L3. review of innate immunity Flashcards
what are the harmful effects of normal flora?
- when normal flora go to a different location (usually blood)
- due to decreased populations of harmless competitor microbes (example C diff)
- when immune system is weakened
define colonization?
presence of organisms on a body surface or in a lumen but NOT producing disease
define virulence?
the ability of an organism to cause disease
define contagious?
the ability of an organism to be spread
does contagious imply virulence?
no, it doesn’t have to be
can aids be spread through air?
no, only through blood or sexual contact
define lactoferrin?
enzyme in breast milk, binds to iron and inhibits bacterial growth
define lactoperoxidase?
a leukocyte enzyme - produces superoxide radicals that are toxic to microorganisms
define pseudomembranous colitis
formation of small swellings in the intestine - c diff
define bacteriosins
antibiotics produced by BACTERIA to protect them and their site from colonization of other bacteria
name a naturally antibiotic resistant organism that can grow opportunistically in the gut?
candida albicans
true vs opportunistic pathogens?
true - can cause disease in healthy people
opportunistic - cause disease when immune system is weakened
what does a pathogen need to infect a host? (3)
- entry site
- attachment component
- ability to survive host defenses
what are the various virulence factors used by bacteria? (5)
- adhesins
- biofilms
- extracellular enzymes
- toxins
- antiphagocytic factors
toxoplasmosis
a disease caused by a protozoan called toxoplasma
define invasiveness
the ability of a pathogen to invade tissues
What is resistance to infection diminished by (5)?
- Malnutrition
- cancer
- weak immune system
- drug therapy (corticosteroids/ antibiotics)
- damaged/abnormal anatomical structure
what is an important “virulence determinant” factor produced/accomplished by bacteria?
an enzyme with the ability to dissolve the “glue” b/w tissues to allow rapid entry/spread of bacteria! (entry into blood!!)
what is a coagulase?
an enzyme used by bacteria to cause blood coagulation and promote virulence
endotoxin vs exotoxin?
endo - released when bacteria burst (lps, can be released into blood!)
exo - released by bacteria (usually gram positive)
define leukocidins?
defense chemicals produced by some microbes which cause death of white blood cells
name examples of antiphagocytic factors?
- capsules
- outermembrane of gram neg
- waxy cell wall
- intact LPS
what is unique about the capsule of bacillus anthracis?
made of polypeptide (rather than the common polysaccharide making!)
what is an important factor for virulence of mycobacterium?
waxy cell wall
define listeriolysin
produced by listeria, forms pores which allow bacteria to escape phagocytes
how does bordetella pertusis survive inside phagocytes?
neutralizes respiratory burst
what is TACO?
protein produced by MYCOBACTERIA TB to inhibit phagolysosome fusion
- produces NH4+ to reverse acidification of phagolysosome
- promotes fusion w/ endosomes
what type of bacteria produce bacteriocin?
usually good bacteria (non pathogenic)
what are HAIs?
healthcare associated infections; caused by treatment for a different condition
define nosocomial infections?
HAI’s acquired in hospitals - occur as a result of chain of transmission
gardenella?
bacteria when lactobacillus isnt working - bacterial infection (as lactobacillus increases pH)
