Microbial Pathogenicity

Question 1

These are guidelines used to demonstrate that a specific pathogen causes specific disease symptoms

Answer 1

Koch’s Postulate

Question 2

What are 2 exceptions to Koch’s postulate?

Answer 2

1) Microbes that can’t be cultured (trepinoma pallidum)
2) pathogens that can be found in healthy subjects

Question 3

What are the key stages of microbial pathogenesis?

Answer 3

1) adherence to host cells
2) invasion of tissues
3) replication within host’s tissues
4) disease causing damage to host tissues (pathology)

similar to how viruses infect host cells

Question 4

What kind of virulence factor uses fimbriae to bind to host cells?

Answer 4

Neiserria gonorrhoeae

Question 5

What kind of virulence factor moves through mucus?

Answer 5

Flagella / helicobacter pylori (helicopter bacteria)

Question 6

What kind of virulence factor uses internalin related proteins (which is associated with foodborne pathogens) that allows bacteria to burrow into the cell?

Answer 6

Listeria monocytogenes

Question 7

An example of this is yersinia pestis, which solubilises metal bound to host proteins and transports it back to the bacteria

Answer 7

Siderophores

Question 8

These resist phagocytes by having an outer layer of protection.

Answer 8

Capsules

Question 9

What is streptococcus pneumoniae an example of?

Answer 9

A capsule virus

Question 10

These cause inflammation

Answer 10

Endotoxins

Question 11

These could be fatal

Answer 11

Exotoxins

Question 12

What are the 2 virulence factors associated with disease causing damage? (which is the last step of Microbial Pathogenesis)

Answer 12

Endotoxins
Exotoxins

Question 13

What are the 3 types of exotoxins?

Answer 13

Cytotoxins (streptococcus pyogenes) - causes beta haemolysis. neurotoxins (botulinum) - causes paralysis. eneterotoxins (shigella sp) - causes severe dysentery and diarrhoea