Introduction to Mycology
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AN INTRODUCTION TO MEDICAL MYCOLOGY
David H. Ellis, Mycology Unit, Women 's and Children 's Hospital, Adelaide.
Definition of fungi.
The living world is divided into the five kingdoms of Planta, Animalia, Fungi, Protista and Monera. It is important to recognize that the fungi are not related to bacteria (Monera). To define the exact limits of the groups in a few words is virtually impossible, however generally speaking fungi are eukaryotica, heterotrophicb, unicellular to filamentous, rigid cell walledc, sporebearing organisms that usually reproduce by both sexual and asexual means. Further they are insensitive to antibacterial antibiotics. a Eukaryotic cells contain membrane bound cell organelles including nuclei, mitochondria, golgi apparatus, endoplasmic reticulum, lysosomes etc. Eukaryotes also exhibit mitosis. These features separate fungi from bacterial which are prokaryotic cells lacking the above structures. Heterotrophic - fungi lack chlorophyll and are therefore not autotrophic (photosynthetic) like plants and algae; rather they are heterotrophic absorptive organisms that are either saprophytes (living on dead organic matter) or parasites (utilizing living tissue). Like plants, fungi have rigid cell walls and are therefore non-motile, a feature which separates them from animals.
b
c
Structure of Fungi.
Fungi occur in two basic growth forms or stages: (a) A unicellular or yeast form which is defined morphologically, as a single-celled fungus that reproduces by simple budding to form blastoconidia. Colonies are usually moist or mucoid. Yeast-like fungi may be basidiomycetes, such as Cryptococcus neoformans or ascomycetes such as Candida albicans. A filamentous or mould form which is a vegetative growth of filaments. Structures such as mushrooms consist simply of a number of filaments packed tightly together, and reproduction is by spores or conidia. Moulds produce a great variety of conidia which are borne on specialized hyphae or
AN INTRODUCTION TO MEDICAL MYCOLOGY
David H. Ellis, Mycology Unit, Women 's and Children 's Hospital, Adelaide.
Definition of fungi.
The living world is divided into the five kingdoms of Planta, Animalia, Fungi, Protista and Monera. It is important to recognize that the fungi are not related to bacteria (Monera). To define the exact limits of the groups in a few words is virtually impossible, however generally speaking fungi are eukaryotica, heterotrophicb, unicellular to filamentous, rigid cell walledc, sporebearing organisms that usually reproduce by both sexual and asexual means. Further they are insensitive to antibacterial antibiotics. a Eukaryotic cells contain membrane bound cell organelles including nuclei, mitochondria, golgi apparatus, endoplasmic reticulum, lysosomes etc. Eukaryotes also exhibit mitosis. These features separate fungi from bacterial which are prokaryotic cells lacking the above structures. Heterotrophic - fungi lack chlorophyll and are therefore not autotrophic (photosynthetic) like plants and algae; rather they are heterotrophic absorptive organisms that are either saprophytes (living on dead organic matter) or parasites (utilizing living tissue). Like plants, fungi have rigid cell walls and are therefore non-motile, a feature which separates them from animals.
b
c
Structure of Fungi.
Fungi occur in two basic growth forms or stages: (a) A unicellular or yeast form which is defined morphologically, as a single-celled fungus that reproduces by simple budding to form blastoconidia. Colonies are usually moist or mucoid. Yeast-like fungi may be basidiomycetes, such as Cryptococcus neoformans or ascomycetes such as Candida albicans. A filamentous or mould form which is a vegetative growth of filaments. Structures such as mushrooms consist simply of a number of filaments packed tightly together, and reproduction is by spores or conidia. Moulds produce a great variety of conidia which are borne on specialized hyphae or
References: Rippon, J.W. 1988. Medical Mycology (3rd. edition). W.B. Saunders Co. Kwon-Chung, K.J. and J.E. Bennett. 1992. Medical Mycology. Lea & Febiger.