12. Controlling the Growth of Microorganisms • The two conditions you can control: • Temperature • Refrigerate or freeze food properly • Cook food properly • Time • Minimize time food spends in the temperature danger zone (TDZ)

13. Apply Your Knowledge: What I Need to Grow! • Which conditions typically support the growth of microorganisms? Food that is high in fat Food that contains protein pH of 9.0 Temperature of 155F (68C) or higher Dry environment 1 2 3 4 5 2-13

14. Classifying Foodborne Illness • Foodborne Infections • Result when a person eats food containing pathogens, which then grow in the intestines and cause illness • Foodborne Intoxications • Result when a person eats food containing toxins that cause illness • Foodborne Toxin-Mediated Infections • Result when a person eats food containing pathogens, which then produce illness-causing toxins in the intestines

15. Bacteria That Cause Foodborne Illness • Basic Characteristics • Living, single-celled organism • Can be carried by food, water, soil, animals, humans, or insects • Can reproduce very rapidly under favorable conditions

16. Bacteria That Cause Foodborne Illness • Basic Characteristics: continued • Some survive freezing • Some change into a different form called sporesto protect themselves • Some spoil food; others cause illness • Some produce toxins that cause illness

17. Spores • Certain bacteria can change into a different form, called spores, to protect themselves • Spores • Form when nutrients are not available • Are commonly found in soil and contaminate food grown there • Can contaminate meat, poultry, fish, and other food exposed to soil or dust

18. Spores • Spores • Can resist heat, allowing them to survive cooking temperatures • Can revert back to a form capable of growth when: • Food is not stored at the proper temperature • Food is not held or cooled properly

19. Major Foodborne Illnesses Caused by Bacteria • Infections • Campylobacteriosis • Salmonellosis • Shigellosis • Listeriosis • Vibrio parahaemolyticus Gastroenteritis • Vibrio vulnificus Primary Septicemia/Gastroenteritis

20. Infection: Campylobacteriosis Illness:CampylobacteriosisBacteria: Campylobacterjejuni Most Common Symptoms Commonly Associated Food Most Common Symptoms • Diarrhea (may be bloody) • Abdominal cramps • Fever • Headache • Poultry • Water contaminated with the bacteria Diarrhea Abdominal Cramps Fever Headache

21. Preventing Campylobacteriosis • To reduce the bacteria in food: • Cook food, particularly poultry, to required minimum internal temperatures • To prevent the transfer of the bacteria: • Prevent cross-contamination between raw poultry and ready-to-eat food.

22. Infection: Salmonellosis Illness:SalmonellosisBacteria: Salmonella spp. Commonly Associated Food Most Common Symptoms • Diarrhea • Abdominal cramps • Vomiting • Fever • Poultry and eggs • Dairy products • Beef

23. Preventing Salmonellosis • To reduce the bacteria in food: • Cook raw beef, poultry, and eggs to required minimum internal temperatures. • To prevent the transfer of the bacteria: • Minimize cross-contamination between raw meat and poultry and ready-to-eat food. • Exclude foodhandlers diagnosed with salmonellosis.

24. Infection: Shigellosis Illness:ShigellosisBacteria: Shigella spp. Most Common Symptoms Commonly Associated Food Most Common Symptoms • Food easily contaminated by hands • Food in contact with contaminated water (i.e., produce) • Bloody diarrhea • Abdominal pain and cramps • Fever (occasionally)

25. Preventing Shigellosis • To prevent the transfer of the bacteria: • Exclude foodhandlers if they: • Have diarrhea • Have been diagnosed with shigellosis • Wash hands when necessary • Control flies inside and outside the establishment

26. Infection: Listeriosis Illness:ListeriosisBacteria: Listeria monocytogenes Most Common Symptoms Commonly Associated Food Most Common Symptoms • Raw meat • Unpasteurized milk and milk products • Ready-to-eat food including: • Deli meats • Hot dogs • Soft cheese • Pregnant women • Spontaneous abortion of the fetus • Newborns • Sepsis • Pneumonia • Meningitis

27. Preventing Listeriosis • It is critical to: • Discard product that has passed its use-by or expiration date • Avoid using unpasteurized dairy products • To reduce the bacteria in food: • Cook raw meat to required minimum internal temperatures • To prevent the transfer of the bacteria: • Prevent cross-contamination between raw or undercooked and ready-to-eat food

28. Infection: Vibrio parahaemolyticus Gastroenteritis Illness:Vibrio parahaemolyticus GastroenteritisBacteria: Vibrio parahaemolyticus Commonly Associated Food Most Common Symptoms • Raw or partially cooked oysters • Diarrhea and abdominal cramps • Nausea and vomiting • Low grade fever and chills

29. Preventing Vibrio parahaemolyticus Gastroenteritis • Most Important Prevention Measures • Purchase oysters from approved, reputable suppliers • Cook oysters to the required minimum internal temperature

30. Infection: Vibrio vulnificus Primary Septicemia Illness:Vibrio vulnificus Primary SepticemiaBacteria: Vibro vulnificus Commonly Associated Food Most Common Symptoms • Raw or partially cooked oysters (People with liver disease and diabetes) • Fever and chills • Nausea • Skin lesions • Diarrhea and vomiting possible

31. Infection: Vibrio vulnificus Gastroenteritis Illness:Vibrio vulnificus GastroenteritisBacteria: Vibrio vulnificus Commonly Associated Food Most Common Symptoms • Raw or partially cooked oysters (Otherwise healthy people) • Diarrhea • Abdominal cramps

32. Preventing Vibrio vulnificus Septicemia/Gastroenteritis • Most Important Prevention Measures • Purchase oysters from approved, reputable suppliers. • Cook oysters to the required minimum internal temperature. • Inform people at risk to consult a physician before regularly consuming raw or partially cooked oysters

33. Major Foodborne Illnesses Caused by Bacteria • Intoxications • Bacillus cereus Gastroenteritis • Staphylococcal Gastroenteritis • Botulism

34. Intoxication: Bacillus cereus Gastroenteritis Illness:Bacillus cereus GastroenteritisBacteria: Bacillus cereus (Diarrheal Toxin) Most Common Symptoms Commonly Associated Food Most Common Symptoms • Watery diarrhea • Abdominal cramps and pain • Vomiting is absent • Cooked corn • Cooked potatoes • Cooked vegetables • Meat products

35. Intoxication: Bacillus cereus Gastroenteritis Illness:Bacillus cereus GastroenteritisBacteria: Bacillus cereus (Emetic Toxin) Commonly Associated Food Most Common Symptoms • Nausea • Vomiting • Cooked rice dishes including: • Fried rice • Rice pudding

36. Preventing Bacillus cereus Gastroenteritis • To reduce the bacteria in food: • Cook food to required minimum internal temperatures • To prevent the growth of the bacteria: • Hold food at the proper temperature • Cool food properly

37. Intoxication: StaphylococcalGastroenteritis Illness:Staphylococcal GastroenteritisBacteria: Staphylococcus aureus Most Common Symptoms Commonly Associated Food Most Common Symptoms Commonly Associated Food • Nausea • Vomiting and retching • Abdominal cramps • Salads containing potentially hazardous food: • Egg, tuna, chicken, macaroni • Deli meats

38. Preventing Staphylococcal Gastroenteritis • To prevent the transfer of the bacteria to food: • Wash hands after touching the body • Cover cuts on hands and arms • Restrict foodhandlers with infected cuts on hands and arms • To prevent the growth of the bacteria in food: • Minimize the time food spends in the TDZ • Cook, hold, and cool food properly

39. Intoxication: Botulism Illness:BotulismBacteria: Clostridium botulinum Commonly Associated Food Most Common Symptoms • Improperly canned food • ROP food • Temperature abused vegetables like: • Baked potatoes • Untreated garlic-and-oil mixtures Initially: • Nausea and Vomiting Later: • Weakness • Double vision • Difficulty speaking and swallowing

40. Preventing Botulism • Most Important Prevention Measures: • Hold, cool, and reheat food properly • Inspect canned food for damage

41. Major Foodborne Illnesses Caused by Bacteria • Toxin-Mediated Infections: • Clostridium perfringens Gastroenteritis • Hemorrhagic Colitis

42. Toxin-Mediated Infection: Clostridium perfringens Gastroenteritis Illness:Clostridium perfringens GastroenteritisBacteria: Clostridium perfringens Commonly Associated Food Most Common Symptoms • Meat • Poultry • Meat and poultry dishes: • Stews • Gravies • Diarrhea • Severe abdominal pain • Fever and vomiting are absent

43. Preventing Clostridium perfringens Gastroenteritis • To prevent growth of the bacteria (especially in meat dishes): • Cool and reheat food properly • Hold food at the proper temperature

44. Toxin-Mediated Infection:Hemorrhagic Colitis Illness:Hemorrhagic ColitisBacteria: Shiga toxin-producing Escherichia coli Most Common Symptoms Commonly Associated Food Most Common Symptoms • Ground beef (raw and undercooked) • Contaminated produce • Diarrhea (eventually becomes bloody) • Abdominal cramps • Severe cases can result in hemolytic uremic syndrome (HUS)

45. Preventing Hemorrhagic Colitis • To reduce the bacteria in food: • Cook food, particularly ground beef, to required minimum internal temperatures • To prevent the transfer of the bacteria to food: • Prevent cross-contamination between raw meat and ready-to-eat food • Exclude employees from the establishment if: • They have diarrhea • They have been diagnosed with hemorrhagic colitis

46. Apply Your Knowledge: Who Am I? • 1. Identify the bacteria: • Many farm animals naturally carry me • I have been found in produce that has come in contact with animal waste • I am often associated with poultry and eggs • I can produce diarrhea and vomiting in those who consume me • 2. Identify the bacteria: • I am found in the waters of the Gulf of Mexico • I have been associated with raw oysters • I can produce two different illnesses • Purchasing oysters from approved, reputable suppliers can prevent me 2-46

47. Apply Your Knowledge: Who Am I? • 3. Identify the bacteria: • I am found in the soil • I have been associated with rice • I can produce two different types of toxins that cause illness • Cooking food to required minimum internal temperatures can destroy me • 4. Identify the bacteria: • I form spores • The toxins I produce cause illness • I have been associated with meat stews • I can produce diarrhea and severe abdominal pain • I am carried in the intestines of animals and humans 2-47

48. Apply Your Knowledge: Who Am I? • 5. Identify the bacteria: • I do not need oxygen to grow • I can cause double vision and difficulty swallowing • I am commonly associated with produce from the soil • I produce a deadly toxin when food is temperature abused 2-48

49. Basic Characteristics of Viruses • Viruses • Some may survive freezing • Can be transmitted from: • Person to person • People to food • People to food-contact surfaces • Usually contaminate food through a foodhandler’s improper hygiene • Can contaminate both food and water supplies

50. Major Foodborne Illnesses Caused by Viruses • Viral Foodborne Illnesses • Hepatitis A • Norovirus Gastroenteritis