Pathogenesis
from: Acanthamoeba: Biology and Pathogenesis (Author: Naveed Khan). Caister Academic Press, U.K. (2009)
Abstract
• Acanthamoeba keratitis
In vivo models
Ex vivo models
In vitro models
• Granulomatous amoebic encephalitis due to Acanthamoeba
In vivo models
Ex vivo models
In vitro models
• An opportunist with pathogenic potential
• Crossing the biological barriers
• Cornea
• Traversal of the blood-brain barrier
• Direct virulence factors
• Contact-dependent mechanisms
Acanthamoeba binds to extracellular matrix proteins
Adhesion to the host cells
Host intracellular signaling in response to Acanthamoeba
Phagocytosis
Phagosome formation and fusion with lysosomes
Lysosomal enzymes
Ecto-ATPases
Neuraminidase activity
Superoxide dismutases
Acanthamoeba activates plasminogen
• Contact-independent mechanisms
Hydrolytic enzymes
Elastase
Proteases
Phospholipases
Glycosidases (also called glycoside hydrolases)
• Indirect virulence factors
Morphology
Temperature tolerance, osmotolerance and growth at different pH
Phenotypic switching
Chemotaxis
Ubiquity
Biofilms
Effect of cholesterol (or sterol biosynthesis) on Acanthamoeba virulence
Host factors
