Which type of bacteria is responsible for causing illness?

Pathogenic bacteria are the type of bacteria specifically associated with causing illness in humans, animals, and plants. These microorganisms can invade the body, multiply, and produce toxins that disrupt normal bodily functions, leading to various infections and diseases. Common examples of pathogenic bacteria include Salmonella, E. coli, and Listeria, which are often linked to foodborne illnesses.

In contrast, helpful bacteria, such as those found in probiotics, play beneficial roles in processes like digestion and nutrient absorption. Fermentative bacteria are involved in the fermentation process, which can be beneficial in food production, such as yogurt and sauerkraut, but they do not typically cause illness. Non-pathogenic bacteria do not cause disease and often exist in environments where they contribute to ecological balance or food production.

Thus, the classification of bacteria is crucial in food safety, as understanding which types can cause illness helps in implementing necessary precautions to prevent foodborne diseases.