Section 5: gram positive non-endospore forming bacilli

Question 1

What are the characteristics of G+ non-endospore forming bacilli?

Answer 1

diphtheroid due to characteristic micrscopic morphology

club shaped and arranged to form V-shapes or palisades

Question 2

Propionibacterium acnes

Answer 2

aerotolerant
part of normal skin flora
produces lipases that split fatty acids from skin lipids, the fatty acids produce tissue inflammation and contribute to acne

Question 3

Which toxin fragment of corynebacterium diptheriae is responsible for necrotizing and neurotoxic effects?

Answer 3

toxin fragment A

Question 4

Corynebacterium diphtheriae

Answer 4

club shaped pleomorphic rod
facultative anaerobe
uneven stain due to volutin granules (storage granules full of phosphate)

Question 5

Symptoms of corynebacterium diphtheriae

Answer 5

mild sore throat and fever
whitish gray membrane composed of clotted blood, epithelial cells, and leukocytes forms in throat
toxin produces can cause nerve damage
membrane can become detached and obstruct airway=suffocation
toxin absorbed in bloodstream results in distant toxic damage

Question 6

Listeria monocytogenes

Answer 6

G+
small
motile (at 22-28 not 37C)
can grow at 4C (refrigerator)
Beta hemolytic
produces endotoxin

Question 7

What is the pathogenesis of listeria monocytogenes?

Answer 7

ingested in contaminated food
invade epithelial lining
normally cell mediated immune system eliminates infection before spread
immunocompromised and neonates at high risk