Which of the following is an example of infectious bacteria?

The selection of Salmonella, Campylobacter, and E. coli as examples of infectious bacteria is accurate because these microorganisms are all known to cause foodborne illnesses. Infectious bacteria can invade and multiply within the host, often leading to gastroenteritis or other symptoms related to food poisoning.

Salmonella is commonly found in raw poultry, unpasteurized eggs, and dairy products, and it can lead to severe gastrointestinal infection. Campylobacter is frequently associated with undercooked meats, particularly poultry, and it is one of the leading causes of bacterial foodborne illness worldwide. E. coli, particularly certain strains like E. coli O157:H7, is well-known for its presence in undercooked ground beef and contaminated produce, leading to serious health issues.

Other options provided contain different types of pathogens. For example, Listeria and C. botulinum are also infectious bacteria, but Hepatitis A is a virus, not a bacterium. Similarly, while Norovirus is a significant cause of foodborne illness, it is a virus, and parasites are not classified as bacteria either. Thus, the combination listed in option B comprises solely infectious bacteria, making it the correct choice.