Which of the following is NOT a microorganism that causes foodborne illness?

Lactobacillus acidophilus is the correct choice as it is not a microorganism that causes foodborne illness. Rather, it is a type of beneficial bacteria that is commonly found in yogurt and other fermented foods. Known for its probiotic properties, Lactobacillus acidophilus plays a positive role in gut health by aiding digestion and helping to balance the gut microbiota.

In contrast, Escherichia coli, Salmonella, and Norovirus are all known pathogens that can lead to foodborne illnesses. Escherichia coli, particularly certain virulent strains, can cause severe gastrointestinal infections. Salmonella is notorious for causing food poisoning often linked with raw or undercooked poultry and eggs. Norovirus is a highly contagious virus that can spread through contaminated food and surfaces, often leading to outbreaks in places like restaurants and cruise ships. Understanding the distinction between harmful microorganisms and beneficial ones is crucial in the study of food safety and sanitation.