1. Mycology
Disease of Yeast & Mold

2. Mycology Study of fungi includes yeast and mold Eukaryotic cell
Chemo-heterotroph - require organic compounds for energy and carbon source
Most have cell wall of chitin

3. Mold Septate hyphae - cross wall divide hyphae into uninucleate unit
Hyphae - long filament
Septate hyphae - cross wall divide hyphae into uninucleate unit
Non-septate (coenocytic) hyphae - no cross wall
Mycelium – hyphae grow, intertwine

4. Yeast Non-filamentous, unicellular fungi Oval or spherical in shape
Reproduce by budding
Pseudohyphae - buds fail to detach; i.e. germ tube test for Candidia

5. Dimorphic Fungi
Dimorphism – two forms of growth, either yeast or mold; most pathogens
Temperature dependent:
37°C grows as yeast
RT grows as mold
CO2 concentration or presence of serum may also be a determining factor
Dimorphism of Candida different:
37°C grows as mold in serum (Germ tube test)
RT grows as yeast

6. Lab ID Type of hyphae: septate, non-septate Color of mycelium
Reproductive structures:
Sexual spores - fusion of nuclei from two opposite mating strains of same species; only under special conditions
Asexual spores - commonly used in ID; aerial mycelium by mitosis and cell division
Results in conidia

7. Arthrospores Arthron = “joint”, arthroconidia
Fragmentation of septate hyphae
i.e. Coccidiodes

8. Chlamydospores Chlamy = “mantle”
Thick walled spores formed within a hyphae
i.e. Candida

9. Sporangiospores Angeion = “vessel”
Sporangium - Spores formed within a sac
i.e. Rhizopus

10. Condiospores Conidia = “dust’
Conidiophore –aerial mycelium; spores produced at end
Macroconidia -multicelled conidiospores
i.e. Histoplasma

11. Blastospores Blastos = “bud” “shoot”, Blastoconidia
Bud coming off parental cell
i.e. Blastomyces

12. Fungal Diseases Mycosis - fungal infection
Mode of entry & infective tissue:
Superficial
Cutaneous
Subcutaneous
Systemic
Opportunistic

13. Superficial Mycoses Localized hair shaft, surface epidermis
Direct contact with infected hair, skin
White piedra - white balls found on hair shafts;Trichosporon
Black piedra - infecting hair, producing hard, dark nodules; Piedraia

14. Cutaneous Mycoses “Ringworm” – hair, epidermis, nail
Epidermophyton, Microsporum, Trichophyton
Dermatophytes - secrete keratinase
Person to person, animal to person
Direct contact infected hair, skin
Tinea capitis (scalp, hair), Tinea pedis (athlete’s foot), Tinea unguium (nails)

15. Subcutaneous Mycoses Mycetoma - beneath skin
Fonsecaea, Phialophora, Pseudoallescheria
Fungi that live in soil and vegetation
Spores or hyphae planted directly into puncture wound
Infection not contagious

16. Systemic Mycosis Deep, involve tissues and organs
Saprophytic fungi, live in soil
Inhalation of spores - in lung, spreads other tissues
Often resemble tuberculosis
Not contagious
Blastomycosis - Blastomyces, flu-like, pulmonary
Coccidioidomycosis - Coccidiodes, San Joaquin Valley Fever
Histoplasmosis - Histoplasma, pulmonary

17. Opportunistic Mycoses
Harmless in normal habitat (includes normal flora), pathogenic in debilitated host
Mucormycosis – Mucor; diabetic patient with ketoacidosis
Aspergillosis – Aspergillus; inhale spores, neutropenic patient (lung disease, cancer)
Candidiasis – Candida
Vulvovaginal following antibiotic therapy
Thrush of mouth and throat

18. MICR 301 Final Exam (200 pts.) Tuesday, Dec. 6, 2011 8:00 – 10:30am
Lecture, Reading, Key Terms, Learning Assessment Questions, Five Case Study
Virus, Bacteria, Fungi, Parasite Lectures
Part I (~65%): Mechanism of Pathogenesis thru Parasites
Part II (~35%): Introduction thru Specific Host Defense
Objective (M.C., Terms, T/F), Short Essay