Listeria resists phagocytosis in phagosomes (phagolysosomes) due to

Listeria resists phagocytosis in
phagosomes (phagolysosomes) due to:
a) β-hemolysin
b) Caspases
c) Cell membrane adhesion molecules
d) Opacity associated protein (OAP)
Correct Answer - A
Ans. is. ‘a’ i. e., β-hemolysin
Most important step in pathogenesis of listeriosis is the survival and
multiplication of L monocytogenes in phagocytes (macrophages),
host epithelial cells and hepatocytes.

  • The most importaflt deterrminant of pathogenesis k
    listeriolysin O (LLO), A beta- hemolysin . LLO causes lysis of
    membrane of phagosomes within phagocytes and
    helps in intracellular survival of L monocytogenes.
  • Iron is an important virulence factor. Listeria produce siderophores
    and are able to obtain iron from transferrin. Immunity to
    listeria is primary cell mediated. Immunity can be transferred by
    sensitized lymphocytes but not by antibodies.