MYCOLAB PRELIMS

• CHARACTERISTICS OF FUNGI


  • Aerobic
  • Nucleated
  • Achlorophyllus
  • Sexual and or asexual reproduction
  • Cell wall contains chitin
• GROWTH REQUIREMENTS

  • Nutrients
  • pH
  • Temperature
  • Oxygen
  • Moisture
• MORPHOLOGICAL FORMS OF FUNGI

  • Yeast
  • Molds or Hyphae
• YEAST


  Single-celled structures with a thick cell wall
• YEAST


  Multiply asexually by budding
• HYPHAE


  Long, slender, branching tubes (3 to 10 microns)
• SEPTATE


  Hyphae with crosswalls
• COENOCYTIC OR NONSEPTATE


  No crosswalls present
• PIGMENTATION


  • Hyaline
  • Dematiaceous
• HYALINE


  No pigment
• Dematiaceous


  Dark colored (brown-black) hyphae and conidia (brown-black)
• MYCELIUM

  • Aerial mycelium
  • Vegetative mycelium
• AERIAL MYCELIUM


  • Also called reproductive mycelium
  • Above the agar surface
• VEGETATIVE MYCELIUM


  Extends intro substratum of agar and is responsible for absorbing water and nutrients
• STRUCTURES OF HYPHAE 


  • Rhizoids
  • Favic chandeliers
  • Nodular organs
  • Racquet hyphae
  • Spiral hyphae
• RHIZOIDS


  Root-like structures that may be located at the base of a sporangiophore
• FAVIC CHANDELIERS


  Resemble antlers of a deer
• NODULAR ORGANS


  Knots or twisted hyphae
• RACQUET HYPHAE


  Resemble tennis racquet with smaller end attached to larger end
• SPIRAL HYPHAE


  Coiled or corkscrew like turn in hyphae
• VEGETATIVE REPRODUCTIVE STRUCTURES


  • Sporangium
  • Conidia
  • Chlamydospores
  • Oidia
  • Arthrospores
• SPORANGIUM


  Sac-like structure
• CONIDIA 


  Produced at the tip of the hyphae
• Chlamydospores


  Cell enlarges and develops thick walls
• OIDIA


  Hyphal cells separate from one another to form flat ended asexual spores
• ARTHROSPORES


  Hyphal cells break apart
• FOUR APPROACHES TO LABORATORY DIAGNOSIS


  • Direct examination
  • Culture of the organism
  • DNA probe tests
  • Serologic tests
• CONIDIA


  Produced at the tip of the hyphae
• CHLAMYDOSPORES


  Cell enlarges and develops thick walls
• OIDIA


  Hyphal cells separate from on another to form flat ended asexual spores
• ARTHROSPORES


  Hyphal cells break apart
• FACTORS IDENTIFYING A MYCOTIC DISEASE


  1. Fungi are chronic
  2. The history obtained from the patient can be important.
  3. Such factors as diabetes, many types of cancers, alcoholism, recent surgery and administration of immunosuppressive agents/and or antibiotics predispose one to systemic mycoses
  4. An important tool in the diagnosis is the appearance of the organism in tissue
• SPOROTRICHOSIS


  Only fungus disease that has a clear-cut clinical picture
• CLINICAL PICTURE OF DISEASE PROCESS

  Little value in enabling one to diagnose a specific disease
• SPOROTRICHOSIS


  Caused by Sporothrix schenckii which results to a cording effect
• Appearance of the organism in tissue is an important tool in the diagnosis
• DIRECT EXAMINATION


  • Specimen (from a biopsy, pus sample, sputum specimen, or spinal fluid) is placed directly on a microscope slide.
  • Add a drop or two of KOH (10-20%)
  • Add coverslip
• KOH


  Clears away much of the tissue debris but does not break down fungal structures
• STAINED HISTOLOGY SLIDE


  • PAS (Periodic Acid Schiff)
  • GMS (Gomori's methenamine Silver)
• SIX WAYS THAT FUNGI MAY BE OBSERVED IN TISSUE

  1. Yeast cells
  2. Sporangia
  3. Hyphae
  4. Granules
  5. Fission bodies
  6. Combination of yeast cells and hyphae