Download Medical Mycology

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Medical Mycology
Opportunistic Mycoses
Hugh B. Fackrell
Filename: Fungi_opport.ppt
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Mycoses & Mytoxicosis
 Mycoses

fungal infections
Mycotoxicosis- intoxicaton
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Fungal Diseases
Mycoses -Colonization of the host
 Mycotoxicosis
 Hypersensitivity
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Fungal Infections
 Opportunistic
Infections
Superficial fungal infections
 Cutaneous Mycoses
 Subcutaneous Mycoses
 Systemic Mycoses
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Host Defense Factors

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Intact skin
long chain fatty acids
pH
Bacterial antagonism
stratum corneum
desiccated
epithelial cell turnover
rate (0.5 kg/yr)
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Mucous membranes
ciliated
antimicrobials
Immunological
competence
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Fungal Entry

Rarely cause disease in healthy person
– many host defenses
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Commensal
– Candida albicans
– Malasseza fufur
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Underlying disorder
– trauma
– immunological deficiency
– debilitating conditions
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Disease Mechanisms of Fungi

Endogenous
 Opportunistic
– Iatrogenic
( indwelling lines
catheters)
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Exogenous
 Opportunistic
– inhalation
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Superficial
– Trauma hygiene
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Cutaneous
– trauma
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Subcutaneous
– trauma
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Systemic
– inhalation
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Fungal Dissemination
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Breach in host defenses
– endocrinopathies
– immune disorders
– iatrogenic
Must repair defect
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Opportunistic Mycoses
Pneumocystosis
Candidiasis
 Aspergillosis
 Zygomycosis
– Mucormycosis
– Phycomycosis
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Pneumocystosis
Pneumocystis carinii - Thought to be a
protozoan but recent RNA analysis
shows it is a fungus.
Infections occur world wide, if symptoms
occur - mild respiratory. Childhood.
 Respiratory Infection

– interstitial pneumonitis with plasma cell
infiltrates
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Pneumocystosis
Occurence
Primarily AIDS
 Hospitalized infants who were premature
and malnourished
 Elderly
 Cancer and organ transplant patients who
are being treated with immunosuppressive
drugs.
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Pneumocystosis
Treatment
Trimethoprim - sulfamethoxazole
 Aerosolized pentamidine (particularly for AIDS
patients)
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Pneumocystosis
Laboratory Diagnosis
Sputum, lavage, Transbronchial aspirate,
Brush biopsy, Open biopsy
 Microscopic - Stain appearance, Fluorescent
antibody
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Pneumocystis microscopy
CDC Website
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Pneumocystosis Microscopy
CDC Website
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Pneumocystis microscopy
Fluorescent antibody
CDC Website
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Candidiasis

Candida albicans - normal flora of the mouth,
gut, vagina.
– Acute purulent inflammation with white patches.
– Heavy discharge in the mouth, vulvo-vaginal area, or
glans penis.

chronic mucocutaneous candidiasis
– in skin- moist areas axilla,perineum,nails.
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Disseminated candidiasis
– Systemically in gut, renal, pulmonary.
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Candidiasis
Usually indigenous flora (endogenous) but can be
infectious (exogenous) .
 Typical opportunist:
– normal flora disruption
– Birth control pills - vaginitis.
– Pregnancy
– Diabetes
– malignancy
– drugs corticosteroids Immunosuppressive drugs.
Broad spectrum oral antibiotics(gut)
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Chronic Mucocutaneous
Candidiasis
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Disseminated Candidiasis: Kidney
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Disseminated Candidiasis
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Candidiasis
Laboratory Diagnosis
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Treatment, Prevention
& Control
Oral: nystatin, amphotericin B, gentian violet
 Enteritis:Ketoconazole
 Vaginitis:nystatin amphotericin B

– suppositories
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Systemic: amphotericin B + 5 fluorocytosine
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Aspergillosis
 Granulomatous
lesions
Secondary to other chronic diseases
– tuberculosis,
 malignancy, steroid therapy, immunocompromised.
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Aspergillus
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Aspergillus
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Diseases caused by Aspergillus
Mycotoxicoses
– contaminated food
 Hypersensitivity pneumonitis
– (allergic bronchopulmonary disease)
 Secondary colonization
– no invasion of surrounding tissue
 Systemic mycoses
– invasion of multiple organs
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Aspergillosis
Laboratory Diagnosis
Tissue specimens
directional branching
of septate hyphae
 Confirmation Difficult
– repeated specimens
– hard to isolate
– ubiquitous
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Zygomycosis
Mucormycosis
 Phycomycosis
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