Basic bacteriology

Question 1

What components of the cell wall and outer membrane induce TNF and IL-1?

Answer 1

Lipoteichoic acid (cell wall is major surface antigen)

Lipid A (O polysaccharide)

Question 2

Chocolate agar and factors

Answer 2

H. flu

Must include Factor V (NAD) and Factor X (hematin)

Question 3

Thayer Martin agar

Answer 3

Neisseria

Question 4

MacConkey agar

Answer 4

Lactose-fermenting enterics turn PINK

Enterobacter, E. Coli, Klebsiella

Question 5

EMB agar

Answer 5

E. coli

Colonies form green metallic sheen

Question 6

Charcoal yeast extract agar with cysteine and iron

Answer 6

Legionella

Question 7

Obligate intracellular

Answer 7

Rickettsia, Chlamydia, Coxiella

Rely on host ATP

Question 8

Encapsulated bacteria vaccines

Answer 8

Polysaccharide capsule is conjugated to a carrier protein (Diptheria toxin), promotes T cell activation and class switching

Pneumococcal, H. flu, Meningococcal

Question 9

Catalase + organisms

Answer 9

Nocardia, Pseudomonas, Listeria, Aspergillus, Candida, E. coli, Staph, Serratia

Question 10

Protein A

Answer 10

Binds Fc region of IgG

S. aureus

Question 11

IgA protease

Answer 11

cleaves IgA

SHiN (Strep pneumo, H flu, Neisseria)

Question 12

M protein

Answer 12

Prevent phagocytosis

Group A strep

Question 13

Diptheria toxin

Answer 13

inactivate elongation-factor 2

Question 14

Pseudomonas toxin

Answer 14

Exotoxin A

inactivate elongation-factor 2

Question 15

Shigella toxin

Answer 15

Shiga

inactivate 60S ribosome by removing adenine from tRNA

causes HUS (enhances cytokine release)

Question 16

EHEC toxin

Answer 16

Shiga-like toxin

inactivate 60S ribosome by removing adenine from tRNA

causes HUS (enhances cytokine release)

Question 17

ETEC toxin

Answer 17

heat-labile = incr. cAMP –> incr. Cl secretion

heat-stable = incr. cGMP –> decr. resorption

Question 18

Bacillus anthracis toxin

Answer 18

Edema toxin

increased cAMP

Question 19

Vibrio cholerae toxin

Answer 19

Cholera toxin

overactivates adenylate cyclase (incr. cAMP), incr. Gs

incr. Cl secretion

Question 20

Pertussis toxin

Answer 20

overactivates adenylate cyclase, disables Gi

impaired phagocytosis

Question 21

C. perfringens toxin

Answer 21

alpha toxin

Phospholipase/lecithinase –> myonecrosis

Question 22

Strep pyogenes

Answer 22

Streptolysin O

degrades cell membrane, lyses RBCs, contributes to B-hemolysis

Question 23

Transformation

Answer 23

ability to take up naked DNA from environment

SHiN bacteria

prevent by adding deoxyribonuclease

Question 24

Transposition

Answer 24

Segment of DNA moves from one location in the genome to another

Allows for DNA to move from plasmid to chromosome

Question 25

Transduction

Answer 25

Phage moves DNA from one bacteria to another

Lysogenic phages contain DNA for 5 toxins

Shiga-like toxin
Botulinum
Cholera
Diphtheria
Strep pyogenes