1. Classification of fungi
Mrs. Dalia Kamal Eldien
Msc in Microbiology
Lecture NO (2)

2. Objectives
Classification of fungi according to method of reproduction & type of hyphae
Identification of the different classes of fungi
Zygomycetes (phycomycetes)
Ascomycetes
Basidiomycetes
Deuteromycetes

3. Classification of fungi
There are many ways for fungi classification, but the most practical approaches based on:
Method of reproduction
Type of hyphae
Basing on those criteria they classify the fungi in to four groups
Zygomycetes (phycomycetes)
Ascomycetes
Basidiomycetes
Deuteromycetes (Fungi imperfecti)

4. Zygomycetes (phycomycetes)

5. Scientific classification
Kingdom: Fungi
Phylum: Zygomycota
Class: Zygomycetes

6. Zygomycetes (phycomycetes)
Commonly known as bread moulds
Zygomycetes are fast growing
Hyphae are aseptate
Reproduce sexual and asexual .
Asexual reproduction produce the sporangiospores, found within sac like structure known as sporangia, sporangia are borne on special hyphae called sporangiophore.
This endogenous process of spore formation within a sac is known as Sporogenesis.

8. Zygomycetes under light microscope

9. Identify the different parts?

10. Zygomycetes (phycomycetes)
Sexual reproduction involves producing a thick-walled spore called a zygospore.
Example: Rhizopus, Mucor, Rhizomucor

11. ASCOMYCETES

12. Scientific classification
Kingdom: Fungi
Subkingdom:Dikarya
Phylum: Ascomycota
Class : Ascomycetes

13. Ascomycetes
The Hyphae of ascomycetes are septate with simple septal pores
Reproduce sexual and asexual .
Asexual reproduction produce the conidia.
Conidia arise by budding of conidiogenous hyphae
Conidia are borne on specialized structures called conidiophore (hyphae that bear conidia)

14. Asexual reproduction of ascomycetes

15. Conidia of ascomycetes

16. Sexual reproduction is by the formation of endogenous ascospores, are the largest sexual spore usually are eight in number, present in an ascus sac, group of asci found in ascocarp.

17. Sexual reproduction of ascomycetes
2-The female portion usually enlarges and gametangia fuse.  The fusion cell enlarges into a sac
1-Two gametangia arise on adjacent cells and nuclei migrate
 3-Meiosis takes place to produce many nuclei

18. Fungus with Ascospores (8 in number)

19. BASIDIOMYCETES

20. Scientific classification
Kingdom: Fungi
Subkingdom:Dikarya
Phylum: Basidiomycota
Class: Basidomycetes

21. Basidomycetes Less medically important group
Have septated hyphe and reproduce sexually only
The sexual spore known as basidospore found in the tip of hyphe typically, four on a basidium
Example: Mushrooms

22. Sexual reproduction of basidomycetes

23. DEUTEROMYCETES

24. Deuteromycetes Also name as Fungi imperfecti or imperfect fungi
Are the most medically important group
Have septated hyphe
Reproduce sexually and asexually, but mostly asexually, result in formation of 3 types of spore:-
Thallospore
Conidiospore
Sporingiospore

25. Thallospore:-
are formed with in the hyphe, are two types
Arthrospore: by fragmentation of the terminal part of hyphe, seen in pathological specimen not culture
b) Chlamydospore: formed by migration of content of two adjacent cells

26. Arthrospore

27. Chlamydospore

28. Conidiophore Conidia are asexual spore, important in identification of some fungi, have different shape, size & arrangement:
Macroconidia: large& multicellular
Microconidia: small& unicellular
Sporingiospore
Similar to zygomcytes but the hypha is septated

29. Pathogenesis of fungi
Most fungi are saprophytic or parasitic to plants and are adapted to their natural environment.
Infection in humans is a chance event, occurring only when conditions are favorable.
Except for few fungi such as the Dimorphic fungi that cause systemic mycoses and Dermatophytes, which are primary pathogens, the rest are only opportunistic pathogens.

30. Fungal Diseases (Mycoses)
Mycosis is the infection cause by fungi, classify according to the tissue levels of infection to: 1. Superficial mycoses are limited to the outermost layers of the skin I. Superficial phaeohyphomycosis II. Tinea versicolor III. Black piedra IV. White piedra 2- Cutaneous mycoses extend deeper into the epidermis, and also include invasive hair and nail disease I. Dermatophytosis

31. 3- Subcutaneous mycoses involve the dermis, subcutaneous tissues, muscle and fascia. I. Chromoblastomycosis II. Rhinosporidiasis III. Mycetoma 4- Systemic (deep) mycoses due to primary pathogens originate primarily in the lungs and may spread to many organ systems, In general primary pathogens that cause systemic mycoses are dimorphic. I. Blastomycosis II. Histoplasmosis

32. I. Candidiasis II. Aspergillosis
5- Opportunistic mycoses Systemic mycoses due to opportunistic pathogens are infections of patients with immune deficiencies
I. Candidiasis
II. Aspergillosis

33. Factors predispose fungal infection
Prolonged antibiotic therapy
Underlying disease (HIV infection, cancer, diabetes, etc.)
Age
Surgical procedures
Immunosuppressive drugs
Irradiation therapy
Indwelling catheters
Obesity
Drug addiction
Organ transplants