BASIC MICRO Flashcards Preview

Small But Terrible > BASIC MICRO > Flashcards

Flashcards in BASIC MICRO Deck (94)
Loading flashcards...
1

What is generalized transduction?

When a lytic phage infects a cell and accidentally packages some bacterial DNA into its capsid and then transfers that to another bacterium

2

What type of transduction is a "packaging event" which type is an "excision event"?

Packaging event = generalized; Excision event = specialized

3

What toxin does Staphylococcus aureus use to cause food poisoning?

Enterotoxin

4

What agar do you grow fungi on?

Saboraud dextrose agar

5

What is the 100 day cough?

Pertussis

6

How does Lipid A (of LPS) cause DIC?

by activating tissue factor

7

What general kind of bacteria will have a positive quellung reaction?

Encapuslated bacteria (Quellung test is an anti-capsular antibody)

8

What toxin overactivates adenylate cyclase BY INHIBITING Gi?

Pertussis toxin

9

What phase of the bacterial growth curve do penicillins and cephalosporins affect? WHY?

The exponential/log phase; this is where peptidoglycan is actively being made, since these are Beta-lactams, this is the only time they can actually kill bacteria (when they are dividing)

10

What effect will adding deoxyribonuclease to a medium have on the process of transduction?

Nothing. Transduction involves the transfer of DNA via bacteriophages, thus the DNA will be located within the viral capsid, NOT in the media as in transformation and therefore it will not be degraded

11

What 4 bacteria contain virulence factors that inhibit protein synthesis?

Pseudomonas and Corynebacterium (inhibit EF-2) and Shigella nad EHEC ("nick" the ribosome by blocking addition of adenine into rRNA)

12

What agar do you use for Neisseria species?

Thayer Martin agar (VPN agar: vancomyin, polymyxin, and nystatin)

13

On what agar will E. coli grow in metallic green colonies?

EMB = Eosin methylene blue

14

What enzyme can you add to a medium to prevent transformation from occuring?

Deoxyribonuclease (cuts up DNA); transformation = uptake of free DNA

15

What is the dye in a Ziehl Neelsen stain?

Carbol fuschin

16

How do you know if a bug is a lactose fermenter based on its growth on ___________ agar?

Pink colonies on MacConkey agar

17

What cytokines are induced by LPS?

TNF and IL-1

18

What is Regan-Lowe agar used for?

Bordatella pertussis

19

Where will you find endotoxin?

Endotoxin is contained in the outer membrane of gram negatives

20

What is Loffler's media used for?

Corynebacterium diphtheriae

21

What 2 toxins does ETEC possess?

HEAT LABILE: activates adenylate cyclase and secretes chloride and H20 from gut. HEAT STABLE: overactivates guanylate cyclase and decreases H20 and NaCl resorption from gut

22

What toxin has a similar, and more severe, action to exotoxin A from Streptococcus pyogenes?

TSST-1; both are superantigens

23

What 2 bacteria contains toxins that inactivate elongation factor 2?

Corynebacterium diphtheriae and Pseudomonas aeruginosa

24

Which 2 toxins overactivate adenylate cyclase in the gut and promote water and chloride excretion? What is similar about their structure?

Cholera toxin (permanently activates) and ETEC heat labile toxin (both are AB toxins)

25

Where are you likely to find beta lactamases in a gram negative bacterium?

In the periplasm which is a space between the cytoplasm and the outer membrane

26

What bacteria has yellow granules?

Actinomyces israelii (they arent really made of sulfur)

27

What 2 toxins cleave SNARE proteins?

Tetanospasmin and Botulinum toxin

28

Why do you use conjugated vaccines?

Because if you only use the polysaccharide the only antibody produced would be IgM because a polysaccharide cannot be presented to Th cells

29

What are pili and fimbrae made of?

glycoproteins

30

What are 5 bugs that have received their virulence factors via specialized transduction?

Shiga-like toxin of EHEC, Botulinum toxin, Cholera toxin, Diphtheria toxin, and Erythrogenic toxin of Strep pyogenes