IB. Medical mycology | 25. Systemic and opportunistic mycosis.

Question 1

I. Systemic mycology
1. What are the features of systemic mycology?

Answer 1

• affect internal organs and may disseminate to multiple sites of the body
• infections that originate primarily in the lung but may spread to many organ
• are named as: deep mycoses
• are caused by pathogenic fungi, which can invade and cause disease in healthy or compromised hosts

Question 2

I. Systemic mycology
2. What are the causative agents of Systemic mycology?

Answer 2

1. Coccidioides immitis (Coccidioidomycosis)
2. Histoplasma capsulatum (Histoplasmosis)
3. Blastomyces dermatitidis (Blastomycosis)
4. Paracoccidioides brasiliensis (Paracoccidioidomycoisi)

CHPB

Question 3

I. Systemic mycology
3. What are the features of Coccidioides immitis (Coccidioidomycosis)?

Answer 3

• From inhaling spores usually in dust
• “Valley fever”– endemic to southern US and Mexico

Question 4

I. Systemic mycology
4. What are the features of Histoplasma capsulatum (Histoplasmosis)?

Answer 4

Lung infection from bats and birds

Question 5

I. Systemic mycology
5. What are the features of Blastomyces dermatitidis (Blastomycosis)?

Answer 5

From inhaling spores

Question 6

I. Systemic mycology
6. What are the features of Paracoccidioides brasiliensis (Paracoccidioidomycoisi)

Answer 6

Central and South America

Question 7

II. Opportunistic mycosis
1. What are the causative agents of Opportunistic mycosis?

Answer 7

1. Aspergilloses (Aspergillus fumigatus)
2. Cryptococcosis (Cryptococcus neoformans)
3. Mucormycosis (Mucor mucedo)
4. Candida albicans (yeast)

ACMC

Question 8

II. Opportunistic mycosis - Aspergilloses (Aspergillus fumigatus)
2A. What are the features of Aspergilloses (Aspergillus fumigatus)

Answer 8

1. is a mould
2. found in decaying vegetation
   - allergic bronchopulmonary aspergillosis
   - fungus ball -> the fungus grows in a preexisting
   cavity (tuberculoid cavity) -> surgical resection ->
3. invasive form -> spreading into the lung -> necrotising pneumonia -> dissemination to other organs (meningitis)

Question 9

II. Opportunistic mycosis - Aspergilloses (Aspergillus fumigatus)
2B. What is the mechanism of invasive form of Aspergilloses (Aspergillus fumigatus)?

Answer 9

Invasive form -> spreading into the lung -> necrotising pneumonia -> dissemination to other organs (meningitis)

Question 10

II. Opportunistic mycosis - Cryptococcosis (Cryptococcus neoformans)
3A. What are the main features of Cryptococcosis (Cryptococcus neoformans)?

Answer 10

1. is a yeast
2. may be isolated from fruit, milk, vegetation and soil
3. meningitis - found in very large numbers in bird feces

Question 11

II. Opportunistic mycosis - Mucormycosis (Mucor mucedo)
4A. What are the feature of Mucormycosis (Mucor mucedo)?

Answer 11

1. is a mould
2. localisation in the wall of the vessels -> prone to thrombosis -> possible ischemic necrosis throughout the body
3. Forms: rhinocerebral, pulmonary, cutan, gastro- intestinal, central nervous system

Question 12

II. Opportunistic mycosis - Mucormycosis (Mucor mucedo)
4B. What are the forms of Mucormycosis (Mucor mucedo)?

Answer 12

forms: rhinocerebral, pulmonary, cutan, gastro- intestinal, central nervous system

Question 13

II. Opportunistic mycosis - Candida albicans (yeast)
5A. What are the features of Candida albicans (yeast)?

Answer 13

• member of the normal flora of the: oral cavity, gastrointestine, vagina
• non albicans: C. krusei, C. lusitaniae, C. glabrata

Question 14

II. Opportunistic mycosis - Candida albicans (yeast)
5B. How does candida infection occur in patients with normal immunity?

Answer 14

• oral - soor
• vaginal
• interdigital candidiasis

Question 15

II. Opportunistic mycosis - Candida albicans (yeast)
5C. How does candida infection occur in patients with immundeficiency?

Answer 15

• disseminated oral candidiasis
• oesophagitis
• pneumonia
• nephritis
• endocarditis and sepsis
  (DOPEN)

Question 16

III. What are the treatments can we give mycosis?

Answer 16

1. Imidazoles ( local treatment, or given orally)
2. Triazoles (local treatment or given orally)
3. Polyene antifungal agents
   - Amphotericin B→ in systemic mycosis
   - Nystatin → mainly yeasts