• epidemiology
  • central USA (along mississippi river)
  • found in souil contaminated by birds or bat feces
• dimorphic fungus
• entry- inhaled spores in lung
• clinical manifestations
  • primary lung infection may be symptomatic in 5% lung lesion heals with calcification and fibrosis
  • chronic pneumonia and lung cavity
  • disseminate via bloodstream to all organs, esp. to immunocompromised host

• predisp. to dissemination
  • AIDS
  • chronic corticosteroid therapy
• dx
  • phagocytosed yeasts seen on Giemsa stain
  • culture and biopsy
  • urinary Ag for disseminated disease by RIA
  • complement fixation Ab (is cross reactive though with B dermatitidis)
• pathology- phagocytosed ovoid yeasts found within monocytes and histiocytes due to granulomatous reaction

• dimorphic fungi
• epidemiology- endemic in central and south america
• entry- inhaled spores enter the lung
• disseminates to mucus membrane, GI tract and skin
• pathology- yeast like mariner's wheel

• present as commensal on skin, Gi tract
  • most infections are endogenous
• predispositions
  • neutropenia
  • defective neutrophils
  • broad spec antibiotics
  • indwelling IV catheters

• superficial disease
  • mouth, esophagus, vagina
  • skin, nails
• chronic mucucutaneous candidiasis
  • associated with T cell immunocompromise and endocrine deficiency
  • skin, nails
  • oropharynx
• invasive disease (hematogenous spread)
  • blood
  • liver, spleen
  • kidneys
  • endophthalmitis
  • skin

• culture
• germ tube tests (inoculate in 50% serum and germ tube forms if C. albicans)- yeasts form hyphal outgrowth during 2-3 hrs of incubation in serum at 37 C
• biopsy for histopath
• investigational assays
  • D arabinotol
  • enolase
  • beta glucan
  • PCR

• epidemiology- ubiquitous mold in environment
• entry- spores inhaled into lungs
• dx- culture, biopsy

• allergic bronchopulmonary aspergillosis
  • asthma
  • central bronchiectasis
  • immediate skin HS to Aspergillus Ag's
  • Aspergillus percipitins
• aspergilloma (go to bv's, leading to ensanguination)
  • fungus ball in old cavity which may cause severe hemoptysis
• invasive aspergillosis
  • lungs, sinuses, and systemic infection causing infarction (eyes, CNS, skin, bone)

• narrow septated hyphae (unique factor) with acute angle branching
• prediliction for bv's (grow toward bv's), lead to thromboses and infarction

Response to therapy for invasive infection depends on return of neutrophil function.

• ubiquitous zygomycetes molds: some are
  • mucur
  • rhizopus
  • absidia
• predispositions
  • DM with acidosis
  • trauma, burns (breach barrier)
  • neutropenia
  • deforaxamine therapy (chelating agent)

• clinical manifestations
  • rhinocerebral infection in diabetic ketoacidosis
  • pneumonia in neutropenia
  • skin infections in burn and trauma
• dx- culture, biopsy
• pathology
  • broad non septated/coenocytic hyphae with right angle braching
  • prediliction for bv's, so can lead to infarction

• sinus infection depends on correction of acidosis (can develop ulcer)
• lung infection depends on return of neutrophil function

• caused bu Cryptococcus neoformans
• ecology
  • serotypes A and D (var. neoformans)- pigeon droppings
  • serotypes B (var. gatti)- debris under red gum tree
• predisposition (T cell defects)
  • AIDS
  • prolonged steroids
  • lymphoma

Prior to AIDS epidemic, in 50% of cases, they will have NO predispositions.

• pneumonia and lung cavity
• meningitis
• dissemination to
  • skin (umbilicated lesions)
  • eye
  • bone
  • prostate
  • brain

• India ink- defines capsule on wet mount
• culture any fluid such as sputum, blood, CSF, urine
• biopsy for histopathology
  • mucicarmine stains capsule
• polysaccharide Ag in blood, CSF (but cross rxn with T. beigelii)
• in AIDS patients, use chronic suppressive therapy

• taxonomically classified as fungi
• phylogenically related to fungi
  • cyst wall resembles fungal cell wall
  • homology of conserved
    • 16S rRNA (ascomycetes)
    • 5S rRNA (zygomycetes)
    • EF-3 (S cerevisiae)
• BUT, differences
  • no ergosterol in membrane
    • dont respond better to antifungal agents

• entry- resp. tract early in life
• manifestation
  • primary infection probably occurs at young age
  • dormancy and carrier state (awaken upon immunocompromise)
  • interstitial pneumonia (Pneumocystis pneumonia)
  • can disseminate outside lungs
• predisposition
  • AIDS patients with CD4 less than 200
  • bone marrow transplants

• dx
  • sputum
  • bronchoalveolar lavage or biopsy
  • Giemsa or Gomori stain- stain black
  • methenamine silver stain- stain black
  • specific fluorescent monoclonal Ab stain
• tx in AIDS
  • primary- when patient at risk (CD4 less than 200)
  • secondary- after patient had infection