FUNGAL SPORES Dr Hams Mohamed Ahmed Assistant professor

FUNGAL SPORES Dr/ Hams Mohamed Ahmed Assistant professor of Microbiology

Reproduction

FUNGAL SPORES Function in reproduction of fungi 1. Sexual reproduction -- Sexual spores 2. Asexual reproduction -- Asexual spores a. Sporulation b. Fragmentation c. Budding 3. Parasexual reproduction -- Genetic exchange

ASEXUAL SPORES 1 -conidia 2. Arthrospore 3. Blastospore 4. Chlamydospore

Blastospore

Aspergillus Species

Rhizopus: sporangium filled with sporangiospores.

SEXUAL SPORES 1. Zygospore 2. Ascospore 3. Basidiospore 4. Oospore

SEXUAL SPORE CLASS Zygospore----- Zygomycetes Basidiospore---- Basidiomycetes Ascospore----- Ascomycetes None/Unknown------ Deuteromycetes (“Fungi imperfecti”)

• Zygospore-----1 -Migration of nuclei will occur in the tips of both progametangia 2 -Septa are laid down at the apex of the progametangia to form isogametangia Zygomycet

3 -Karyogamyimmediately follows to form a multinucleate zygote 4 -The zygote will form a thick, pitted wall around itself to form the zygospore

�Basidiospore---- Basidiomycetes

Ascospore----- Ascomycetes

Stages of ascus formation Ascus mother cell crozie r

PATHOGENICITY OF FUNGI 1. Thermotolerance 2. Ability to survive in tissue environment 3. Ability to withstand host defenses

Features of Fungus Infections o Not contagious; dermatophytes exception o Opportunistic o Host is predisposed and/or exposed to large number of spores o Infections are chronic with granulomatous lesions

o Cell-mediated immunity - important o Hypersensitivity response may develop o Infections are asymptomatic or selflimited

Fungal Infections Clinical Classification Superficial mycoses Subcutaneous/intermediate mycoses Systemic/deep/endemic mycoses Miscellaneous mycoses/yeasts /Opportunistic

Superficial Mycoses Chest, back, upper arm Rarely invade deeper tissue Malssezia

Cutaneous mycosis Skin, hair and nails • Dermatophytes (Microsporum, tricophyton, epidermiphyton)

Subcutaneous Mycoses Madurella v. Confined to subcutaneous tissue and rarely spread systemically. v. The causative agents are soil organisms introduced into the extremities by trauma.

Systemic Mycoses § Caused by: dimorphic fungi § histoplasma, blastomyces, coccidioides, sporothrix § Involve skin and deep viscera § May become widely disseminated § Predilection for specific organs

OPPORTUNISTIC FUNGI saprophytes and occasional pathogens that invade the tissues of those who have: • Predisposing diseases: Diabetes, cancer, leukemia, etc. • Predisposing conditions: Agammaglobulinemia, steroid or antibiotic therapy.

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