1. Chapter 7 Fungal Classification, Structure, and Replication
Medical Microbiology
Chapter 7
Fungal Classification, Structure, and Replication

2. Importance of Fungi Fungi are ubiquitous and diverse
They have recently emerged as significant pathogens
Especially among immunocompromised and hospitalized individuals
Table 7-1
According to your book, “there are no nonpathogenic fungi!”

3. Fungi Fungi are eukaryotic cells
Problem with treatment?
They contain a rigid cell wall made of chitin and glucan
They also have ergosterol in their membranes
Figure 7-1

4. Fungi Morphologies: Yeasts – single-celled organisms
Replication by budding or fission
May produce pseudohyphae
Produce colonies on agar
Molds – multicellular organisms
Consist of hyphae that form a mat-like structure called a mycelium
Dimorphic Fungi – can be found as either yeasts or molds
Figures 7-2 and 7-3

5. Human Mycoses Mycosis – infection caused by a fungus
Superficial mycoses – limited to very superficial surfaces of skin and hair
Of cosmetic importance only
Figures 72-3 and 72-5
Cutaneous mycoses – infections of the skin, hair, and nails
Signs and symptoms – itching, scaling, broken hairs, ring-like patch on the skin, thickened, discolored nails.
Caused by “dermatophytes”
Figures 72-14, 72-15, and 72-16

6. Human Mycoses Subcutaneous mycoses – infections of the deeper tissues
Can cause abscesses and non-healing ulcers
Figures 73-1, 73-5, 73-8, and 73-9
Endemic Mycoses – systemic infections
Fungi exhibit thermal dimorphism
Can infect healthy individuals
Generally confined to specific areas
Figures 74-2, 74-5, 74-6, 74-12, and 74-14

7. Human Mycoses Opportunistic Mycoses – normally non-pathogenic fungi
Candida spp. – thrush, vaginal yeast infections, other more serious infections
Cryptococcus neoformans – pulmonary and CNS infections
Figure 75-10
Aspergillus spp.
others

8. Disease of the Day
“The Terminator” article

9. Summary
Summary – page 73