Vol. IV - Microbiology

Question 1

H influenzae media

Answer 1

chocolate agar with Factor V and X (NAD and hematin)

Question 2

Neisseria media

Answer 2

Thayer-Martin: vancomycin, trimethoprim, colistin, nystatin

Question 3

Brucella, Francisella, Legionella, Pasteurella media

Answer 3

Charcoal yeast extract agar buffered with cysteine and iron

Question 4

Common aerobe examples

Answer 4

Nocardia, Pseudomonas, M. tb, Bortadella

Question 5

common anaerobe examples

Answer 5

Clostridium, Bacteroides, Fusobacterium, Actinomyces israelii

Question 6

Obligate intracellular common examples

Answer 6

Rickettsia, Chlamydia, Coxiella

Question 7

Yellow “sulfur” granules

Answer 7

Actinomyces israelii

Question 8

Golden yellow pigment

Answer 8

Staph aureus

Question 9

Blue green pigment

Answer 9

Pseudomonas aeruginosa

Question 10

Red pigment

Answer 10

Serratia marcescens

Question 11

Protein A

Answer 11

expressed by S. Aureus, binds IgG to prevent opsoniztion

Question 12

IgA protease species

Answer 12

S. pneumo, H influenzae typ b, Neisseria

Question 13

M protein

Answer 13

expressed by group A strep, prevents phagocytosis, may cause cross reactivity in rheumatic heart disease

Question 14

Diphtheria toxin mechanism

Answer 14

inactivates E2F

Question 15

Pseudomonas Exotoxin A mechanism

Answer 15

inactivates E2F

Question 16

Shiga toxin mechanism

Answer 16

inactivates 60S ribosome –> hemolytic uremic syndrome

also shiga-like in EHEC

Question 17

ETEC heat-labile toxin mechanism

Answer 17

activation of cAMP –> increased Cl secretion in gut –> loss of water

Question 18

ETEC heat stabile toxin

Answer 18

activation of cGMP –> decreased resorption of NaCL in gut

Question 19

anthrax toxin mechanism

Answer 19

mimics adenylate cyclase

Question 20

cholera toxin mechanism

Answer 20

over-activates adenylate cyclase via G_s

Question 21

Pertussis toxin mechanism

Answer 21

Inhibits G_i –> activation of adenlyte cyclase

Question 22

Tetanus toxin mechanism

Answer 22

cleaves SNAREs in Renshaw cells blocking release of inhibitory neurotransmitters (GABA and glycine)

Question 23

Botulinum toxin mechanism

Answer 23

cleaves SNAREs in motor neurons –> descending

paralysis

Question 24

Clostridium perfringens alpha toxin mechanism

Answer 24

phospholipase that degrades cell membranes

Question 25

S. pyogenes Streptolysin O mechanism

Answer 25

degrades cell membrane

Question 26

Toxic shock species

Answer 26

S. Aureus (TSST-1) and S. pyogenes (erythrogenic endotoxin A)