Spirochetes

• Spirochetes


  Spiral or helical bacteria which share some unique morphological and functional features
• Spirochetes

  • Motile by means of endoflagella
  • Demonstrated using Dark Field Microscopy
• Genera of veterinary importance

  • Borrelia
  • Leptospira
  • Brachyspira/ Serpulina
• Leptospires can survive in ponds, rivers, surface waters, moist soil and mud when environmental temperatures are warm
• Pathogenic leptospires can persist in the renal tubules or in the genital tract of carrier animals
• Leptospirosis- Horse

  Iridocyclitis ( periodic ophthalma or moon blindness
• Clearing agent which digests the proteinaceous host cell debris and leaves the s containing fungal cell wall

  Potassium hydroxide (KOH)
• Stains used to demonstrate the capsule of fungi

  India ink, Mucicarmine stain
• Agar media used for isolation and identification of fungi

  Sabouraud Dextrose Agar (SDA)
• Agar that promotes sporulation of fungi

  Potato Dextrose Agar (PDA)
• Stain that is used in wet mount preparation for microscopic examination of fungi

  Lactophenol Cotton Blue (LPCB)
• Fungi having both yeast and mold forms

  Dimorphic fungi
• Blastomyces dermatitidis

  • Lollipop-shaped conidia
• Candida albicans


  • White to tan colony on Sabouraud's dextrose agar
• Antifungal drugs used as treatment for systemic mycosis

  • Amphotericin B
  • Itraconazole
  • Fluconazole
  • Voriconazole
• Trichophyton rubrum


  • Pear-shaped microconidia produced at 30°C
• Microsporum canis

  • White suede-like colony with a pale yellow-brown reverse on Sabouraud's Dextrose agar
• Systemic mycoses (Aspergillus, Coccidi j'es, and Histoplasma)


  Primarily acquired via inhalation of spores
• Aspergillus fumigatus

  • Blue-green, powdery colony
• Aspergillus flavus

  • Cottony aerial mycelium when young, becomes yellow-green with sugary texture
• Rhizoferrin

  Siderophore which also provides iron to Rhizopus through a receptor-mediated, energy-dependent process
• Candida albicans

  Yeasty or bread-like odor
• Chromogenic media, such as CHROMagar


  Used in isolation and presumptive identification of Candida spp
• Dermatophytoses


  Ringworm
• Aflatoxin B1


  • Most potent among aflatoxin produced by Aspergillus fumigatus
• Gliotoxin


  • Virulence factor of Aspergillus fumigatus that inhibits oxidative burst of macrophage
• Sporothrix schencki

  • Cigar-shaped yeast
• Predisposition to Coccidioidomycosis

  • Immunocompromised state
  • Occupation (such as farming, construction)
  • Ethnicity (Filipinos, African Americans)
  • Pregnancy
• Ajellomyces dermatitidis


  Sexual form of Blastomyces dermatitidis