Gram positive non-spore forming rods

Question 1

What lab findings are useful to help diagnose other corynebacterium diptheroids (C. xerosis and D. hofmanli)?

Answer 1

colonies appear more regular than C. Diptheriae

Question 2

What is the morphology of corynebacterium diptheroids (C. xerosis and C. hofmanli)?

Answer 2

rods

Question 3

What are the clinical manifestations of other corynebacterium diptheroids (C. xerosis and C. hofmanli)?

Answer 3

acne, otherwise not pathogenic (compare C. diptheriae).

Question 4

Identify relevant epedemiology and risk factors associated with Listeria monocytogenes. (2)

Answer 4

newborn babies and immunocompromised at increased risk.

Question 5

T/F: Symptoms of diphtheria include pseudomembranous, pharyngitis, lymphadenopathy, and hematuria.

Answer 5

false. does not cause hematuria.

Question 6

How is Listeria monocytogenes transmitted? (3)

Answer 6

vertically (across the placenta). During childbirth from mother to child. Eating contaminated food.

Question 7

What are the clinical manifestations of Corynebacterium diphtheriae? (3)

Answer 7

gray pseudomembrane along airway will bleed if disturbed and obstruct airway. If toxin enters bloodstream: myocarditis, circulatory collapse, weakness and paralysis of cranial nerves

Question 8

What lab findings are useful to help diagnose Listeria monocytogenes? (5)

Answer 8

small gray colony with narrow zone of betahemolysis on blood agar; tumbling mobility on wet mount; V or L shaped arrangement; gram positive; cold growth

Question 9

How does Corynebacterium diptheriae gram stain?

Answer 9

positive

Question 10

How does Listeria monocytogenes gram stain?

Answer 10

positive

Question 11

What lab findings are useful to help diagnose Corynebacterium diphteriae? (5)

Answer 11

black colonies with brown halos form on a tellurite plate; club shaped gram positive rods; granules (volutin) produced on Loeffler’s medium; aerobic; non-spore forming.

Question 12

What is the morphology of Listeria monocytogenes?

Answer 12

small rod

Question 13

Identify the major virulence/toxicity factors associated with Corynebacterium diphtheriae. (2)

Answer 13

a-b toxin kills surrounding tissue by inhibiting synthesis of ADP ribosylation elongation factor 2. Toxic strains can transform formerly non-toxic strains into toxic strains.

Question 14

What are the clincal manifestations of Listeria monocytogenes? (2)

Answer 14

meningitis and sepsis in neonates and immunocompromised individuals.

Question 15

What are the major reservoirs for Listeria monocytogenes? (4)

Answer 15

animals or animal feces; unpasteurized dairy; vegetables; soil

Question 16

What is the major reservoir for Corynebacterium diphtheriae?

Answer 16

humans are the only natural host.

Question 17

What is the morpholog of Corynebcterium diphtheriae? What real world object do they resemble?

Answer 17

rod. club shaped

Question 18

How do the corynebacterium-diptheroids (C. xerosis and C. hofmali) gram stain?

Answer 18

positive

Question 19

Identify the major virulence/toxicity factors associated with Listeria monocytogenes. (3)

Answer 19

listeriolysin O (a beta-hemolysin) can degrade cell membranes, causing lysis. can grow intracellularly in macrophages. Can grow in cold conditions.

Question 20

How is Corynebacterium diphtheriae transmitted?

Answer 20

respiratory droplets

Question 21

Name the urgent, pathognomic, clinical finding associated with Corynebacterium diphtheriae.

Answer 21

gray pseudomembrane on pharynx is a medical emergency

Question 22

What is the “most common” associated with Listeria monocytogenes? (2)

Answer 22

most common cause of meningitis in renal transplant patients and adults with cancer.

Question 23

ABCDEFG of diphtheria

Answer 23

ADP ribosylation, Beta-prophage, Corynebacterium, Diphtheriae, EF-2, Granules