Biomedical Engineering Reference
In-Depth Information
Chapter 33
Overview of Class Fungi
Definition of a lexicographer: “harmless drudge.”
Samuel Johnson
Eukaryota
Bikonta, 2-flagella (Chapter 16
21)
Unikonta, 1-flagellum
Amoebozoa (Chapter 22)
Opisthokonta
Choanozoa (Chapter 23)
Animalia (Chapters 25
32)
Fungi
Zygomycota (Chapter 34)
Dikarya
Basidiomycota (Chapter 35)
Ascomycota (Chapter 36)
Microsporidia (Chapter 37)
In the past decade, Class Fungi has become the most intellectually frustrating
branch of clinical microbiology. There are many reasons why mycology (the
study of fungi) has become so very difficult.
1.
Number of offending organisms. Approximately 54 fungi account for the
vast majority of fungal infections, the actual number of fungi that are
pathogenic in humans is much higher. To provide some idea of the ubi-
quitous nature of fungi, it is estimated that, on average, humans inhale
about 40 conidia (spores from Class Ascomycota) each hour. Most of
these organisms are non-pathogenic under normal circumstances.
However, in the case of immune-compromised patients, or in the case of
patients who provide a specific opportunity for ambient fungi to attach
and grow within a body (e.g. an indwelling vascular line), an otherwise
harmless fungus may produce a life-threatening illness. As the number of
immune-compromised patients increases, due to transplants, AIDS, cancer
treatment, long-term steroid use; and with the proliferation of medical
