MYCO

• Types of Organisms


  • Prokaryote (Bacteria)
  • Eukaryote (Parasites
  • Fungi
  • Plants (uses chlorophyll to synthesize their food))
• Fungi


  Singular form = fungus<|>Plural = fungi

  
• Fungi


  • Eukaryotic
  • Chemotrophic - Energy comes from oxidation of inorganic molecules (iron, magnesium)
  • Achlorophyllous - Absence of chlorophyll, Obtain nutrient/food from environment
  • Has a rigid cell wall - Determine its shape, Mediate attachment of the fungus host cells (components: Carbohydrate layers which are the polysaccharides (chitin), glycoproteins and lipids)

  
• Primary component of bacteria

  Peptidoglycan
• Location of Fungi


  • Found in the environment (exogenous) - Most common in: soil, Other habitat: Water, Organic debris, Rotten human body/animals, or rotten wood

  
• Type of aerobe


  Obligate or facultative aerobes
• Cellular organelles


  • Nucleus
  • Nuclear membrane
  • Mitochondria
  • ER
  • Secretory Apparatus
• Secretory Apparatus


  The nutrients from organic substances are degraded to soluble nutrients by fungi's degrading enzyme secreted by their secretory apparatus
• Reproduction


  Sexual or Asexual - Structure: Spores (serves for reproduction) - The type of reproduction is depending on which spore they have

  
• Fungi spore = for reproduction, Bacteria spore = for virulence factor

  
• Mushrooms is a common fungus that is achlorophyllous, which they obtain their food through the environment by degrading wood
• Cell wall


  Has polysaccharide, specifically chitin - The chitin absorbs the primary stain even if decolorized or secondary stain is applied, Hence, the primary stain (crystal violet) will be retained because fungi are gram positive
• Yes, there is a fungi that is a normal flora, but only few like Candida, majority are found in the environment

  
• Wood


  Carbohydrate
• In comparison to bacteria, the reproduction of fungi can be both asexual or sexual
• The reproduction of bacteria is asexual, due to binary fission
• Yes, the virulence factor is important. Each virulence factor has specific infection.
• Virulence Factors of Medically Important Fungi

  • Aspergillus spp. (an opportunistic pathogen): Elastase-serine protease, Proteases, Toxins (Gliotoxin, fumagilin, helvolic acid), Elastase-metalloprotease, Aspartic acid proteinase, Aflatoxin, Catalase, Lysine biosynthesis, p-aminobenzoic acid synthesis
• Nagaraya has contamination of aflatoxin if the storage of peanut is not right, resulting in mold (green or black) formation in between the nut and the shell. Mold is okay but not to the extent you ingest the specific amount that has aflatoxin = toxicity
• Forms of Fungi


  • Yeast
  • Mold (AMAG)

  
• Incubation


  Yeast: 37°C, Mold: 21-25°C (room temp)
• Microscopic (Structure)


  Yeast cells (bigger)<|>Hyphae (Asexual)<|>Spore (Sexual)

  
• Macroscopic (Colonial morphology)


  Yeast: Soft, Pasty, Opaque<|>Mold: Filamentous (Cotton-like structure with different color)

  
• Dimorph


  Fungi with 2 distinct morphological feature (can grow either as yeast or mold depending on the environment) - Fungi in 37° = yeast will form, Fungi at room temperature (21-25 °C) = mold will form - Most dimorphic fungi are systemic mycosis

  
• 5 classifications of mycosis

  • Superficial
  • Cutaneous
  • Subcutaneous
  • Systemic
  • Opportunistic (Infects immunocompromised patients, Could be superficial, cutaneous, subcutaneous, or systemic)
• Polymorph


  In one culture, you can find 2 forms of fungi, mold and yeast, they simultaneously appear in one culture, regardless of their temperature - Fungi with more than one independent form in their life cycle

  
• Anamorph


  Asexually producing stage
• Teleomorph


  Sexually producing - If mycosis that have both Asexual and Sexual phases, like cryptococcus neoformans, it can have both Anamorph or Teleomorph, depending on their reproduction, however, they are given different names
• Tissue phase


  Yeast is called tissue phase because of its form called the spherule
• Workflow in Mycology


  • Specimen collection
  • Direct microscopic examination (Gram stain, KOH (10-20%), Histologic stain (PAS, India Ink))
  • Culture
  • Mycologic Identification
  • No biochemical test
  • AST (Macro: colonial morphology, Micro: Lactophenol blue (LPCB))
• Structure of Fungi


  • Thallus
  • Hyphae
  • Mycelium
  • Spore (asexual or sexual)
  • Nutritional requirement

  
• Thallus


  Entire Body of the mold
• Hyphae


  • Function (Aerial - Holds the spores, Aids in reproduction, Vegetative - Acquire nutrients from the environment (like roots))
  • Shape (Antler - Swollen or branching tips, Racquet - Enlarge, Club shaped, Spiral - Tightly Coiled, Rhizoid - Root-like structures)
  • Pigmentation (Hyaline hyphae - Moniliaceous (Non-pigmented), Dematiaceous hyphae - Phaeoid (Brown pigment due to melanin))
  • Presence of cross walls (Septate hyphae - Hyphae with cross wall, Coenocytic hyphae - Hyphae without cross walls (aseptate))

  
• When you see a mold in a loaf of bread, it is still okay to eat the bread, just remove the area visible mold, consequently, mold does not survive the gastrointestinal tract due to high acidity of the stomach
• Mycelium


  Filamentous mass of hyphae
• Types of Asexual Spores

  • Blastospores (Also known as Blastoconidia - Reproduction through budding that comes from the parent cell)
  • Chlamydospore (Also known as Chlamydoconidia - Thick walled spore formed by rounding and enlargement until a complete spore is formed, Three forms: Intercalary - within the hyphal segment, Sessile - side, Terminal - end)
  • Sporangiospore (A specialized vegetative structure, Formed within or enclosed within a sac and columella, Columella + sporangiospores = Sporangia - Sac-like structure filled with spores)
  • Conidiospore (A specialized vegetative structure with a distinct stalk and spore-bearing structure)

  
• Mycelium


  Mass of hyphae
• Types of asexual spores

  • Blastospores
  • Chlamydospore
  • Sporangiospore
  • Conidiospore
  • Arthrospore

  
• Blastospores


  • Also known as Blastoconidia
  • Reproduction through budding that comes from the parent cell
• Chlamydospore


  • Also known as Chlamydoconidia
  • Thick walled spore formed by rounding and enlargement until a complete spore is formed
  • Prominent
  • Three forms: Intercalary, Sessile, Terminal