21. Principles of Disease

Why do some pathogens destroy the host organism's C5a proteins?

What benefit do pathogenic bacteria obtain from secreting membrane-damaging toxins?

The C3b complement protein is incredibly important for opsonization of pathogenic material. How do some pathogens avoid opsonization by interfering with C3b?

Certain pathogens have Fc receptors on their surface to avoid which immune responses to infection?

Why would some pathogens inhibit the functions of C3 convertase as a defense mechanism against the host's immune cells?

Streptococcus pyogenes creates a C5a peptidase enzyme which breaks down the host's C5a proteins. Breaking down the C5a proteins has what result?

An encapsulated bacterium can be virulent because the capsule

a. resists phagocytosis.

b. is an endotoxin.

c. destroys host tissues.

d. kills host cells.

e. has no effect; because many pathogens do not have capsules, capsules do not contribute to virulence.

Match the following choices to the statements in questions 9 and 10:

a. Bordetella pertussis

b. Corynebacterium diphtheriae

c. Legionella pneumophila

d. Mycobacterium tuberculosis

e. none of the above

Resistant to destruction by phagocytes.

Name two ways Shigella can avoid host immune response.