MICR223_L11_adhesion

What is the role of adhesion in bacterial pathogens?

Adhesion helps with colonization of tissues, toxin delivery, and biofilm formation.

What are P-pili?

P-pili are pyelonephritis-associated pili expressed by uropathogenic E. coli (UPEC) that facilitate adherence to urinary tract epithelium.

How do Type IV pili contribute to bacterial adhesion?

Type IV pili mediate binding to protein or glycolipid receptors on host cells and can promote internalization of bacteria.

What is the significance of single protein adhesins?

Single protein adhesins, like Invasin from Yersinia, bind to host receptors and can lead to bacterial internalization.

What does PapG do in the P-pilus structure?

PapG is the adhesin that binds to a receptor on the surface of human cells.

What is the function of PapC in P-pilus assembly?

PapC forms a channel in the outer membrane for the transport and assembly of P-pilus components.

What is the function of the PapD protein?

PapD is a chaperone protein that helps P-pilus components fold correctly and prevents degradation.

What basic mechanism do bacteria use for adhesion?

Bacteria use multi-component structures like pili or single protein adhesins for adhesion to host cells.

What are the diseases associated with Neisseria species?

N. meningitidis causes meningitis and septic shock, while N. gonorrhoeae causes gonorrhea.

What is the role of globoside in UPEC infection?

Globoside is the receptor on epithelial cells that P-pili of UPEC bind to for colonization.

How do Type IV pili facilitate twitching motility?

They extend and retract through the addition or removal of PilE subunits, allowing bacteria to move closer to host cells.

What happens when EPEC injects Tir into host cells?

Tir interacts with the bacterial adhesin intimin, forming pedestals that enhance adhesion to intestinal epithelium.

What is a key characteristic of the Type III secretion system?

It is a multi-protein complex that allows effector proteins to be injected into host cells.

What are the main components of a Type IV pilus?

PilE (main structural component), PilC (adhesin), and PilQ (channel in the outer membrane).

What is the outcome of Yersinia enterocolitica's interaction with M cells?

Invasin binds to beta1 integrin receptors, leading to internalization and localized inflammation.

What is the result of EPEC adhesion to host cells?

EPEC forms pedestals in intestinal epithelial cells that assist in persistent colonization.

How does Neisseria meningitidis penetrate epithelial cells?

It uses its Type IV pili to bind and internalize into human cells, leading to systemic infection.

What is the mechanism of UPEC's adaptation to antibiotics?

UPEC internalizes and forms intracellular biofilms that resist antibiotics and phagocytosis.

What kind of bacteria typically use Type I fimbriae for adhesion?

Gram-negative bacteria, like E. coli, typically use Type I fimbriae for adhesion to host cells.

What do 'pilicides' aim to do?

Pilicides are chemicals that inhibit P-pilus assembly, potentially serving as treatments for urinary tract infections.

What is the primary function of the Invasin protein?

Invasin facilitates the adherence and internalization of Yersinia into host cells.

What does the Tir protein induce in host cells upon interaction with intimin?

Tir interaction with intimin leads to actin polymerization and pedestal formation.

What structure do Type IV pili contribute to in Neisseria species?

Type IV pili contribute to the internalization and motility of Neisseria species, promoting its virulence.

How is adhesion to host cells mediated by EPEC different from Yersinia?

EPEC uses its own receptor (Tir) injected into host cells for adhesion, while Yersinia binds to host integrins.

How does ATP hydrolysis relate to Type IV pilus function?

ATP hydrolysis allows for the addition of new PilE subunits to the pilus, facilitating its extension.

What is the correlation between Tir expression and EPEC colonization?

Tir expression is critical for persistent colonization of the intestinal epithelium by EPEC.

Which bacterial pathogens are known to utilize Type III secretion systems?

EPEC, Salmonella, Shigella, and Yersinia are known to utilize Type III secretion systems.

How does the internalization of UPEC affect the human bladder?

UPEC forms biofilms within bladder cells, leading to chronic infections that are difficult to treat.

What role does globoside play in UPEC pathogenesis?

Globoside serves as a binding site for P-pili on bladder epithelial cells, facilitating colonization.