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Flashcards in BASIC MICRO Deck (94)
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1

Which spirochete can you identify with a Giemsa stain?

Borrelia

1

What stain uses carbol fuschin?

Zeehl Neelsen for acid fast organisms

1

What are the 7 catalase positive organisms?

Pseudomonas, Listeria, Aspergillus, Candida, E. coli, S. aureus, and Serratia

1

What 5 bugs have AB toxins?

C. diphtheriae (tropic for heart/nerves), Pseudomonas (exotoxin A), ETEC heat labile toxin (heat stable is NOT AB toxin), Vibrio cholerae, B. pertussis (the pertussis toxin)

1

Which bacteria contains a toxin that cleaves phospholipid C causing myonecrosis and hemolysis?

Clostridium perfringens; Alpha toxin

1

What lab test is used to test for Rheumatic fever?

Antistreptolysin O antibodies = "STREP WAS HERE"

1

What is the difference between F(+) plasmid and Hfr?

In F(+) ONLY plasmid (i.e. extrachromosomal DNA) can be transferred? In Hfr, BOTH plasmid and nearby CHROMOSOMAL DNA can be taken up by the copulating bacteria

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

Where will you find genes for A) endotoxin B) exotoxin

A = bacterial genome as LPS is an essential gene B) on plasmid or bacteriophage because these are accessory genes

5

What is the 100 day cough?

Pertussis

6

Which ETEC toxin decreases water and NaCl reabosorption from the gut?

Heat stable (activates guanylate cyclase)

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 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)

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

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

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

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