Virulence factors include which of the following answers?

• A. Toxins found in the outer-membrane of certain species of bacteria.
• B. Bacterial capsules that allow the bacterium to evade phagocytosis by immune cells.
• C. Proteins on the surface of a virus that allows the virus to bind to the host cell's surface.
• D. A and B only.
• E. All of the above.

Answer: (E)

Verified step by step guidance

1. Understand the definition of virulence factors: Virulence factors are molecules produced by pathogens (bacteria, viruses, fungi, and protozoa) that contribute to the pathogenicity of the organism and enable them to achieve colonization, immunoevasion, and immunosuppression.
2. Analyze option A: Toxins found in the outer-membrane of certain species of bacteria are known as endotoxins, which are a type of virulence factor that can trigger strong immune responses.
3. Analyze option B: Bacterial capsules are polysaccharide layers that surround some bacteria, helping them evade phagocytosis by immune cells, thus acting as a virulence factor.
4. Analyze option C: Proteins on the surface of a virus that allow the virus to bind to the host cell's surface are known as viral attachment proteins, which are crucial for the virus to infect host cells and are considered virulence factors.
5. Conclude that all options (A, B, and C) describe mechanisms that enhance the ability of pathogens to cause disease, thus all are considered virulence factors.