Bacteriology 1.3 Flashcards
plasmids types
F-plasmids- contain tra genes.
col plasmids- code for bacteriotoxins to kill other bacteria.
virulence plasmids- encode virulence factors, can convert normal bac to pathogen
R plasmids- contain genes that provide resistance to antibiotics
Transposons
DNA elements that move from one place in same bac DNA to another.
can carry virulence and antibiotic resistant genes.
e coli
really good at horizontal gene transfer
HGT
Facilitators of bacterial infection and survival within host
attachment
evasion of innate and adaptive responses
acquisition of limited nutrients
dissemination within a host and transmission to new hosts
ability to outcompete commensals at many stages
Bacterial adhesion systems
Pili-dependent- rod like projection with adhesion
Pili-independent- bac surface structure that interacts with host receptors
pedestals
EPEC and EHEC
LEE islands
secretion machinery..? codes for TYPE III secretion systems
T3SS
Type III secretion system
Molecular syringes, look like flagella. can secrete effectors.
really sophisticated.
how do bacteria deal with host defense?
primarily reside in extracellular milieu pocess virulence factors that prevent uptake by phags, or destroy them
possess factors to promote survival intracellular
some are in between, not in not out. NOT black/white
phagocytocys
phagosome> lysosome> ROS and NO kill the bug
CGD
NADPH oxidase genetic defect
chronic granulomatous diseases
survival of Extracellular pathogens
- capsules that prevent phagocytosis, and complement deposition
- can vary antigenic surface
*can secrete molecules that interfere with host defense
Toxins and enzymes that destroys chemokines, sIgA
intracellular pathogen survival
- resistant to ROOs and NO
- neutralize phagosome contents- secretion system
- escape from phagosome
- prevent phagolysosome fusion
Nutritional immunity
restricting access to nutrients so that bugs don’t grow.
constant battle for resources.
***fight over Fe, Mn, Zn, Cu, Mo, AAs, Carbs, O2.
three bacterial stages of invasion
dormant,
look up
Iron
under high demand by host and bug