CPFS Foodborne Illness & Pathogens 3

Question 1

Which of the following is a spore-forming anaerobic bacterium responsible for foodborne botulism and grows in improperly home-canned low-acid foods?

Accepted Answer

Clostridium botulinum

Answer

Clostridium botulinum produces heat-resistant spores and a potent neurotoxin in anaerobic, low-acid environments, which is why home-canned low-acid vegetables are a classic vehicle for botulism.

Question 2

What water activity (aw) level is generally considered the minimum below which most bacterial pathogens cannot grow?

Accepted Answer

0.85

Answer

Most bacterial pathogens require a water activity of at least 0.85 to grow; reducing aw below this level through drying, salting, or adding sugar inhibits bacterial proliferation.

Question 3

Which pH range is most inhibitory to the growth of the majority of bacterial foodborne pathogens?

Accepted Answer

Below 4.6 or above 9.0

Answer

Most bacterial pathogens grow best in the pH range of 4.6 to 9.0; a pH below 4.6 (high acid) or above 9.0 (high alkalinity) inhibits the growth of most foodborne pathogens.

Question 4

A food worker develops jaundice and fatigue one week before their symptoms appear. They have been handling ready-to-eat foods without gloves. Which pathogen is the greatest concern?

Accepted Answer

Hepatitis A virus

Answer

Hepatitis A virus is shed in stool during the incubation period (before symptoms appear), making infected handlers a high risk for contaminating ready-to-eat foods; jaundice is a classic symptom.

Question 5

Which population is at the GREATEST risk of developing hemolytic uremic syndrome (HUS) following infection with Shiga toxin-producing E. coli (STEC)?

Accepted Answer

Children under 5 years of age and the elderly

Answer

Children under 5 and elderly individuals are most vulnerable to HUS from STEC infections because their immune and renal systems are less able to withstand the damage caused by Shiga toxin.

(CPFS) Certified Professional in Foodservice Sanitation Practice Test

(CPFS) Certified Professional in Foodservice Sanitation Practice Test

CPFS Foodborne Illness & Pathogens 3