CRYPTOCOCCUS (SYSTEMIC MYCOSES)

Question 1

Describe Cryptococcosis spp.

Answer 1

• Cause of sub-acute or chronic mycotic infection of animals and humans known as cryptococcosis or European blastomycosis. * Domestic cats are frequently affected.

Question 2

What is the animal pathogen of Cryptococcosis spp.?

Answer 2

C. neoformans

Question 3

Describe the morphology and staining features of Cryptococcosis spp.

Answer 3

• Grows as yeast at room temperature and at 37 C
• Spherical shaped or ovoid with thick wall
• Pathogen develops a thick capsule

Question 4

What are the growth characteristics of Cryptococcosis spp.?

Answer 4

• Grow in common laboratory media at ambient and body temperature
• Grow in chocolate agar plate
• Colonies are mucoid, grayish white in color
• Use abundant amount of creatinine

Question 5

What are the biochemical features of Cryptococcosis spp.?

Answer 5

Grows well in diphenolic and polyphenolic compunds

Question 6

What is the variability of Cryptococcosis spp.?

Answer 6

4 antigenic types(A,B,C,D) based on capsular polysaccharides

Question 7

What are the reservoirs of Cryptococcosis spp.?

Answer 7

Dust and dirt, soil, dried pigeon droppings(rich in creatinine) and wood

Question 8

What is the transmission route of Cryptococcosis spp.?

Answer 8

Respiratory route

Question 9

Describe the pathogenesis of Cryptococcosis spp.

Answer 9

• Shown as a paranasal infection
• Pulmonary lesions (lungs), CNS involvement with neurologic signs (fungus metabolizes nitrogen-containing substances abundant in CSF)
• Eye involvements (chorioretinitis and blindness)
• Ulcerative lesions of mucus membranes(dogs & cats)
• Mastitis in cattle (gross swelling and hardening of the duct
• Granulomatous destruction of nasal turbinates, facial sinuses, osseous structures and meninges

Question 10

Give the host range of Cryptococcosis spp.

Answer 10

• dogs, cats, cattle, horses, pig and man (associated with immunosuppression, organ transplants, Hodgkin’s disease, AIDS)

Question 11

Give the virulence factors of Cryptococcosis spp.

Answer 11

Capsular polysaccharides

Question 12

What is the diagnostic method for C.?

Answer 12

Source of samples: Exudates, tracheobronchial washes and CSF

Question 13

What are the preferred culture media and substrates?

Answer 13

1. Blood agar
2. SDA

Question 14

How do you ID C.?

Answer 14

Microscopic exam of spinal fluid from lesions

Question 15

What are the treatment agents for C.?

Answer 15

• Fluconazole
• Ketoconazole
• Micronazole
• 5-fluorocytosine (5FC)

Question 16

C. can be disinfected by ?

Answer 16

Lime solution