Which three genera are most frequently documented as causative agents of human bacterial origin foodborne illness in the US?

• A. Streptococcus, Campylobacter and Salmonella
• B. Staphylococcus, Campylobacter and Salmonella
• C. Shigella, Campylobacter and Salmonella
• D. Staphylococcus, Shigella and Salmonella

Answer: (B)

The question tests which bacteria are most commonly responsible for human bacterial-origin foodborne illness in the United States. The trio that shows up most often across a wide range of foods and outbreaks includes Staphylococcus aureus, Campylobacter, and Salmonella.

Staphylococcus aureus causes illness primarily through enterotoxins produced in foods that are mishandled or left at room temperature. These toxins are heat-stable, so even proper cooking may not eliminate the illness once the toxin has formed. Foods frequently linked to this include dairy products, pastries, and deli salads where time-temperature control is poor.

Campylobacter is commonly associated with raw or undercooked poultry and, to a lesser extent, unpasteurized milk. It often leads to inflammatory diarrhea and is a leading cause of bacterial gastroenteritis in the US due to the abundance of poultry consumption and potential cross-contamination.

Salmonella is widespread in many foods, notably poultry, eggs, beef, dairy, and produce. It produces gastroenteritis that can be quite common and, in some cases, more severe, contributing to its high frequency in foodborne illness reports.

Other organisms like Shigella or Streptococcus can cause foodborne illness, but their overall frequency is lower when looking at the broad range of foods and outbreaks, so they don’t appear as frequently as the three listed above.

In short, these three genera consistently account for a large share of domestically acquired bacterial foodborne illnesses, reflecting their prevalence in common foods and their transmission pathways.