Babylone University Dentist College

1. Oral MycologyOral Mycology
lectuerlectuer (19)(19)
Dr.Baha,Hamdi.ALDr.Baha,Hamdi.AL--AmiedieAmiedie
Ph.D.MicrobiologyPh.D.Microbiology

2. Characteristic of fungiCharacteristic of fungi
11--•• EukaryotesEukaryotes
22-- NoNo chlorophylchlorophyl (distinguishes them from(distinguishes them from
plants and algae)plants and algae)
33-- Unicellular to filamentousUnicellular to filamentous
44-- Rigid cell wallRigid cell wall
55--Spore bearing stages in the life cycleSpore bearing stages in the life cycle
66--Usually reproduce by sexual and asexualUsually reproduce by sexual and asexual
meansmeans
77--Insensitive to antibacterial antibioticsInsensitive to antibacterial antibiotics

3. ComparisingComparising between fungi &Bacteriabetween fungi &Bacteria

4. Cell wall structure of fungiCell wall structure of fungi

5. Morphological types of fungiMorphological types of fungi
Three major groupsThree major groups
1. Moulds1. Moulds
2. Yeasts2. Yeasts
3. Mushrooms3. Mushrooms
Dimorphic fungiDimorphic fungi –– fungifungi that havethat have
both aboth a
yeast stage and a mould stageyeast stage and a mould stage

6. In many cases vegetative cell ofIn many cases vegetative cell of hyphahypha
contains morecontains more
than one nucleusthan one nucleus –– typicaltypical hyphahypha is ais a
nucleated tubenucleated tube
containing a cytoplasm ( acontaining a cytoplasm ( a coenocyticcoenocytic))
and no septaand no septa
(cross walls)(cross walls)
•• SeptateSeptate hyphaehyphae have one or two nucleihave one or two nuclei
per cellper cell

8. Asexual sporesAsexual spores
Asexual reproductionAsexual reproduction
Asexual spore formation:Asexual spore formation:
•• chlamydosporeschlamydospores (formed within(formed within
sporangia)sporangia)
•• conidia (formed naked at tips ofconidia (formed naked at tips of
hyphaehyphae))
•• budding (cell division)budding (cell division)
•• fragmentation (of mycelium)fragmentation (of mycelium)

9. Asexual sporesAsexual spores

10. Sexual sporesSexual spores
Sexual spores areSexual spores are
resistant to dryingresistant to drying
heating, freezing, andheating, freezing, and
some chemical agentssome chemical agents
•• Not as resistant to heatNot as resistant to heat
as are bacterialas are bacterial
endosporesendospores
•• Either a sexual spore orEither a sexual spore or
an asexual spore canan asexual spore can
germinate and developgerminate and develop
into a newinto a new hyphahypha and Myceliumand Mycelium

11. Sexual sporeSexual spore

12. Fungal infection typesFungal infection types
11--Rang fromRang from superficalsuperfical infection toinfection to
ovewhelmingovewhelming systemic infections thatsystemic infections that
are rapidly fatal in the compromisedare rapidly fatal in the compromised
hosthost
22--they are increased in frequency asthey are increased in frequency as
result of increased used of antibioticsresult of increased used of antibiotics
CorticostroidsCorticostroids&& cytotoxiccytotoxic drugsdrugs
33--classified intoclassified into superficalsuperfical,, cutaneouscutaneous
Subcutaneous&systemicSubcutaneous&systemic
infection;Systemicinfection;Systemic infection areinfection are
subdiviedsubdivied into those caused byinto those caused by
opportunistic fungi & by thoseopportunistic fungi & by those
caused by pathogenic fungicaused by pathogenic fungi

13. Oral Aspect of fungal infectionsOral Aspect of fungal infections
Fungal infections in the oral andFungal infections in the oral and
perioralperioral regions occur either asregions occur either as
primary localized lesions or asprimary localized lesions or as
manifestations of systemic mycosesmanifestations of systemic mycoses..
By far the most common group ofBy far the most common group of
fungal infections that dentalfungal infections that dental
practitioners diagnose and treat arepractitioners diagnose and treat are
caused by Candidacaused by Candida sppspp.. Some of theSome of the
rarer mycoses with oralrarer mycoses with oral
manifestationsmanifestations