Vlahovic Micro 4

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Vlahovic Micro 4
2013-12-03 19:24:12
mycobacteria, what she asked in class
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  1. How histoplasmosos is introduced into the body
    • pathogenic fungi
    • systematic infection
    • infection associated with a geographic area or infested hazard site
    • inhalation of spores: number vs. resistance vs. virulence
    • exposure to a sufficient inoculum size
    • traumatic implantation of the inoculum directly into tissue 
  2. sources of infection
    • Geophilic - soil
    • Zoophilic - animals
    • Anthropophilic - human to human
  3. Ex of traumatic inoculation of fungi
    Madura foot-- walking in the tropics, it gets implanted in foot
  4. Example of a geographic area and a fungi
    • Ohio river Basin
    • is a patient who lives there or is in the region and is on immunosuppressants or RA drug, fungi is probably a problem
  5. Which things that are dimorphic, fungi
    • mold form @ room temperature
    • yeast for @ body temperature
  6. Ex of a dimorphic fungi
    • canidia albicans
    • budding yeast, filamentous hyphae, or intermediate
  7. Treatment of choice for a true systemic myosis
    • Amphotericin B -   “Amphoterrible”
    • highly toxic to kidneys
    • binds to sterols
  8. Candida albicans is part of normal flora?
    Yes: normal gastrointestinal flora
  9. Candiasis is called when infects the mouth
  10. Dermatophyte infections 
    • Fungi that cause infections of keratinized tissues, epidermis, hair, and nails
    • Most common skin infections seen worldwide
    • The only fungal infections which are contagious
    • Dermatophytes contain keratinase - digest keratin
    • inflammatory
  11. Generality of dermatoyphyte infections and know the 3 dermatophytces
    • Microsporum - attack hair & skin; hairs will fluoresce green under a Wood’s lamp
    • Trichophyton - attack hair, skin, & nails; hairs do not fluoresce ******
    • Epidermophyton - attack skin & nails
  12. What is the choice for tinea capitis tx. 
    • Oral liquid griseofulvin trt of choice with food; 4-6 weeks
    • Now most using Gris-Peg (ultramicrosized griseofulvin)No topical antifungals
    • Shampoo with Selenium sulfide (Selsun blue)
    • Most misdiagnosed: child with scaly scalp should presume to have tinea until proven otherwise
  13. Id reaction
    • = hypersensitivity to dermatophyte
    • a patient with athlete’s foot develops vesicles on fingers – due to circulating fungal antigens
    • Fungal infection of hand shows up on foot
    • treat the initial reaction, takes care of the Id
  14. The most common form of tinea pedis in interdigitial
    • T rubrum
    • 4th and 5th interdigital space
  15. The most common cause of nail fungus the dermatophytic
  16. Nystatin
    • can only be used as a powder and nothing else.
    • Cannot be oral or IV (toxic as IV!)
  17. Azoles are fungistatic
    • fungistatic= attach to cytochrome p-450 of fungi;
    • interfere with conversion of lanosterol to ergosterol;  
    • leads to defective cell membrane with altered permeability
  18. Drug class terbinafine belongs to
    Allylamines - Inhibit ergosterol biosynthesis; inhibits conversion of squalene and squalene builds up and is toxic; fungicidal
  19. What is orally given for dermatophyte infections—drug names
    Only a couple we talked about
    Oral and vs topical
    • Nystatin-- topical fro vaginal candidiasis and orally for yeast infections
    • Imidazoles-- fungistatic: miconazole, clotrimazole, ketoconazole
  20. gris-PEG
    • fungistatic
    • for onychomycosis
  21. Tinea nigra characteristics
    -Etiology = Hortaea werneckii (also known as Exophiala werneckii) or Stenella araguata

    -Distribution = warm climates, geophilic & anthropophilic, hyperhidrotics (excessive moisture), coastal states of the US.

    -Exposure to soil, sewage, wood, compost

    -Dimorphic fungus - produces melanin - brown to black color of organism

    -Clinical Disease = usually asymptomatic; palmar (palm) and plantar (sole); neck and thorax Females > males, pediatric and adolescents

    -Brown to black nonscaly, macular lesions
  22. Tinea nigra differential diagnosis
    • brown- block flat lesions on palms/feet
    • nevi (mole)
    • Melanoma
    • Contact Dermatitis
    • Melanosis - syphilis, post-inflammatory
    • Form on the feet, just natural
    • Pigmentation - Addisons, pinta
    • Stains - chemicals, dyes, pigments
    • Aureobasidiomycosis
  23. pinta
    Pinta is a human skin disease endemic to Mexico, Central America, and South America. It is caused by infection with a spirochete,
  24. syphilis
    Treponema carateum, which is morphologically and serologically indistinguishable from the organism that causes syphilis.
  25. Everything about tinea versicolor. Everything!
  26. tinea versicolor: etiology
    Malassrezia furfur
  27. tinea versicolor: distribution
    high humidity US, ww ages 15-24
  28. tinea versicolor: clinically
    • scaly macules with HYPOpigmentation and HYPERpigmentation
    • NOT contagious (normal flora)
  29. The most common cause of Madura in the USA
    Pseudallescheria boydii
  30. Actinomyceis is a bacteria
    • Bacteria that act like fungus
    • Gram positive,
    • beaded,
    • filamentous
    • anaerobic
    • Normal flora in mouth and GI
    • Sulfur granules
  31. What is the primary site of infection of nocardia?
    • chest/back?
    • you inhale it
  32. Know if Madura foot is painful or painless
  33. Lumpy jaw. What causes it? 
    Actinomyces israelii 
  34. Aspergillis causes what in the body?
    • a. Asthma (Type I)
    • b. Allergic bronchopulmonary (Types I, III)

    • a. Aspergilloma (Fungus ball) (lungs, paranasal sinuses)
    • b. Otomycosis (external otitis)
    • c. Onychomycosis
    • d. Eye inf. (conjunctival, corneal, intraocular)

    • 1. Pulmonary
    • 2. Disseminated: GI tract, brain, liver, kidney, heart, skin, eye

  35. Know what risk or other medical history is risk for developing zygomycoses?
    • Diabetic ketoacidosis
    • immunosuppression
  36. What makes dermatophytes happy to live/survive?
    • keratinized tissues, epidermis, hair, and nails
    • Most common skin infections seen
    • worldwide
    • The only fungal infections which are contagious
    • Dermatophytes contain keratinase  - digest keratin
  37. Keratinophilic
    =  infect keratinized parts of the body (hair, skin, nails)
  38. Keratinolytic
    break down keratin
  39. Kerion
    extreme inflammatory lesion due to ectothrix infection (hair shaft)