4 ways bacteria avoid host defences
resist complement, resist antibodies, resist phagocytosis, inhibit IC killing
how do bacteria resist complement
thick cell wall (M. tuberculosis); capsule (N, meningitidis)
how do bacteria resist antibodies
protease (S. pneumonia); antigenic variation (N. gonorrhoeae)
how do bacteria resist phagocytosis
polysaccharide capsule (N, meningitidis); debilitate phagocytes (Y. pestis); hide inside other cells (Chlamydia)
how do bacteria inhibit IC killing
escape from phagosome (L. monocytogenes); block phagosome maturation (M. tuberculosis)