L2 - Challenge Of Microorganisms Flashcards
What are the 5 types of microorganisms (which are unicellular which are multicellular)
Uni - bacteria, virus, fungi/yeast, protozoa
Multi - helminths
What is a pathogen
Microorganism/infectious agent that cause disease
What are the 3 big killers?
Malaria, HIV/AIDS & tuberculosis
How do we acquire infections?
- physical contact
- ingestion
- inhalation
- vectors
- occurs via mucosal sites (exploits these sites for transmission
Is there more genes in human m,icrobiome of human genome (give rough ratio)
More in human Microbiome (40-100:1)
What makes microorganism harmful? Give microbe specific and host specific factors.
Virulence factors and inflammation
What is site specific/host specific (intrahost or interhost)
Intra host - immune system might ignore microorganism at one anatomical site but react to them in another
Inter host - microorganisms that cross species barriers may produce disease in one host but wont in another
Define: zoonotic , zoonoses, reverse zoonoses
Zoonotic = infections from animals
Zoonoses (animals to human) reverse (humans to animals)
___ % of newly emerging human infections are zoonoses
___% of all human pathogens are zoonotic
75 and 60
Why is Ebola symtomless in fruit bats but is highly virulent in humans
They have diff interferons system:
- innate - bats have constitutive interferon activity that suppresses viral infections
- adaptive - large naive antibody repertoires which done require rapid afinity maturation
Why is reverse zoonoses bad
Animal to human (we adapt)
Human back to animal -> emergence of new variants
What are some features of virus mutations?
- enhance transmission
- enhance virulence factors
- enhance immune evasion
What are the current zoonotic pandemics/threats
- H1N1influenzza
- HIV
- SARS CoV-1
- H1N1 swine flu
- MERS CoV
- Ebola
- Zika
- SARS CoV-2
What is CFRs and what do they tell us
Case fatality rate
- influence perception of risk vs hazard
Give one example of when zoonotic microorganisms benefited human health
- cowpox protects against small pox
Why are some vaccines successful and some not?
eradicated the pathogen bc it can only affect humans (once wiped out in humans it can no longer survive bc no hosts to switch to)
3 ways of using microorganisms for vaccination (pros and cons)
- Live-attenuated - strong, carry risk for immunocompromised people
- Dead or subunit - safer but don’t work as well
- Viral vectors - genetically engineer a benign microorganism to deliver a component
What is the hygiene hypothesis?
evolved to deal w infections, if there is no infections to fight it might become chaotic as they dont have purpose. Our immune system ‘expects’ to be challenged and may become dysregulated if not exposed to microorganisms
