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Opportunistic and Deep Mycoses


Coccidioides immitis  (Southwest USA)
  • Located in desert soil
  • Characteristic structures
  • In the environment:  Arthroconidia
  • In the body:  Sphereules are pathognomonic




Blastomyces dermatitidis  (north central and southeast USA)
  • Associated with water



Lymphocutaneous Sporotrichosis





Mucocutaneous mycoses:  candida and dermatophytosis (get inflammatory response)
  • Candida albicans
  • Primary cutaneous candidiasis
  • Mucocutaneous candidiasis

Candidiasis
  • Wide range of infections
  • Candida albicans is the most virulent species
  • Candida spp. are common organisms of the skin, GI and UG tracts.
  • Candidiasis is a disease of compromised hosts.

Mucocutaneous (T CELL IMPAIRMENT)
  • Systems affected:
  • GI tract, skin, vagina
  • Onychomycosis
  • Keratitis
  • Symptoms:  Odynophagia, stridor, etc.
  • Diagnosis: white pseudomembranous plaques with hyphae, pseudohyphae, and budding yeast.
  • Groups at risk
  • HIV patients
  • Diabetics
  • Pregnancy
  • Age
  • Antibiotics
  • Steroids

Chronic mucocutaneous candidiasis – autoimmune polyendocrinopathy candidosis ectodermal dystrophy
  • Inherited disorder of CMI to candida along with polyendocrinopathies
  • Intractable candida infection of the mucocutaneous areas
  • Concurrent adrenal insufficiency and hypoparathyroidism
  • Type I diabetes
  • Hypothryroidism
  • Hypogonadism
  • Ectodermal dystrophy


Deeply invasive candidiasis (think CANCER)
  • Systems affected/ symptoms and signs:
  • Candidemia
  • Endocarditis – organism is sticky
  • Hepatosplenomegaly
  • Acute, shocklike syndrome
  • Renal dysfunction


At risk groups:  

  • Altered barriers
  • Neutropenia
  • Transplant
  • Hemodialysis
  • Pathogenesis
  • Adherence and colonization
  • Penetration through mucosal barriers and angioinvasions/access through catheters
  • Hematogenous spread
  • Replication yields necrosis +/- abscess with budding yeast and hyphae
  • Look at the fundus!  Candida goes to the eyes!

Virulence factors of Candida
  • Surface receptors
  • Cell wall is an immune modulator
  • Hydrolytic enzymes – e.g. acid protease, phospholipase
  • Host mimicry – e.g. C3D receptor
  • Dimorphism – makes it hardy!
  • Germ tube + species.








Superficial:  
  • Fungus confined to the stratum corneum or distal portions of hair
  • Tinea versicolor:  Malassezia furfur
  • Pigmentation changes due to fungal effect on melanocytes
  • Can cause folliculitis
  • Can cause fungemia in neonates with indwelling vascular catheters receiving total nutrition with lipids.
  • Malassezia furfur is a lipophilic yeast and it requires fatty acids to grow.