Microbial Toxins Flashcards Preview

MS1 - Disease & Defense > Microbial Toxins > Flashcards

Flashcards in Microbial Toxins Deck (26)
Loading flashcards...
1
Q

Infectious diseases cause about ________ of deaths worldwide.

A

1/3

2
Q

________ is the most toxic microbial toxin known.

A

Botulinum

3
Q

Polysaccharides make lipid A _________.

A

soluble

4
Q

Endotoxin can cause ___________.

A

(1) inflammation, by activating the complement cascade; (2) fibrinolysis, by activating Hagemen factor; (3) hypotension, by activating bradykinin (also through Hagemen); and (4) DIC, by activating TNF-alpha -> factor VII -> factor X

5
Q

Hemolysins are often __________.

A

pore-forming toxins

6
Q

Gram-positive bacteria tend to make ___________ more than Gram-negative bacteria.

A

pore-forming cytolysins

7
Q

Superantigens can cause _____________.

A

toxic-shock syndrome and necrotizing fasciitis

8
Q

Staphylococcus aureus and streptococcus pyogenes together produce __________.

A

more than 19 different superantigens

9
Q

Diphtheria infection leads to ___________.

A

bull neck, conjunctivitis, myocarditis, and colonization of the pharyngeal membrane

10
Q

How does diphtheria toxin kill cells?

A

It modifies EF-2 (elongation factor-2) and thereby inhibits protein synthesis.

11
Q

Diphtheria is only taken up by ___________.

A

susceptible cells–those with the membrane receptor for diphtheria toxin (epidermal growth factor receptor, EGFR)

12
Q

Diphtheria binds with its ___ subunit and kills with its ______ subunit.

A

B; A

13
Q

________ treat diphtheria.

A

Anti-toxin and erythromycin

14
Q

Diphtheria toxin and Pseudomonas aeruginosa exotoxin A both _________.

A

inhibit protein synthesis by transferring the ADP-ribose portion of NAD to EF-2

15
Q

Although they do the same thing inside cells, diphtheria toxin and P. aeruginosa toxins _________.

A

are not cross-reactive; they have different antigenic regions and affect different cells based on membrane-receptor affinity

16
Q

____________ all also inhibit protein synthesis, similar to diphtheria and P. aeruginosa toxin, but they do so by ________.

A

Shiga toxin, enterohemorrhagic E. coli toxin, and ricin; modifying the 60S subunit of eukaryotic ribosome

17
Q

Type III secretion is ____________.

A

injection directly into host cells through needles; common in Gram-negative bacteria

18
Q

Type VI secretion is _______________.

A

needle insertion into other bacteria

19
Q

Botulinum toxin works on __________, while tetanus toxin works on _________.

A

motor neurons; spinal interneurons

20
Q

Botulinum toxin is released by __________.

A

cell lysis

21
Q

Some exotoxins that degrade the extracellular matrix are _________.

A

hyaluronidase, collagenase, elastase, and streptokinase

22
Q

Although they both inhibit cell protein synthesis, diphtheria toxin and pseudomonas aeruginosa exotoxin act on ________.

A

different cells; PAE targets liver cells, and DT attacks heart, liver, and kidney cells

23
Q

The exotoxins that affect intracellular signaling pathways are __________.

A

Vibrio cholerae, E. coli, anthrax, C. diff, and B. pertussis

24
Q

Tetanus toxin inhibits ___________.

A

VAMP (and the subsequent release of vesicles)

25
Q

Staphylococcal enterotoxins and streptococcal exotoxins are both _________.

A

superantigens

26
Q

Diphtheria does not leave the __________.

A

respiratory tract or skin–only its toxin does

Decks in MS1 - Disease & Defense Class (59):