Bailey: Intro 2 Infec. and Struc. Flashcards
Bacterial responses to O2:
- ___ ____- must have O2 to grow
- ___ ____-cannot tolerate O2
- ___ ____-can grow w/ or w/out O2 (most medically important bacteria)
strict aerobes
obligate anaerobes
facultative anaerobes
Microbes that can grow w/ limited nutrients?
oligotrophs
Microbes that require some O2, but lower levels of O2?
microaerophiles
Microbes that grow well in mild temps (body temps)?
mesophiles
True or False:
Gram neg and Gram pos both have lipid membranes and Murein (peptidoglycan)
TRUE
Structure of Murein:
-cross linked peptides attached to N-_______ acid giving it strength
acetylmuramic
Structure of Murein: (Peptidoglycan)
-alternating N-______ acid and N-_______ acid
acetylmuramic
acetylglucosamine
Structure of Murein:
Gram pos binds _____ to D-ala
L-lys
-immune system knows the difference by pattern recognition receptors
Structure of Murein:
Gram neg binds _____ to D-ala
DAP
-immune system knows the difference by pattern recognition receptors
Biosynthesis of Murein begins in the ______
cytoplasm
Linking/connecting NAM to NAG takes place in the ______
periplasm
LPS (lipidpolysaccharide) is only on Gram ___
-the outer most lipid layer
negative
Teichoic acid is only on Gram ___
positive
Teichoic acid helps what?
rigidity
Lipoteichoic acid helps does what?
interacts with the cell membrane
Structure of LPS: Lipopolysaccaride
- ____ __= fatty acid attached to a phophorylated disaccaride(only in bac)
- _____ ____= very similar btw Gm neg bac but has sugars that are somewhat unique to bac
- ___ ____=highly variable repeating sugar subunits
lipid A
polysaccharide core
o-antigen
What is the main reason for the different antigenic specificities among Gm neg bacteria?
o-antigen
LPS induces _____ (localized but can become systemic at high levels) and can lead to septic shock at high levels (_____)
TNF-alpha
endotoxin
LPS, Teichoic acids, and peptidoglycan are examples of ____
PAMPs
Cells of the immune system recognize PAMPs using ____
PRRs (pattern recognition receptors)
Toll-like receptor 4 recognizes ____
LPS
Toll-like receptor 2 recognizes ___
peptidoglycan
Toll-like receptor 2 and 6 together recognize ____
teichoic acids
Pili (fimbriae)- involved in the ____ of bac to cells other surfaces on host
-_____(on tip of fimbriae)= specialized proteins that are more specifically developed for adherence (recognizes receptors on host which increases affinity)
attachment
adhesins
____ ___= pili with hollow tubes to pass genetic info to another bac (plasmids= antibiotic resistance)
sex pili
Type of flagella with one tail?
monotrichous
Type of flagella with a few tails at end?
lophotrichous
Type of flagella with many tails all over?
peritrichous
Flagella moving in a forward (CCW) movement ____
runs
Flagella moving in a backwards (CW) movement ____
tumbles
When flagella movement is directed it is what?
taxis
-they are motile
___ can be directed toward something good or away from something bad
taxis
_____= a substance that surrounds a cell
_____= it is a type of what is listed above that is well organized and firmly attached to the cell
_____=it is a type of what is listed above that is not well organized or firmly attached to a cell
glycocalyx
capsule (usually made of PS but can be MS or glycoproteins)
slime layer
These are beneficial to pathogens because they cause them to become large/bulky
- make is hard to recognize and for macrophages to phagocytos bac
- masks things the immune system cannot recognize
capsules
-sometimes necessary virulence factor
Can the immune system ever recognize a bac that has a capsule?
yes
Toll-like receptor ____ recognizes flagella
(sometimes the capsular polysaccharide can be recognized)
5
What happens when the immune system recognizes a microbe?
macrophages produce and release cytokines (which recruit more)
Serological designations:
-o antigen refers to what?
Gm negative
Serological designations:
-H antigen refers to what?
motile (flagellum)
Serological designations:
-K antigen refers to what?
capsules
Bacterial Pathogens can be classified into 2 broad classes. What are they?
opportunistic= rarely cause disease in healthy ppl primary= infection/disease in healthy ppl by adhere, colonize, invade, induce damage
What type of adherence does primary pathogens use?
specific adherence= irreversible/anchoring
–adhesins (usually found on fimbrae)
Why does streptococcus mutans only bind to tooth pellicles?
its adhesin (glucosyl transferase) binds to a specific salvitary protein in pellicle formation
An example of an adhesin not found on fimbrae but that is a complex glycoproetin commonly found in plasma and associated w/ mucosal surfaces?
fibronectin= bind by teicholic acids
_____ is the formation of stable population of microbes
- -is needed to replicate
- -limited by nutrient availability
colonization =must bring in nutrients 1. carrier mediated diffusion 2. phosphorylation linked transport 3. active transport
-
-
- when they colonize (E coli)
- when they invade (salmonella)
- producing toxin after colonization (E coli)
