Exam 3 (Zoonoses, Hawmophilus, Listeria)

Question 1

Is Yersenia pestis G+ or G-?

Answer 1

G-

Question 2

What organism is known for the plague/black death?

Answer 2

Yersenia pestis

Question 3

Once a human is infected with Yersenia pestis, it can cause what two forms of the disease?

Answer 3

• Bubonic: swollen lymph nodes can burst and lead to…

- Septicemic: within the blood stream

Question 4

What form of the plague is most contagious?

Answer 4

Pneumonic plague

Question 5

The plague spread from human to human is then called….

Answer 5

demic plague

Question 6

Francisella tularenis
Gram:
Epidemiology:

Answer 6

Gram: G-
Epidemiology: opportunistic zoonosis

Question 7

Virulence Factor of Francisella tularenis?

Answer 7

• intracellular growth in macrophages

- prevents phagolysosome fusion -> bacteremia

Question 8

What is rabbit or tick fever?

Answer 8

• ulceroglandular and oculoglandular tularemia

- pulmonary tularemia

Question 9

Brucella
Gram:
Epidemiology: (what specific organism?)

Answer 9

Gram: G-
Epidemiology: opportunistic zoonosis by B. melitensis

Question 10

How does “Undulant Fever” from B. melitensis start?

Answer 10

-organism penetrates mucus membranes and carries to heart and other organs via lymphatic system and resist phagocytic killing

Question 11

Is Haemophilus influenzae G+ or G-?

Answer 11

G-

Question 12

H. influenzae is frequently part of ________ flora and has __ O-antigen serotypes with type __ most virulent

Answer 12

• oral
• 6 (a-f)
• b

Question 13

What is the main virulence factor of H. influenzae?

Answer 13

capsule b (the most virulent O-antigen serotype)

Question 14

Conjugated vaccine against capsule b polysaccharides of H. influenzae stimulates production of what antibodies?

Answer 14

IgG

Question 15

What was the most common cause of bacterial meningitis in preschool children before 1987?

Answer 15

H. influenzae type b

Question 16

In unvaccinated children, encapsulated strains of _______________ can cause systemic diseases like __________, _________, __________, and ________.

Answer 16

• H. influenzae
• meningitis
• septicemia
• cellulitis
• epiglottitis

Question 17

Epidemiology of Haemophilus influenzae?

Answer 17

• aerosol transmission

- respiratory tract in elderly

Question 18

Legionella pneumophila
Gram:
Growth temp:
Resistant to:

Answer 18

Gram: G-
Growth temp: up to 46 C
Resistant to: chlorine and other biocides

Question 19

What is the main virulence factor of Legionnaire’s disease?

Answer 19

Legionella pneumophila

-inhibition of phagosomal fusion allows for growth within the ER of alveolar macrophages

Question 20

Transmission method of Legionella pneumophila?

Answer 20

-aerosol from water sources (from amoeba)

Question 21

Symptoms of legionnaires’ disease?

Answer 21

• severe pneumonia
• necrotic abscesses
• *especially in immune compromised and elderly pts**

Question 22

Is Listeria monocytogenes G+ or G-?

Answer 22

G+

Question 23

L. monocytogenes is resistant to what three things?

Answer 23

• acid
• cold
• salt

Question 24

What is the mechanism of action of listeriolysin O in L. monocytogenes?

Answer 24

• acid activated hemolysin for beta-hemolysis

- is a pore forming toxin that allows for phagosome escape

Question 25

What pathogen is associated with food borne illnesses even when kept in cold temps?

Answer 25

Listeria monocytogenes

Question 26

How do L. monocytogenes bacteria enter host cells?

Answer 26

Enter through M cells of digestive tract, are engulfed by macrophages, inhibit phagosome fusion, exit macrophage, enter host cells via endocytosis, move from cell to cell by actin filaments

Question 27

Mutant listeria lacking lysteriolysin can be killed with what kind of immune response?

Answer 27

CD4+ T cells binding to MHC Class 2 receptors on macrophages

-bacteria are in a phagosome

Question 28

Wild type listeria with lysteriolysin can be with what kind of immune response?

Answer 28

CD8+ T cells binding to MHC Class 1 receptors on the infected cell
-bacteria are not in a phagosome

Question 29

Listeria monocytogenes infections are most commonly seen in….

Answer 29

• immunocompromised pts
• neonates
• elderly
• pregnant women
• from contaminated food