1. OPPORTUNISTIC MYCOSES
Sevtap Arikan, MD

2. OPPORTUNISTIC MYCOSES General features
CAUSATIVE AGENTS
Saprophyte in nature/found in normal flora
HOST
Immunosupressed /other risk factors

3. OPPORTUNISTIC MYCOSES
Candidiasis
Cryptococcosis
Aspergillosis
Zygomycosis
Other: Trichosporonosis, fusariosis, penicillosis……
***ANY fungus found in nature may give rise to opportunistic mycoses ***

4. CANDIDIASIS Most commonly encountered opportunistic mycoses worldwide
Cellular immunity protects against mucocutaneous candidiasis, neutrophiles protect against invasive candidiasis
Endogenous inf.
Etio: Candida spp. Most common:
1. C. albicans 2. C. tropicalis

5. MOST COMMONLY ISOLATED CANDIDA SPECIES
C. albicans
C. tropicalis
C. parapsilosis
C. kefyr
C. glabrata
C. krusei
C. guillermondii
C. lusitaniae

6. Candida MORPHOLOGICAL FEATURES
Micr. Budding yeast cells
Pseudohyphae, true hyphae
Macr. Creamy yeast colonies (SDA)
Germ tube (C. albicans, C. dubliniensis)
Chlamydospore (C. albicans, C. dubliniensis)
Identification Germ tube, fermentation and assimilation reactions

7. Candida PATHOGENICITY
Attachment (Germ tube is more adhesive than yeast cell)
Adherence to plastic surfaces (catheter, prosthetic valve..)
Protease
Phospholipase

8. CANDIDIASIS Risk factors
Physiological. Pregnancy, elderly, infancy
Traumatic. Burn, infection
Hematological. Cellular immune deficiency, AIDS, chronic granulamatous disease, aplastic anemia, leukemia, lymphoma...
Endocrinological. DM, hypoparathyroidism, Addison disease
Iatrogenic. Oral contraceptives, antibiotics, steroid, chemotherapy, catheter...

9. CANDIDIASIS Clinical manifestations-I
1. CUTANEOUS and SUBCUTANEOUS
Oral
Vaginal
Onychomycosis
Dermatitis
Diaper rash
Balanitis

10. CANDIDIASIS Clinical manifestations-II
2. SYSTEMIC
Peritonitis
Hepatosplenic
Endophthalmitis
Arthritis
Osteomyelitis
Menengitis
Skin lesions
Esophagitis
Pulmonary inf.
Cystitis
Pyelonephritis
Endocarditis
Myocarditis

11. CANDIDIASIS Clinical manifestations-III
3. CHRONIC MUCOCUTANEOUS
Candida inf. of skin and mucous membranes
Verrucose lesions
Impaired cellular immunity
Autosomal recessive trait
Hypoparathyroidism, iron deficiency

12. CANDIDIASIS Diagnosis
Direct micr.ic examination
Yeast cells, pseudohyphae, true hyphae
Culture
SDA, routine bacteriological media
Serology
Detection of mannan antigen
(ELISA, RIA, IF, latex agglutination)

13. CANDIDIASIS Treatment
CUTANEOUS
Topical antifungal: Ketoconazole, miconazole,
nystatin
SYSTEMIC
Amphotericin B
Fluconazole, itraconazole
CHRONIC MUCOCUTANEOUS
Transfer factor

14. CRYPTOCOCCOSIS Underlying cellular immunodeficiency (AIDS, lymphoma)
Exogenous inf.
Pathogenesis Inhalation of yeasts
Etio. Cryptococcus neoformans

15. Cryptococcus neoformans General properties
Natural reservoir Soil, bird droppings
Micr. Encapsulated yeast (India ink)
Macr. Creamy, mucoid colonies (SDA)
Serotypes A-D (most frequently A)
Pathogenicity factors
a. Capsule
b. Diphenol oxidase (+) (Bird seed agar/ caffeic acid medium)
c. Ability to grow at 37°C

16. CRYPTOCOCCOSIS Clinical manifestations
1. PULMONARY
Asymptomatic/flu-like/hilar lap/cavitation
2. DISSEMINATED
**Meningitis (acute/chronic)
Cryptococcoma
Skin lesions
Other

17. CRYPTOCOCCOSIS Diagnosis
Samples CSF, sputum, aspiration from skin lesion
Direct exam. India ink
Culture SDA
Serology*** Detection of capsule antigen in CSF and serum by latex agglutination test

18. CRYPTOCOCCOSIS Treatment
Amphotericin B (+ flucytosine)
Life-long fluconazole prophylaxis following primary treatment (in AIDS patients)

19. ASPERGILLOSIS Etio: Aspergillus spp.(most common:A. fumigatus)
Risc factors and pathogenesis
1. Immunosupression, DM..exogenous inf. (inhalation of spores)
2. Inhalation of spores by atopic host Hypersensitivity reactions (allergy)
3. Ingestion of products contaminated with Aspergillus toxins  Mycotoxicosis / hepatocellular and colon carcinoma

20. Aspergillus GENERAL FEATURES
Natural reservoir: air, soil
Pathogenicity factors: hypha, phospholipase
Infected tissue: vascular invasion, thrombus, infarct, bleeding
Macr: powdery mould colonies
(color of the spores varies from one species to other)
Micr: septate hyphae (dichotomous branching), vesicule, phialides, microconidia

21. ASPERGILLOSIS Clinical manifestations-I
I. ALLERGIC ASPERGILLOSIS
1. Asthma (Type I)
2. Allergic bronchopulmonary aspergillosis (Types I, III)
II. NONINVASIVE LOCAL COLONIZATION
1. Aspergilloma (Fungus ball) (lungs, paranasal sinuses)
2. Otomycosis (external otitis)
3. Onychomycosis
4. Eye inf. (conjunctival, corneal, intraocular)

22. ASPERGILLOSIS Clinical manifestations-II
III. INVASIVE ASPERGILLOSIS
1. Pulmonary
2. Disseminated: GIT, brain, liver, kidney, heart, skin, eye
IV. MYCOTOXICOSIS

23. ASPERGILLOSIS Diagnosis
Samples Sputum, BAL, tissue...
Direct exam. Septate hyphae and conidia in sputum; intravascular hyphae in tissue
Culture SDA (without cycloheximide)
(should grow at least in 2 cultures !)
Serology
Allergy (detection of specific IgE in serum--RAST)
Invasive inf. (detection of galaktomannan antigen in serum--ELISA)

24. ASPERGILLOSIS Treatment
ALLERGIC Steroid
ASPERGILLOMA (if symptomatic) Surgery, amphotericin B
LOCAL, SUPERFICIAL INF. Nystatin
INVASIVE INF.
Surgical debridement
Amphotericin B, itraconazole
***High mortality rate

25. ZYGOMYCOSIS Causative agents Rhizopus, Rhizomucor, Mucor...
Natural reservoir Air, water, soil
Risk factors Diabetic ketoacidosis, immunosuppression
Pathogenesis Inhalation of sporangiospores
Infected tissue vascular invasion, thrombus, infarct, bleeding

26. ZYGOMYCOSIS Clinical manifestations
I. RHINOCEREBRAL
Nose, paranasal sinuses, eye, brain and meninges are involved
Orbital cellulitis
II. THORACIC
Pulmonary lesions, parenchymal necrosis
III. LOCAL
Posttraumatic kidney inf.
Skin inf. following burn or surgery

27. ZYGOMYCOSIS Diagnosis
Samples Sputum, BAL, biopsy of paranasal sinuses..
Direct exam. Nonseptate, ribbon-like hyphae which branch at right angles, sporangium
Culture SDA (cotton candy appearence)

28. ZYGOMYCOSIS Treatment
Surgical debridement
Amphotericin B
***High mortality rate