Bacteriology 1.4

Question 1

super antigens

Answer 1

force interaction between Th cells and AP cell, regardless of epitope.

exhausts Th cells, then they die.

dissemination thru diarrhea

Question 2

Staph Aureus

Answer 2

survives on skin
MRSA in hospital
community acquire

*MRSA like strains are responsible for about 20K deaths a year.

can attach well to host cells.

purposefully binds IgG, on the wrong side. prevents opsonization.

Question 3

toxins

Answer 3

.

Question 4

non-protein toxins

Answer 4

endotoxin activates TLR-4 causes septic shock, DIC, acute respiratory syndrome

Question 5

staph aureus toxins

Answer 5

toxic shock syndrome toxin- TSST-1, super absorbent tampons.

enterotoxins- food poisoning, fever- nausea.
exfoliative-
leukocidins- lyse WBCs
staphylokinase- mimics plaminogen activator
alpha toxin- alpha hemolysin

Question 6

Quorum sensing

Answer 6

bugs communicate thru auto inducers via threshold concentration, change bac behavior.

Acyl homoserine lactones

Question 7

staph aureus quorum sensing

Answer 7

AgrC= sensor kinase, recognizes auto inducer.

AgrA- response regulator, turns on genes. transcription factor.

Question 8

can quorum sensing machinery sense host hormones?

Answer 8

yes.

Question 9

pore-forming toxins

Answer 9

30% of all bacterial toxins
host cells lyse, in RBCs its called hemolysis.
form “halos” on blood agar plates

Question 10

membrane disrupting toxins

Answer 10

phospholipases- hydrolyzes lecithin

Question 11

Aerolysin

Answer 11

Inserts beta barrel to drill into host cell.

Question 12

listeria monocytogense

Answer 12

virulence controlled by PrfA, acts as regulon!!!

actin based motility!!!!! cool stuff. allows bacteria to move between cells avoiding detection.

Question 13

how are toxins internalized?

Question 14

CTX toxin