LESSON 4. FUNGI (COMBINED)

Fungi

eukaryotic organisms encompassing both unicellular yeasts and multicellular molds

normal flora

Fungi are widely distributed in nature occurring as part of the _________ on the body of warm-blooded animals, as decomposers of organic matter and as animal and plant pathogens

medically important

Fungi are extreme _____________________ group of microbes being responsible for a number of potentially fatal diseases

great benefit

Fungi are of __________ to humanity in terms of production of alcoholic beverages, bread, enzymes, antibiotics and recombinant proteins

Mycosis

disease caused by infection with a fungus

Malassezia furfur

Examples of Superficial Mycosis:

• cause of Pityriasis versicolor (an-an in Filipino)

Trichosporon beigelii

Examples of Superficial Mycosis:

• cause of White piedra which are granular white substances in our hair shaft near the scalp

Trichophyton rubrum

Examples of Cutaneous Mycosis:

• cause of Tinea pedis (athlete’s foot)

Trichophyton rubrum

Examples of Cutaneous Mycosis:

• cause of Onychomycosis (nail infection)

Trichophyton tonsurans

Examples of Cutaneous Mycosis:

• cause of Tinea capitis

Fonsecaea pedrosoi

Examples of Subcutaneous Mycosis:

• cause of Chromoblastomycosis

Acremonium spp.

Examples of Subcutaneous Mycosis:

• cause of Mycetoma which is characterized by inflammatory response

Blastomyces dermatitidis

Examples of Systemic Mycosis — it is in our blood circulation:

• cause of Blastomycosis

Histoplasma capsulatum

Examples of Systemic Mycosis — it is in our blood circulation:

• cause of Histoplasmosis

Coccidioides immitis

Examples of Systemic Mycosis — it is in our blood circulation:

• cause of Coccidioidomycosis

Paracoccidioides brasiliensis

Examples of Systemic Mycosis — it is in our blood circulation:

• cause of Paracoccidioidomycosis

Candida albicans, Candida glabrata, Candida parapsilosis

Examples of Opportunistic Mycosis

• cause of Candidosis

Aspergillus fumigatus

Examples of Opportunistic Mycosis

• cause of Aspergillosis

Pneumocystis jirovecii (carinii)

Examples of Opportunistic Mycosis

• cause of Pneumonia

Yeasts

• grows as single cells (unicellular) which may reproduce asexually through budding and some through fission, some are capable of sexual reproduction, and formation of spores

Schizosaccharomyces pombe

example of yeasts that reproduce through fission

Molds

• multicellular fungi usually having a branching, filamentous structure

• grow as masses (mycelium) of overlapping and interlinking hyphal filaments and reproduce by producing masses of spores in a variety of structures

Oomycetes

6 CLASSES OF FUNGI:

• mildews and water molds

Ascomycetes

6 CLASSES OF FUNGI:

• mildews, molds, and yeast species

Saccharomyces cerevisiae

example of yeast species under ascomycetes

Basidiomycetes

6 CLASSES OF FUNGI:

• mushrooms and bracket fungi

Teliomycetes

6 CLASSES OF FUNGI:

• rust fungi (plant pathogens)

Ustomycetes

6 CLASSES OF FUNGI:

• smuts (plant pathogens)

Deuteromycetes

6 CLASSES OF FUNGI:

• Aspergillus, Fusarium and Penicillium

• produces antibiotics

Chytridiomycota

4 PHYLA:

• Allomyces (water molds)

Zygomycota

4 PHYLA:

• Rhizopus (bread molds)

• Mucor

Basidiomycota

4 PHYLA:

• mushrooms, rusts, smuts

Ascomycota

4 PHYLA:

• Neurospora (yeast)

• sac fungi

Cell Wall

• rigid

• structural polysaccharides

• contains proteins and lipids in small amounts

glucan

Cell Wall are structural polysaccharides that contains:

a. _____________ - 50-60%

b. _____________ - 15-23%

c. _____________ - 1-9%

a = ?

mannan

Cell Wall are structural polysaccharides that contains:

a. _____________ - 50-60%

b. _____________ - 15-23%

c. _____________ - 1-9%

b = ?

chitin

Cell Wall are structural polysaccharides that contains:

a. _____________ - 50-60%

b. _____________ - 15-23%

c. _____________ - 1-9%

c = ?

Glucan

Parts of the Cell Wall

• main structural component of the fungal cell wall

• branched polymer of glucose which exists in three forms in the cell: β-1,6-glucan, β-1,3- glucan, and β-1,3,- β-1,6-complexed with chitin

Mannan

Parts of the Cell Wall

• a polymer of mannose

• found in the outer layers of the cell wall

• mannoproteins form a fibrillar layer that radiates from an internal skeletal layer

Chitin

Parts of the Cell Wall:

• concentrated in the bud scars that are areas of the cell from which a bud has detached

• innermost layer that also provides rigidity and important in regulating cell division

Protoplast

• naked cell

• devoid of cell wall through enzymatic or mechanical removal

• osmotically fragile (high osmotic pressure)

osmotically stabilized agar growth medium

If protoplast is placed in _____________________________________, cell wall will resynthesize and normal cellular functions will resume

fusing

Importance of Protoplast:

• for RECOMBINATION: generation and _____ of protoplast can generate strains with biotechnological applications

Periplasmic space

• thin region directly below the cell wall

proteins

Periplasmic space contains secreted _________ that do not penetrate the cell wall

processing nutrients

Periplasmic space is the location for a number of enzymes required for _________ prior to entry into the cell

plasmalemma

other term for cell membrane

below the periplasmic space

cell membrane is located _______________________

cell membrane

phospholipid bilayer which contains phospholipids, lipids, protein and sterols

globular

kind of proteins in the cell membrane

ergosterol

dominant sterol in the cell membrane

amphotericin B

Part of the Cell Membrane

• Ergosterol is the target of the antifungal agent ____________

Ergosterol

Part of the Cell Membrane:

• represent regions of rigidity in the fluidity provided by the phospholipid bilayer

Nucleus

discrete organelle that contains the genome

Histones

DNA with proteins

nuclear membrane

Nucleus is surrounded by a ______________________ that contain pores to allow communication with the rest of the cell

chromosomes

vary in size from 0.2 to 6 Mb, and the number per yeast also vary

Plasmids

extrachromosomal genetic material

plasmid in S. cerevisiae

plasmid for faster reproduction

plasmid in Kluyveromyces lactis

killer plasmids that encode a toxin; for fermentation of lactose and dairy products

Mitochondrion

powerhouse of the cell

matrix

In the mitochondria, the enzyme of the TCA cycle (Krebs’ Cycle) are located in the _______________

inner membrane

In the mitochondria, electron transport and oxidative phosphorylation occur in the ___________________

outer membrane

In the mitochondria, enzymes in lipid biosynthesis are on the _______________

own DNA

mitochondria is a semi-independent organelle as it possess its _________

ribosomes (mitoribosomes)

mitochondria is capable of producing its own proteins on its own _______________

protein biosynthesis

ribosomes are attached to your endoplasmic reticulum and is the site of _________

polysomes

lines of ribosomes strung together by a strand of mRNA

Golgi apparatus, endoplasmic reticulum and the plasmalemma

composed the system which mediates the export of proteins from the cell

Vacuole

storage space where nutrients, hydrolytic enzymes or metabolic intermediates are retained

spherical or ovoid

Yeasts are ________________ unicellular bodies typically 2-4 μm in diameter that can reproduce through budding or binary fission

Saccharomyces cerevisiae

baker’s yeast, brewer’s yeast

Cryptococcus neoformans

only significant pathogen which causes the lung infection cryptococcosis

Budding

the offspring emerge as a bud on the side of the parent cell, gradually increases in size and eventually pinches off, forming a daughter cell and leaving an area of scarring

24 offspring

In budding, a single parent can produce up to ________________________

Yeastlike fungi

behave like typical budding yeasts but under certain cultural conditions the buds become elongated to form pseudohyphae which are elongated filaments

Candida albicans

examples of yeastlike fungi

• part of the normal microflora of the body, can cause infections called candidiasis and involve the mouth, vagina, intestinal tract and lungs

Dimorphic fungi

exist as two distinct morphological forms; grow as yeasts or filaments depending on the cultural conditions

filamentous form

CONDITIONS OF DIMORPHIC FUNGI OF HISTOPLASMA CAPSULATUM:

a. below 22 C

b. at 37 C

a = ?

yeast form

CONDITIONS OF DIMORPHIC FUNGI:

a. below 22 C

b. at 37 C

b = ?

Histoplasma capsulatum

example of dimorphic fungi which causes histoplasmosis – can be mild chest infection through to a fatal disease

Filamentous fungi

multicellular molds that grow as slender branching filaments called hyphae, which are typically 2-10 μm in diameter

nonseptate

the hyphae of filamentous fungi can be:

a. coenocytic (no cell walls)

b. with cross walls

a = ?

septate

the hyphae of filamentous fungi can be:

a. coenocytic (no cell walls)

b. with cross walls

b = ?

hyphae

In filamentous fungi, the _________ grows at the hyphal tip into a mycelium

Mucor hiemalis and Rhizopus stolonifer

ex of filamentous fungi that produce nonseptate hyphae

Penicillium and Aspergillus

ex of filamentous fungi that produce hyphae with septa with pores to allow cytoplasm and even nuclei to diffuse along the filament

measuring mass or dry weight

monitoring growth of filamentous fungi is through ___________________________

Candida albicans

• opportunistic fungal pathogen

• present as a normal part of the body’s microflora (mouth, gut and vagina)

antibiotic therapy, diabetes, vitamin deficiency, long-term steroids, immunosuppressive therapy, alcoholism and inappropriate diet

Candida albicans may overgrow due to:

systemic

Candida albicans:

can cause _______ infections that may start as superficial infections

a. _______________ (e.g. esophagus infection rendering difficulty in swallowing) in diabetics, cancer patients and people with AIDS

b. __________________ infection may be due to renal infection or other underlying diseases or cystitis

c. __________________ infection

GIT infection

Candida albicans:

can cause _______ infections that may start as superficial infections

a. _______________ (e.g. esophagus infection rendering difficulty in swallowing) in diabetics, cancer patients and people with AIDS

b. __________________ infection may be due to renal infection or other underlying diseases or cystitis

c. __________________ infection

a = ?

urinary tract

Candida albicans:

can cause _______ infections that may start as superficial infections

a. _______________ (e.g. esophagus infection rendering difficulty in swallowing) in diabetics, cancer patients and people with AIDS

b. __________________ infection may be due to renal infection or other underlying diseases or cystitis

c. __________________ infection

b = ?

indwelling urinary catheter

Candida albicans:

can cause _______ infections that may start as superficial infections

a. _______________ (e.g. esophagus infection rendering difficulty in swallowing) in diabetics, cancer patients and people with AIDS

b. __________________ infection may be due to renal infection or other underlying diseases or cystitis

c. __________________ infection

c = ?

local

Candida albicans:

can also cause _____ infections

a. _____________________________________– infection in the mouth and vagina

b. ________________________ – infection of the skin

c. ________________________ – infection of the bronchi and lungs

candidiasis of the mucous membranes (thrush)

Candida albicans:

can also cause _____ infections

a. _____________________________________– infection in the mouth and vagina

b. ________________________ – infection of the skin

c. ________________________– infection of the bronchi and lungs

a = ?

cutaneous candidiasis

Candida albicans:

can also cause _____ infections

a. _____________________________________– infection in the mouth and vagina

b. ________________________ – infection of the skin

c. ________________________– infection of the bronchi and lungs

b = ?

bronchopulmonary candidiasis

Candida albicans:

can also cause _____ infections

a. _____________________________________– infection in the mouth and vagina

b. ________________________ – infection of the skin

c. ________________________– infection of the bronchi and lungs

c = ?

mouthwash

When a patient is prescribed with antibiotics or strong steroids, ______________ are also prescribed so that the fungal infections would not thrive.

immune system

Risk factors for infection of Candida albicans:

1. impaired _______________

a. ______________________ (AIDS, cancer, diabetes)

b. use of __________________ during organ transplantation and broad-spectrum antibiotic therapy

2. presence of ________________________

3. __________ as result of burns or other trauma

1 = ?