Bacterial cell structure Flashcards
What is the significance of the capsule on virulence?
Forms a protective coating on the outside of the bacterium, and can be used to escape from the immune system or help with adhesion
What is the benefit to the host of flagella?
They are strong immune activators
What do biofilms help with?
Greater adherence, antibiotic resistance, and immune system evasion
How do biofilms form?
When there are enough bacteria in close enough proximity sending out pheromones, they will start secreting a matrix substance that will eventually form around the entire colony
Inner membrane of bacterial envelopes
Made of a lipid bilayer
Cell wall of all bacteria
Made of peptidoglycan; sugar chains with attached short peptides.
Cell wall of Gram + bacteria
Multiple thick layers of peptidoglycan with teichoic and lipteichoic acid acting as antigenic determinants
Cell wall of Gram - bacteria
Thin, only a small number of peptidoglycan layers
Outer membrane
Lipid bilayer ONLY in Gram - bacteria that is made of LPS instead of phospholipids.
What are the components of the outer membrane?
Lipid A
Polysaccharide portion
O antigen polysaccharide side chain
What is the significance of lipid A?
Makes the LPS highly toxic
What is the significance of the O antigen?
Important antigenic marker
What do mycoplasma stimulate?
Anti-inflammatory responses in macrophage and dendritic cells
Spore formation in C. perfringens
Toxin in produced at the same time as spores
Spore formation in C. difficile
Spores are ingested, then they germinate in the large intestine and release toxin
