EX2 Bacterial Infection and Bacterial Surface Structures - Bailey Flashcards
These must have oxygen to grow
strict aerobes
These cannot tolerate oxygen
obligate anaerobes
The can grow with or without oxygen (most medically important)
facultative anaerobes
These can grow with limited nutrients
oligotrophs
These require some oxygen, but lower levels of oxygen
microaerophiles
These grow will in mild temps (15-45°C)
mesophiles
What structure does the gram stain adhere to
murein = peptidoglycan
Which gram bacteria has a thick Murein layer and stains a dark purple/blue
gram +
What is the structure of Murein
N-acetylmuramic acid and N-acetylglucosamine chains cross linked via peptide bonds
What will recognize peptidoglycan
PRRs
What is the biosynthesis of Murein
NAG and NAM synthesied in the cytoplasm, then link into a chain and then shuttled to the periplasm, then it is cross-linked via a peptide bond
This is found only on gram positive bacteria, extending the the murein, and interacts with the cell membrane
teichoic acid
These are fatty acids attached to a phosphorylated disaccharide, a component of LPS
lipid A
LPS has this type of core, of which its sugars are unique to bacteria
polysaccharide
This is the highly variable repeating sugar subunit of LPS
O-antigen
O-antigen is the main reason for what
the different antigenic specificites amount gram(-) bacteria
LPS induces what, and is known as what
TNF-α and can lead to septic shock
ENDOTOXIN
TLR-4 recognizes what
LPS
TLR-2 recognizes what
peptidoglycan
TLR-2 and TLR-6 together recognize what
teichoic acids
This is involved in the attachment of bacteria to cells and other surfaces; can also be used for gene transfer (antibiotic resistance)
pili (fimbriae)
[sex pili]
These are specialized proteins that are located on the tip of fimbriae
adhesions; specifically developed for adhesion
This is the term for when multiple flagella are located at one end of the bacterium
lophotrichous
This is the term for when multiple flagella are located all over the bacterium
peritrichous
What are the three components of a flagella and what is the portion you can see
filament (can see this)
hook
rod
True or False
Flagella move the bacterium in a corkscrew like pattern
True
The bacterium moves through a period of what, with CCW or CW being the main movement direction
runs and tumbles
CCW
When movement is directed it is referred to as this
taxis
Taxis can be directed in which way
toward something good or away from something bad
This is a substance that surrounds a cell
glycocalyx
A glycocalyx that is well organized, firmly attached is called a what? it is usually made of polysaccharides, but can include monosaccharides and glycoproteins
capsule
A glycocalyx that is not well organized or firmly attached is called a what
slime layer
What role does a capsule play when it comes to an immune response
a capsule makes it harder for a macrophage to phagocytose
for some bacteria, it is a virulence factor
True or False
The immune system can recognize a bacterium that has a capsule
True; TLR-5
TLR-5 recognizes what
flagella (and capsules)
What happens when the immune system recognizes a microbe
the release of cytokines
O antigen always refers to what
LPS; gram (-)
What does O, H, and K antigens refer to
LPS
flagella
capsules
Bacterial pathogens can be classified into 2 broad classes
opportunistic and primary
True or False
Opportunistic bacteria rarely cause disease in individuals with intact immunological and anatomical defenses
True
These pathogens only cause disease if something goes wrong with the host
opportunistic
These pathogens are capable of establishing infection and causing disease in individuals with intact immune defenses
primary
Primary pathogens contain these
virulence determinants that allow them to adhere, colonize, invade, and induce damage
What must a pathogen do before it can colonize, invade, or otherwise affect the host tissue
adhere
What are the two types of adherence
non-specific
specific
This type of adherence is reversible and there are multiple ways to dock
non-specific
This type of adherence is irreversible and is anchoring
specific
Specific adhesion involves which substances and found where
adhesions
tips of fimbriae
In S. mutans, what is so special about the formation of a pellicle
the adhesion of glucose transferase which binds to a salivary protein that is involved in the formation
This is a complex multifunctional glycoprotein commonly found in plasma and associated with mucosal surfaces; an adhesion
fibronectin
S. pyogenes binds to fibronectin through the use of what
lipotechoic acids
What is a limiting factor in colonization
nutrient ability
What are the three methods of how bacteria take-up nutrients
carrier-mediated diffusion
phosphyorlation-linked transport
active transport
This type of nutrient take up involves a carrier protein that follows a concentration gradient
carrier-mediated diffusion
This type of nutrient take up involves a carrier protein as an enzyme that changes the nutrient (i.e. glucose to G6P)
phosphorylation-liked transport
This type of nutrient take up involves the use of ATP to create H+ concentration gradient which brings in H+ and lactose (for example)
active transport
This is often needed for pathogenesis, but it alone is not sufficient enough for pathogenesis; additional virulence determinants are needed
colonization
What are three examples of how additional virulence determinants are needed with colonization
induce changes in the host cell
incude damage upon invasion
produce toxin after colonization
How does E.coli induce tissue pathology upon colonization
colonization leads to actin polymerization
actin polymerization causes structural rearrangement of host cell
structural changes to host cell leads to loss of function
These are the most prominent mechanisms used to invade host tissue
hyaluronidase and collangenase
hylauronidase will degrade what
hyluronic acid; a common component of the ECM
collagenase will degrade what
collagen; an important component of connective tissue
True or False
Endotoxin is secreted
False; it is not secreted, it is on the surface of the bacterium; LPS
exotoxin is secreted
What does type 1 exotoxin target
membrane acting; stimulates transmembrane signals
what does type 2 exotoxin target
membrane damaging; creates pores
what does type 3 exotoxin target
intracellular effecters; gets into host cell and induces enzymatic activity
Pathogenesis (or damage to the host) is often regulated by what
microbial factors
The infectious organism uses with lytic viral infections, invasions damage host tissue, and toxin producing microbes, and what does the host response result in
phagocytes
cytotoxic T cells
