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USMLE Step 1-2015 > Microbiology > Flashcards

Flashcards in Microbiology Deck (82)
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1

Bugs that do not gram stain well

"These microbes may lack real color"
Treponema, Mycobacteria, Mycoplasma, Legionella, Rickettsia, Chlamydia

2

Giemsa stain

"Certain Bugs Really Try my Patience"
Chlamydia, Borrelia, Rickettsia, Trypanosomes, Plasmodium

3

PAS

Stains glycogen (used to diagnose whipple disease (T. Whippeli))

4

Ziehl-Neelsen (carbol fuchsin)

nocardia, mycobacteria (acid fast bacteria), cryptosporidium oocysts (protozoa)

5

India ink

Crytococus neoformans

6

Sliver stain

Fungi (e.g. pneumocystis), Legionella, H. pylori

7

Alternative to ziehl-neelsen for screening (more sensitive but less specific)

Auramine-Rhodamine stain

8

H influenzae media used for isolation?
Important media contents?

Chocolate agar, Factors V (NAD+) and X (hematin)

9

N gonorrhoeae, N meningitidis media used for isolation?Important media contents?

Thayer-Martin, Vancomycin (inhibits gram-positive organisms), Trimethoprim, Colistin (inhibits gram-negative organisms except neisseria), and Nystatin (inhibits fungi)
"Very Typically Cultures Neisseria"

10

B. pertussis media used for isolation? media contents?

1) Bordet-gengou agar (Bordet for bordetella)-->Potato
2) Regan-lowe medium (charcoal, blood, and antibiotic)

11

C diphtheria media used for isolation?

Tellurite agar, Loffler medium

12

M tuberculosis media used for isolation?

Lowenstein-Jensen agar

13

M. pneumoniae media used for isolation? important media contents?

Eaton agar, requires cholesterol

14

Lactose fermenting enterics media used for isolation? Important media contents/other?

MacConkey agar. Fermentation produces acid, causing colonies to turn pink

15

E. coli media used for isolation? Important media contents/other?

Eosin-methylene blue (EMB) agar. Colonies with green metallic sheen

16

Legionella media used for isolation?

Charcoal yeast extract agar buffered with cystein and iron

17

Fungi media used for isolation?

Sabourraud agar "sab's a fun guy"

18

Aerobes

Nocardia, Pseudomonas, MycoBacterium tuberculosis (Naggigng Pests Must Breathe)

19

Anaerobes

Fusobacterium, Clostridium, Bacteioides, and Actinomyces (Frankly Can't Breath Air)

20

What type of drug is ineffective against anaerobes?

Aminoglycosides b/c require O2 to enter into bacterial cell

21

4 key characteristics of anaerobes.

1) Suceptible to oxidative damage with no catalase/superoxide dismutase
2) Foul smelling (Short-chain fatty acids)
3) Difficult to culture
4) Produce gas in tissues (CO2 and H2)

22

Obligate intracellular

Rickettsia, CHlamydia, COxiella. Rely on host ATP "Stay inside (cells) when it is Really CHilly and COld"

23

Facultative intracellular

Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Legionella, Yersinia pestis (Some Nasty Bugs May Live FacultativeLY)

24

Encapsulated bacteria

SHiNE SKiS
Strep pneumoniae, H. influenzae type B, Neisseria Meningitidis, E. Coli, Salmonella, Kelbseilla pneumoniae, group B Strep

25

Urease positive organisms

Cryptococcus, H pylori, proteus, Ureaplasma, Nocardia, Kebsiella, S epidermidis, S saprophyticus (CHuck Norris hates PUNKSS)

26

Catalase positive organisms

Nocardia, Pseudomonas, Listeria, Aspergillus, Candida, E. coli, Staphylococci, Serratia (Cats Need PLACESS to hide)

27

Pigment producing bacteria:
Actinomyces israelii-->

Yellow "sulfur" granules

28

Pigment producing bacteria:
S. Auereus-->

Yellow pigment

29

Pigment producing bacteria:
Pseudomonase aeuroginosa-->

Blue-green pigment

30

Pigment producing bacteria:
Serratia marcescens-->

Red pigment