Adhesion to host cells

Question 1

What are the 6 structures bacteria can use to adhese to host cells

Answer 1

1. Flagella
2. Pili
3. Capsule (streptococcus sp)
4. Proteinaceous fibrils
5. S-layer proteins
6. Cell wall components (LPS for gram (-))

Question 2

What are adhesins

Answer 2

Molecules used by bacteria to bind to a host. LPS is used by E.coli to bind to epithelial cells, flagella is used by vibrio cholerea, staphylococcus aerus uses surface proteins,

Question 3

Describe type 1 fimbriae

Answer 3

Thin rigid rod like structures composed of protein, uniformly dispersed across the surface of the cell. Type 1 are mannose sensitve as a protein at their tip promotes adhesion to D-mannose residues on host cell surfaces.

Question 4

Describe type 5 fimbriae

Answer 4

Type 5 are thin rod like strcutures composed of protein called pilin. The N-terminal of pilin contains methylated residue. They are distributed evenly across the cell surface. Neisseria gonnorhea uses type 5 fimbriae to adhese to cells lining the urogential tract

Question 5

Describe CFA fimbriae

Answer 5

Some pathogenic strains of E.coli posses colonisation factor antigen fimbriae which allow bacteria to adhere to cells of the small intestine

Question 6

It is argued that probiotic bacteria may _____

Answer 6

It is argued that probiotic bacteria may compete for and block the attachment sites exploited by pathogens.