Summary Theme 6 MBY251 study note

THEME 6- H U M A N & P L A N T - B A C T E R I A L
INTERACTIONS


Terminology
Pathogen: organism that grows/on a host and causes disease
Pathogenicity: the ability of a pathogen to cause disease
Virulence: measure of pathogenicity
Virulence factors: factors/strategies used by bacteria to cause disease
Compromised host: a host w/ low resistance (HIV/Cancer patient)
Opportunistic pathogen: causes disease only in the absence of normal host resistance
Attenuation: the decrease/ loss of virulence
Toxicity: organism causes disease by means of a toxin that inhibits host cell function/ kills cell (toxins travel to sites,
pathogen not inside host)
Effector: secretion & translocated virulence factors that interfere w/ host defenses
Compatible: pathogen can cause disease




Entry of pathogen
Entry points:
Human: nose, urogenital, mouth, wounds, mucous membranes, bites.
Plants: stomata, hydrathodes, lenticels, wounds, bites
Bacterial adherence facilitated by:
- Extracellular macromolecules (not covalently attached to bacterial cell surface, eg. Slime layer)
- Adhesins
- Fimbriae and pili
- Flagella


Transportation of bacteria in host