bacteria

Question 1

Gram Staining

Answer 1

Gram positive bacteria have a singular membrane with thick peptidoglycan layer that is able to be stained by crystal violet.
Gram negative has a double membrane with a thin peptidoglycan layer. Does not stain.
Sometimes little relation.

Question 2

Virulence Factors

Answer 2

Adhesins: factors that recognize and help bind to target cells.
(EX:
FimH, attaches E. coli to mannose sugars on human cells.
Protein A: Produced by Staphylococcus, when intrinsic coag. Cascade begins binds to vWf to infect at wound site. Also binds to Fc domain of antibodies to inhibit immune response against Staph.)

Question 3

Toxins:

Answer 3

Virulence factor that facilitate bacterial growth and infection.
Hemolysins: Protein that lyse red blood cells. Releases iron for bacterial growth. (EX: S. Aureus)

Question 4

Siderophores:

Answer 4

Pathogen produced iron carrier that facilitate iron uptake by coordinating it with high affinity and specificity.

Question 5

Endotoxins:

Answer 5

Non-protein virulence factor.
(EX: Lipolysaccharides in gram-negaive bacteria. Activates immune/ inflammation response through TLR (Toll-like receptors). Can lead to higher oxidative stress and disseminated intravascular coagulation (DIC: activation of clotting and impaired fibrinolysis.)

Question 6

Biofilms:

Answer 6

Colonies attached to any surface. Many bacteria held together by matrix of DNA, protein, and debris. Dormant and difficult to treat. (EX: Dental Plaque)

Question 7

Resistance:

Answer 7

Mutation: (EX: Fluroquinolone mutation of DNA gyrase or topo IV enzymes.)
Metabolizing: Detoxifying the antibiotic, make the structure inactive. (EX: B-Lactamase: break 4 member ring of B-lactam antibiotics
Effluxing: Pump out antibiotic drugs.