Candidiasis M7'1

1
Candidiasis M7.1

• Candida albicans
• Occasionally other species
• C. tropicalis C. parapsilosis, C. krusei, C.
  glabrata,
• Commensal GI, oral, vagina (5-30)
• Skin for some non albicans species
• An endogenous infection, except
• Occasional genital (male vs female role)
• Occasional nosocomial

2
Precipitating factors (M7.2)

• Disease due to changes in circumstance
• Physiological
• Pregnancy, infancy, diabetes
• Trauma and barrier breaks
• Maceration (intertrigo, paronychia)
• IV catheters, gastrointestinal lesions
• Systemic immune status
• Diabetes, HIV, malignancy
• Neutrophils are effector cells but need T cells
• Microbial balance
• Use of antibiotics

3
Spectrum of disease (M7.3)

• Cutaneous
• Intertrigo, nappy rash (dont say diaper)
• Nails (? Dermatophytosis)
• Mucocutaneous
• Oral thrush
• Chronic mucocutaneous candidiasis
• Decreased cell mediated immune function
• Vaginal thrush (and balanitis)
• Estrogen associated vaginal infection
• Topical therapy
• Recurrent episodes, prolonged oral therapy
  (selection)
• Systemic / disseminated
• Candidaemia

4
Laboratory diagnosis (M7.4)

• Cutaneous and mucocutaneous
• Direct microscopy budding yeasts and
  pseudohyphae
• Culture
• Standard Sabs
• Gono media (colonies with feet!)
• Identification
• Germ tube (5 neg, C. dubliniensis)
• Morphology on cornmeal (Dalmau plate)
• Chromogenic media
• Others (auxanograms)
• How far and when?
• Clinical significance of isolate?

5
Laboratory Diagnosis (M7.5)

• Systemic / disseminated
• Blood cultures
• Can have low sensitivity and be slow
• Dedicated lysis centrifugation
• Non culture methods
• Badly needed
• Currently poor sens and spec

6
C. dubliniensis (M7.6)

• Similar morphology to C. albicans
• Germ tube , chlamydospores on CMT
• Chromogenic agar (dark green vs light bluegreen.
• Weak or no growth at 42oC
• 98 have rough growth on Staib / CA agar.
• An increasingly recognised pathogen of HIV
  patients.