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Flashcards in Micro Deck (127)
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1

Chocolate Agar
- Factors V (NAD+) and X (hematin)

H. influenzae

2

Thayer-Martin Agar

Neisseria gonorrhoeae and meningitidis

3

Bordet Gengou Agar (potato) or Regan Lowe Medium (charcoal, blood, Abx)

Bordatella pertusssis

4

Tellurite Agar, Loffler Medium

C. diptheriae

5

Lowenstein-Jensen Agar

M. tuberculosis

6

Eaton Agar (requires cholesterol)

M. pneumoniae

7

MacConkey Agar
- Fermentation --> acid --> pink colonies

Lactose-fermenting enterics (E. coli, Klebsiella)

8

EMB Agar

E. coli

9

Charcoal yeast extract agar buffered with cysteine and iron

Legionella

10

Sabouraud Agar

Fungi

11

Yellow "sulfur" granules

Actinomyces israelii

12

Yellow pigment

Staph aureus

13

Blue-green pigment

Pseudomonas aeruginosa

14

Red pigment

Serratia marcescens

15

Protein A
- S. aureus

Binds Fc region of IgG --> prevents opsonization and phagocytosis

16

IgA Protease
- S. pneumo, H. flu type B, Neisseria

Cleaves IgA to colonize respiratory mucosa

17

M Protein
- Group A Strep

Prevents phagocytosis
- Molecular mimicry
- AI response in rheumatic fever

18

Type III Secretion System (Injectisome)
- Pseudomonas, Salmonella, Shigella, E. coli

Needle-like protein appendage facilitating direct delivery of toxins from certain gram negative bacteria to eukaryotic host cell

19

Transformation
- S. pneumo, Hib, Neisseria

Take up naked DNA from environment
- Add deoxyribonuclease --> degrades naked DNA --> no transformation seen

20

Conjugation

F+ = sex pilus, conjugation
F- = no plasmid
Hfr = F+ plasmid incorporated into bacterial chromosomal DNA (can bring flanking DNA)

21

Transposition

Segment of DNA jumps from one location to another (can bring flanking DNA)
- Ex. vanA gene from vancomycin-resistant Enterococcus to S. aureus

22

Generalized Transduction

Lytic phage infects bacterium --> cleavage of bacterial DNA --> parts of bacterial chromosomal DNA may become packaged in phage capsid --> phage infects another bacterium --> transfers genes

23

Specialized Transduction

Lysogenic phage infects bacterium --> viral DNA incorporates into bacterial chromosome --> phage DNA excised with some flanking bacterial genes --> DNA packaged into phage capsid --> infects another bacterium

24

Spore Forming Bacteria
- highly resistant to heat and chemicals
- dipicolinic acid in core
- must autoclave to kill

- Bacillus anthracis (anthrax)
- Bacilus cereus (food poisoning)
- C. botulinum (botulism)
- C. difficile (pseudomembranous colitis)
- C. perfringens (gas gangrene)
- C. tetani (tetanus)

25

C. diphtheriae
- Diphtheria toxin

ADP-ribosylation --> inactivates EF-2 --> no protein synthesis
- Pharyngitis with pseudomembranes in through and severe LAD (bull neck)

26

Pseudomonas aeruginosa
- Exotoxin A

ADP-ribosylation --> inactivates EF-2 --> no protein synthesis
- Host cell death

27

Shigella spp.
- Shiga toxin

Inactivates 60S ribosome by removing adenine from rRNA
- GI mucosal damage --> dysentery
- Enhances CK release --> HUS
- INVADES host cells

28

EHEC
- Shiga-like toxin

Inactivates 60S ribosome by removing adenine from rRNA
- Enhances CK release --> HUS (O156:H7)
- Does NOT invade host cells

29

ETEC
- Heat labile and heat stable toxin

Heat LABILE: overactivates adenylate cyclase --> increased cAMP --> increased Cl- secretion in gut and H2O efflux
Heat STABLE: overactivates guanylate cyclase --> increased cGMP --> decreased reabsorption of NaCl and H2O in gut
- Watery diarrhea

30

Bacillus anthracic
- Edema toxin

Mimics adenylate cyclase enzyme --> increased cAMP
- Edematous borders of black eschar in cutaneous anthrax