Foodborne Bacterial Infections ◾ 367
6. From the epidemiology of a recent foodborne salmonellosis outbreak (instructor may provide or obtain from the Internet), analyze the causes of the incidence and suggest methods
that could be implemented to prevent this.
7. How does foodborne listeriosis differ from foodborne salmonellosis?
8. How can a pasteurized ready-to-eat food be contaminated with Lis. monocytogenes? What are
the implications of this contamination in a refrigerated ready-to-eat food?
9. List the individuals most susceptible to foodborne listeriosis.
10. “Since 1991, foodborne listeriosis cases have declined.” What could have helped in this
reduction in the United States?
11. Define nonpathogenic and pathogenic Esc. coli. How are the pathogenic strains grouped?
What are the characteristics of their toxins?
12. Describe the pathogenicity of foodborne EHEC infection in humans.
13. In a 1993 multistate foodborne outbreak, EHEC was isolated from the victims, improperly
cooked hamburger patties, and raw hamburger. A large amount of ground beef (several
thousand pounds) was suspected of being contaminated with this pathogen. Some food
microbiologists believe that when a large volume of a product is contaminated with a pathogen, there is a greater likelihood that a step in the processing operation is directly contaminating the product (which, in turn, could have been previously contaminated from a small
amount of contaminated raw material or environment). With this idea in mind, develop a
scenario that might have been involved in the EHEC contamination in large amounts of
hamburger patties in the incidence.
14. List two similarities and two differences between foodborne salmonellosis and shigellosis.
Define Shiga toxin.
15. Describe food association for a shigellosis outbreak and preventative measures to control the
disease. Why can food animals not be the source of Shigella?
16. “Campylobacteriosis is emerging as a major foodborne illness in many countries.” Justify
this statement.
17. Discuss the food association of and preventative measures against the causative pathogen
associated with campylobacteriosis.
18. What is the common sequele of campylobacteriosis?
19. Describe two important characteristics of the causative pathogen associated with foodborne
yersiniosis.
20. List the symptoms of yersiniosis and indicate how it is often misdiagnosed.
21. Discuss the control measures to reduce the incidence of foodborne yersiniosis.
22. List the Vibrio species considered to be human pathogens and what type of disease is associated with Vib. vulnificus?
23. Discuss how foods can be the vehicle of gastroenteritis caused by Vib. parahaemolyticus.
24. Describe the pathogenicity of Vib. vulnificus in humans.
25. Briefly describe foodborne infection caused by Bru. abortus, pathogenic Streptococcus, and
Cox. burnetii.
References
1. Tauxe, R.V., Salmonella: A postmodern pathogen, J. Food Prot., 54, 563–568, 1991.
2. CDC, National Salmonella Surveillance Overview, Atlanta, GA, US Department of Health and Human
Services, CDC, 2011.
6. From the epidemiology of a recent foodborne salmonellosis outbreak (instructor may provide or obtain from the Internet), analyze the causes of the incidence and suggest methods
that could be implemented to prevent this.
7. How does foodborne listeriosis differ from foodborne salmonellosis?
8. How can a pasteurized ready-to-eat food be contaminated with Lis. monocytogenes? What are
the implications of this contamination in a refrigerated ready-to-eat food?
9. List the individuals most susceptible to foodborne listeriosis.
10. “Since 1991, foodborne listeriosis cases have declined.” What could have helped in this
reduction in the United States?
11. Define nonpathogenic and pathogenic Esc. coli. How are the pathogenic strains grouped?
What are the characteristics of their toxins?
12. Describe the pathogenicity of foodborne EHEC infection in humans.
13. In a 1993 multistate foodborne outbreak, EHEC was isolated from the victims, improperly
cooked hamburger patties, and raw hamburger. A large amount of ground beef (several
thousand pounds) was suspected of being contaminated with this pathogen. Some food
microbiologists believe that when a large volume of a product is contaminated with a pathogen, there is a greater likelihood that a step in the processing operation is directly contaminating the product (which, in turn, could have been previously contaminated from a small
amount of contaminated raw material or environment). With this idea in mind, develop a
scenario that might have been involved in the EHEC contamination in large amounts of
hamburger patties in the incidence.
14. List two similarities and two differences between foodborne salmonellosis and shigellosis.
Define Shiga toxin.
15. Describe food association for a shigellosis outbreak and preventative measures to control the
disease. Why can food animals not be the source of Shigella?
16. “Campylobacteriosis is emerging as a major foodborne illness in many countries.” Justify
this statement.
17. Discuss the food association of and preventative measures against the causative pathogen
associated with campylobacteriosis.
18. What is the common sequele of campylobacteriosis?
19. Describe two important characteristics of the causative pathogen associated with foodborne
yersiniosis.
20. List the symptoms of yersiniosis and indicate how it is often misdiagnosed.
21. Discuss the control measures to reduce the incidence of foodborne yersiniosis.
22. List the Vibrio species considered to be human pathogens and what type of disease is associated with Vib. vulnificus?
23. Discuss how foods can be the vehicle of gastroenteritis caused by Vib. parahaemolyticus.
24. Describe the pathogenicity of Vib. vulnificus in humans.
25. Briefly describe foodborne infection caused by Bru. abortus, pathogenic Streptococcus, and
Cox. burnetii.
References
1. Tauxe, R.V., Salmonella: A postmodern pathogen, J. Food Prot., 54, 563–568, 1991.
2. CDC, National Salmonella Surveillance Overview, Atlanta, GA, US Department of Health and Human
Services, CDC, 2011.