Lecture 32: Microbial Pathogenicity Flashcards
Example of a virus pathogen
H1N1 influenza virus
Example of a fungi pathogen
Trichophyton spp.
Example of a prions pathogen
Kuru
influenza structure
single stranded RNA, enveloped
prion diseases work by
altering the folded formation of a healthy protein
Example of a protozoa pathogen
plasmodium spp.
Example of helminths pathogen
ancylostroma duodenale
Example of bacteria pathogen
Bacillus anthracis
gram positive bacteria trap
crystal violet stain in their thick peptidoglycan layer
gram positive bacteria are ….. in colour
purple
gram negative can’t trap
crystal violet stain in their thin peptidoglycan layer
Koch’s postulates
specific pathogens cause
a specific set of symptoms
exceptions to Koch’s postulates
treponema pallidum
- can’t be cultured
vibrio cholera
- pathogen can be found in healthy subjects
key stages of microbial pathogenesis:
1-
adherence to host cells
key stages of microbial pathogenesis:
2-
invasion of host tissue
key stages of microbial pathogenesis:
3-
replication within host tissues
key stages of microbial pathogenesis:
4-
disease causing damage to host tissue
Example of pathogens adherence to host cells
fimbriae binding to host cells
Example of pathogen invasion of host tissue
- motility to move through mucus using flagella
- proteins allowing pathogens through cell layers
example of diseases causing damage to the host
- endotoxins
- exotoxins
What are endotoxins?
they are lipopolysaccharides found in the outer membrane of gram negative bacteria
What do endotoxins do?
Elicit a strong immune response
What are the 3 types of exotoxins?
- cytotoxins
- neurotoxins
- enterotoxins
What do cytotoxins do?
cause the lysis of red blood cells
what do neurotoxins do?
causes paralysis
what do enterotoxins?
causes severe dystentery
