Medical MycologyOpportunistic Mycoses

Hugh B. Fackrell

Filename: Fungi_opport.ppt

Mycoses & Mytoxicosis

• Mycoses fungal infections

• Mycotoxicosis- intoxicaton

Fungal Diseases

• Mycoses -Colonization of the host

• Mycotoxicosis

• Hypersensitivity

Fungal Infections

• Opportunistic Infections

• Superficial fungal infections

• Cutaneous Mycoses

• Subcutaneous Mycoses

• Systemic Mycoses

Host Defense Factors

• Intact skin

• long chain fatty acids

• pH

• Bacterial antagonism

• stratum corneum desiccated

• epithelial cell turnover rate (0.5 kg/yr)

• Mucous membranes

• ciliated

• antimicrobials

• Immunological competence

Fungal Entry

• Rarely cause disease in healthy person
  • many host defenses

• Commensal
  • Candida albicans
  • Malasseza fufur

• Underlying disorder
  • trauma
  • immunological deficiency
  • debilitating conditions

Disease Mechanisms of Fungi

• Endogenous

• Opportunistic
  • Iatrogenic
    ( indwelling lines catheters)

• Exogenous

• Opportunistic
  • inhalation

• Superficial
  • Trauma hygiene

• Cutaneous
  • trauma

• Subcutaneous
  • trauma

• Systemic
  • inhalation

Fungal Dissemination

• Breach in host defenses
  • endocrinopathies
  • immune disorders
  • iatrogenic

Must repair defect

Opportunistic Mycoses

• Pneumocystosis

• Candidiasis

• Aspergillosis

• Zygomycosis
  • Mucormycosis
  • Phycomycosis

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

Pneumocystosis Occurence

• Primarily AIDS

• Hospitalized infants who were premature and malnourished

• Elderly

• Cancer and organ transplant patients who are being treated with immunosuppressive drugs.

Pneumocystosis Treatment

• Trimethoprim - sulfamethoxazole

• Aerosolized pentamidine (particularly for AIDS patients)

Pneumocystosis Laboratory Diagnosis

• Sputum, lavage, Transbronchial aspirate, Brush biopsy, Open biopsy

• Microscopic - Stain appearance, Fluorescent antibody

Pneumocystis microscopy

CDC Website

Pneumocystosis Microscopy

CDC Website

Pneumocystis microscopyFluorescent antibody

CDC Website

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.

• Disseminated candidiasis
  • Systemically in gut, renal, pulmonary.

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)

PPT Slide

Chronic Mucocutaneous Candidiasis

PPT Slide

Disseminated Candidiasis: Kidney

Disseminated Candidiasis

CandidiasisLaboratory Diagnosis

Treatment, Prevention & Control

• Oral: nystatin, amphotericin B, gentian violet

• Enteritis:Ketoconazole

• Vaginitis:nystatin amphotericin B
  • suppositories

• Systemic: amphotericin B + 5 fluorocytosine

Aspergillosis

• Granulomatous lesions

• Secondary to other chronic diseases
  • tuberculosis,

• malignancy, steroid therapy, immuno-compromised.

Aspergillus

Aspergillus

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

AspergillosisLaboratory Diagnosis

• Tissue specimens directional branching of septate hyphae

• Confirmation Difficult
  • repeated specimens
  • hard to isolate
  • ubiquitous

Zygomycosis

• Mucormycosis

• Phycomycosis