Oral Mycology
lectuer (19)
Dr.Baha,Hamdi.AL-Amiedie
Ph.D.Microbiology
Characteristic of fungi
1-• Eukaryotes 
2- No chlorophyl (distinguishes them from
plants and algae) 
3- Unicellular to filamentous 
4- Rigid cell wall 
5-Spore bearing stages in the life cycle 
6-Usually reproduce by sexual and asexual
means 
7-Insensitive to antibacterial antibiotics 


Comparising between fungi &Bacteria
Cell wall structure of fungi
Morphological types of fungi
Three major groups 
1. Moulds 
2. Yeasts 
3. Mushrooms 

Dimorphic fungi – fungi that have
both a
yeast stage and a mould stage 

In many cases vegetative cell of hypha
contains more
than one nucleus – typical hypha is a 
nucleated tube

containing a cytoplasm ( a coenocytic) 
and no septa
(cross walls) 
• Septate hyphae have one or two nuclei
per cell

Asexual spores
Asexual reproduction 
Asexual spore formation: 
• chlamydospores (formed within 
sporangia) 
• conidia (formed naked at tips of 
hyphae) 
• budding (cell division) 
• fragmentation (of mycelium)

Asexual spores
Sexual spores
Sexual spores are 
resistant to drying 
heating, freezing, and 
some chemical agents 
• Not as resistant to heat 
as are bacterial 
endospores 
• Either a sexual spore or 
an asexual spore can 
germinate and develop 
into a new hypha and Mycelium

Sexual spore
Fungal infection types
1-Rang from superfical infection to 
ovewhelming systemic infections that
are rapidly fatal in the compromised
host
2-they are increased in frequency as 
result of increased used of antibiotics
Corticostroids& cytotoxic drugs 
3-classified into superfical, cutaneous 
Subcutaneous&systemic 
infection;Systemic infection are
subdivied into those caused by
opportunistic fungi & by those
caused by pathogenic fungi
Oral Aspect of fungal infections
Fungal infections in the oral and 
perioral regions occur either as
primary localized lesions or as
manifestations of systemic mycoses.
By far the most common group of
fungal infections that dental
practitioners diagnose and treat are
caused by Candida spp. Some of the
rarer mycoses with oral
manifestations