Which type of organisms are considered pathogenic bacteria?

Pathogenic bacteria are specifically defined as those bacterial organisms that can cause disease or illness in humans or animals. These bacteria can lead to a range of health issues, from mild infections to severe diseases. Examples include Salmonella, E. coli, and Streptococcus. Understanding that pathogenic bacteria are harmful is critical in food safety and handling, as their presence can lead to foodborne illnesses.

In contrast, the other options involve organisms that do not fit the definition of pathogenic bacteria. Viruses and parasites are different types of pathogens but are not classified as bacteria. Cultured yogurt bacteria and bacteria that aid in digestion are beneficial microorganisms that promote health rather than cause disease. This distinction is essential for food handlers to ensure safety and prevent contamination in food.