Opportunistic mycoses

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Opportunistic mycoses
By
Dr. Emad AbdElhameed Morad
Lecturer of Medical Microbiology and Immunology
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Candida
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Species

• Candida is present as normal flora in the mouth,
  GIT and vagina.
• Species include
• Candida albicans (the most important)
• Candida tropicalis
• Candida krusei
• Candida parapsilosis
• Candida glabrata
• Candida dubliniensis

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Morphology

• Gram positive, oval budding yeast cells.
• If buds fail to detach, they form pseudohyphae.
• Pseudohyphae are differentiated from true hyphae
  by the presence of constrictions at septations
  between the cells.
• But, Candida glabrata does not form pseudohyphae.

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Diseases

• In normal host, candida may cause
• Oral thrush or moniliasis (patches of creamy
  white exudate that cover the mucous membrane of
  the mouth).
• Vulvovaginal moniliasis itching and cheese
  appearing vaginal discharge.
• Rash in the skin folds of obese persons.
• Diaper rash.
• Paronychia of the nails (thickening and loss of
  the nails).

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Oral thrush
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Vulvovaginal moniliasis
Rash in the skin folds
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Diaper rash
Paronychia
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• In immunocompromised individuals such as
• Esophageal thrush.
• Chronic mucocutaneous candidiasis.
• Systemic or disseminated candidiasis (even to the
  eye).

AIDS
Diabetes mellitus
Malignancy
Corticosteroids
Defect in cell mediated immunity
Catheters
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Laboratory diagnosis

• Specimen according to the site of the lesion.
• Direct examination of Gram stained smear Gram
  positive oval budding yeast cells pseudohyphae.

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• Culture on SDA at 37 degree.
• Identification of candida on the plate is done
  by
• Morphology soft cream colored colonies with
  yeasty odor.
• Gram film Gram positive oval budding yeast
  cells.

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• Biochemical reactions to differentiate between
  Candida albicans and other species.
• Germ tube test Candida albicans forms germ tube
  when incubated in serum for 1 2 hour at 37
  degree.
• Chlamydospore formation Candida albicans forms
  chlamydospores on corn meal agar incubated at 30
  degree.
• Sugar fermentation Candida albicans ferment
  glucose and maltose with acid and gas production.
• Inoculation of the yeast on chromogenic agar
  each candida species produces a different color
  on this medium.

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Germ tube
Chlamydospores
CHROMagar
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Treatment

• Oral thrush fluconazole
• Cutaneous lesions nystatin and clotrimazole
  ointments.
• Mucocutaneous candidiasis ketoconazole
• Disseminated candidiasis amphotericin B

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GOOD LUCK