Listeria

Question 1

What temperatures can Listeria grow in?

Answer 1

See top slide on pg 4.

Question 2

What kinds of foods is Listeria monocytogenes associated with?

Answer 2

See top slide of pg 7.

Question 3

How does Listeria infect immunocompromised individuals? Why is this different from healthy adults?

Answer 3

See bottom slide on pg 5 and top slide on pg 6.

Question 4

What is meant by a “saprotroph”, and how does this relate to Listeria monocytogenes?

Answer 4

Saprotrophs are organisms found on dead and decaying material, and this is the natural reservoir for Listeria monocytogenes.

Question 5

What is especially noteworthy about the growth temperature and inhibitory salt concentrations for Listeria monocytogenes?

Answer 5

Grows at low temperatures, and at high salt concentrations; for specifics, see slide 7

Question 6

What is meant by “YOPI”?

Answer 6

Young, old, pregnant, immunocompromised. How does this relate to Listeria monocytogenes, and what other organisms discussed this semester also have this characteristic?

Question 7

How does Listeria monocytogenes infection differ between YOPIs and healthy adults?

Answer 7

See slide 10.

Question 8

How do US regulations differ from Europe in terms of Listeria monocytogenes presence in foods?

Answer 8

See top slide of page 8

Question 9

What are three common ways regulatory agencies would like industry to prevent Listeria monocytogenes in foods?

Answer 9

Use lethality step in process, add an antimicrobial, and/or have an excellent sanitation program in place.