Ch 5 Euk Microbes

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The EukaryotesThe EukaryotesWhat makes a eukaryote?What makes a eukaryote?

Why are theseWhy are theseinfestations/infections important?infestations/infections important?



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FungiFungi

Algae Algae

ProtozoaProtozoaHelminthsHelminths

Arthropods Arthropods



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FungiFungi

Mycology is the study of fungi.Mycology is the study of fungi.

Fungal infections are increasingFungal infections are increasing

Are aerobic or facultatively anaerobic Are aerobic or facultatively anaerobicChemoheterotrophs.Chemoheterotrophs.

Decomposers that are parasites of plants.Decomposers that are parasites of plants.



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Fungi CharacteristicsFungi Characteristics

Thallus consists of filaments called hyphae, aThallus consists of filaments called hyphae, amass of hyphae is mycelium.mass of hyphae is mycelium.

Yeasts are unicellular fungi.Yeasts are unicellular fungi.

Some yeast can change morphology are moldSome yeast can change morphology are moldlike at 25¶Clike at 25¶C

Classified according to the sexual structure thatClassified according to the sexual structure thatis formed.is formed.

Grow in acidic, low moisture aerobicGrow in acidic, low moisture aerobicenvironments.environments.

Can metabolize complex carbs.Can metabolize complex carbs.



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YeastsYeastsUnicellular fungiUnicellular fungi Fission yeasts divide symmetricallyFission yeasts divide symmetrically

Budding yeasts divide asymmetricallyBudding yeasts divide asymmetrically

Figure 12.3



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DimorphismDimorphism PathogenicPathogenic

dimorphicdimorphic

fungi arefungi are

yeastlike atyeastlike at

3737°°C andC andmoldlike atmoldlike at

2525°°CC

Figure 12.4



7Figure 12.2

MoldsMolds

The fungalThe fungal thallusthallus consists of consists of hyphaehyphae; a; a

mass of hyphae is amass of hyphae is a myceliummycelium..



8Figure 12.1

Vegetative GrowthVegetative Growth



9Figure 12.5a

Asexual Reproduction Asexual Reproduction

Conidia or conidiosporesConidia or conidiospores



10Figure 12.5b


Arthroconidia Arthroconidia



11Figure 12.5c


BlastoconidiaBlastoconidia



12Figure 12.5d


ChlamydoconidiaChlamydoconidia



13Figure 12.5e


SporangiosporesSporangiospores



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Sexual ReproductionSexual Reproduction

Three phases:Three phases:

PlasmogamyPlasmogamy: Haploid donor cell nucleus (+): Haploid donor cell nucleus (+)

penetrates cytoplasm of recipient cell (penetrates cytoplasm of recipient cell (± ±))

KaryogamyKaryogamy: + and: + and ± ± nuclei fusenuclei fuse

MeiosisMeiosis: Diploid nucleus produces haploid: Diploid nucleus produces haploid

nuclei (sexual spores)nuclei (sexual spores)



15Figure 12.6

Sexual SporesSexual Spores

ZygosporeZygospore: Fusion of haploid cells: Fusion of haploid cells

produces one zygosporeproduces one zygospore



16Figure 12.7


AscosporeAscospore: Formed in a sac (ascus).: Formed in a sac (ascus).



17Figure 12.8


BasidiosporeBasidiospore: Formed externally on a: Formed externally on a

pedestal (basidium)pedestal (basidium)



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Some Fungal DiseasesSome Fungal Diseases

Systemic mycoses are infections withinSystemic mycoses are infections within

the body may affect many organ systems.the body may affect many organ systems.

Subcutaneous under skin.Subcutaneous under skin.Cutaenous is in skin nails and hair ect.Cutaenous is in skin nails and hair ect.

Superficial mycoses on only exterior parts.Superficial mycoses on only exterior parts.

Opportunistic: aspergillosis caused byOpportunistic: aspergillosis caused by Aspergillus Aspergillus, Candidiasis, Candidiasis CandidaCandida



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Economic Effects of Fungi.Economic Effects of Fungi.

Many are used for production of food andMany are used for production of food and

beverages.beverages.

Biological control of pests.Biological control of pests.Mold spoilage of fruits grains andMold spoilage of fruits grains and

vegetables.vegetables.

Diseases in plants.Diseases in plants. Infections in fuel lines fungal mats.Infections in fuel lines fungal mats.

Degradation of cellulose materials.Degradation of cellulose materials.



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Treatments of Fungal InfectionsTreatments of Fungal Infections

Amphotericin B destroys membrane used Amphotericin B destroys membrane used

on Systemic fungal infections.on Systemic fungal infections.

Griseofulvin (inhibit mitotic microtubules)Griseofulvin (inhibit mitotic microtubules)on many skin fungi.on many skin fungi.

Tolnaftate (Athletes foot)Tolnaftate (Athletes foot)

Can you think of any others?Can you think of any others?



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LichensLichens

Mutualistic combination of alga andMutualistic combination of alga and

fungus.fungus.

One is photosynthetic, on is the holdfastOne is photosynthetic, on is the holdfastabsorber.absorber.

Colonize habitats that are unsuitable for Colonize habitats that are unsuitable for

either the alga or the fungus alone.either the alga or the fungus alone.

Used for pigments and air qualityUsed for pigments and air quality

indicators.indicators.



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Algae Algae

Unicellular filamentous are Multicellular.Unicellular filamentous are Multicellular.

Most algae live in aquatic environments.Most algae live in aquatic environments.



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CharacteristicsCharacteristics

Eukaryotic photoautotrophs.Eukaryotic photoautotrophs.

Thallus or body is stipe, holdfast andThallus or body is stipe, holdfast and

blades.blades.Reproduce sexually and asexually byReproduce sexually and asexually by

fragmentation.fragmentation.

Most reproduce sexually.

Most reproduce sexually.

Photoautrophs that produce oxygen.Photoautrophs that produce oxygen.

Classified by structure and pigments.Classified by structure and pigments.



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Characterized by color Characterized by color

Brown algae (kelp)Brown algae (kelp)

Red algae grow at deeper levels.Red algae grow at deeper levels.

Green algae similar to plants.Green algae similar to plants.Diatoms unicellular produce neurotoxins.Diatoms unicellular produce neurotoxins.

Dinoflagellates also cause neurotoxins.Dinoflagellates also cause neurotoxins.



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Role in NatureRole in Nature

Primary producers in aquatic food chains.Primary producers in aquatic food chains.

Produce most of molecular oxygenProduce most of molecular oxygen

Much of our petroleum is fossil remains of Much of our petroleum is fossil remains of plankton.plankton.

Many unicellular algae are symbionts inMany unicellular algae are symbionts in

animals.animals.



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ProtozoaProtozoa

Are unicellular eukaryotic Are unicellular eukaryotic

Chemoheterotrophs.Chemoheterotrophs.

Found in soil, water and as normalF

ound in soil, water and as normalmicrobiotamicrobiota



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Some that cause disease.Some that cause disease.

Archaezoa lack mitochondria and have Archaezoa lack mitochondria and have

flagella.flagella. T richomonasT richomonas andand GiardiaGiardia

Microsporidia lack mitochondria and

Microsporidia lack mitochondria andmicrotubules cause diarrhea in AIDSmicrotubules cause diarrhea in AIDS

patientspatients

Rhizopodia are amoeba, includeRhizopodia are amoeba, include

E ntamoebaE ntamoeba andand Acanthamoeba Acanthamoeba



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More DiseaseMore Disease

Apicomplexa can penetrate host tissue Apicomplexa can penetrate host tissue

includeinclude P lasmodiumP lasmodium andand CryptosporidiumCryptosporidium

Ciliophora move by means of ciliaCiliophora move by means of ciliaBalantidium coli Balantidium coli is a human parasiticis a human parasitic

ciliateciliate

Euglenozoa move by means of flagellaEuglenozoa move by means of flagella

and lack sexual reproduction includeand lack sexual reproduction include

T rypanosomaT rypanosoma



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ProtozoaProtozoa

Kingdom Protist

Nutritional Type Chemoheterotroph

Multicellularity None

Cellular Arrangement Unicellular

Food Acquisition

Method

Absorptive; ingestive

Characteristic

Features

Motility; some form

cysts

Embryo Formation None



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Characteristics of ProtozoaCharacteristics of Protozoa

Vegetative form is aVegetative form is a trophozoitetrophozoite

Asexual reproduction is by fission, Asexual reproduction is by fission,

budding, or budding, or schizogonyschizogony Sexual reproduction bySexual reproduction by conjugationconjugation

Some produceSome produce cystscysts



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Medically Important Phyla of Medically Important Phyla of

ProtozoaProtozoa Archaezoa Archaezoa

MicrosporaMicrospora

Amoebozoa Amoebozoa Apicomplexa Apicomplexa

CiliophoraCiliophora

EuglenozoaEuglenozoa



38Figure 12.16b

Archaezoa Archaezoa

No mitochondriaNo mitochondria

Multiple flagellaMultiple flagella

Giardia lambliaGiardia lamblia T richomonasT richomonas

vaginalisvaginalis (no(no

cyst stage)cyst stage)



39Figure 12.16c, d

Archaezoa Archaezoa



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MicrosporaMicrospora

No mitochondriaNo mitochondria

NonmotileNonmotile

Intracellular parasitesIntracellular parasitesN osemaN osema



41Figure 12.17a

Amoebozoa Amoebozoa

Move byMove by

pseudopodspseudopods

E ntamoeba

E ntamoeba

Acanthamoeba Acanthamoeba



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Apicomplexa Apicomplexa

NonmotileNonmotile

Intracellular parasitesIntracellular parasites

Complex life cyclesComplex life cycles P lasmodiumP lasmodium

BabesiaBabesia

CryptosporidiumCryptosporidiumCyclosporaCyclospora



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3

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Figure 12.18

The Life Cycle of The Life Cycle of P lasmodiumP lasmodium

vivax vivax



44Clinical Focus, p. 355

CryptosporidiumCryptosporidium



45Clinical Focus, p. 355

CryptosporidiumCryptosporidium



46Figure 12.19

CiliatesCiliates

Move by ciliaMove by cilia

ComplexComplex

cellscells BalantidiumBalantidium

coli coli is theis the

only humanonly human

parasiteparasite



47Figure 12.20


Move by flagellaMove by flagella

EuglenoidsEuglenoids

PhotoautotrophsPhotoautotrophs



48Figure 23.22


Move by flagellaMove by flagellaHemoflagellatesHemoflagellates

T rypanosomaT rypanosoma

spp.spp.

Sleeping sicknessSleeping sickness

Chagas¶ diseaseChagas¶ disease



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EuglenozoaEuglenozoaMove by flagellaMove by flagella

PhotoautotrophsPhotoautotrophs EuglenoidsEuglenoids

ChemoheterotrophsChemoheterotrophs

N aegleriaN aegleria Flagellated and amoeboid forms, meningoencephalitisFlagellated and amoeboid forms, meningoencephalitis

T rypanosomaT rypanosoma Undulating membrane, transmitted by vectorsUndulating membrane, transmitted by vectors

LeishmaniaLeishmania Flagellated form in sand fly vector, ovoid form inFlagellated form in sand fly vector, ovoid form invertebrate hostvertebrate host



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Slime MoldsSlime Molds

Not obvious pathogens.Not obvious pathogens.

Cellular slime molds resemble amoebasCellular slime molds resemble amoebas

and ingest bacteria by phagocytosis.and ingest bacteria by phagocytosis. Plasmodial slime molds consist of Plasmodial slime molds consist of

multinucleated mass of protoplasm thatmultinucleated mass of protoplasm that

engulfs organic debris and bacteria as itengulfs organic debris and bacteria as it

moves.moves.

All can produce large fruiting bodies. All can produce large fruiting bodies.



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HelminthsHelminths

Parasitic flatworms belong to the PhylumParasitic flatworms belong to the Phylum

Platyhelminthes.Platyhelminthes.

Parasitic roundworms belong to theParasitic roundworms belong to thePhylum NematodaPhylum Nematoda



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Characteristics of HelminthsCharacteristics of Helminths

Are Multicellular animals, few are Are Multicellular animals, few are

parasites.parasites.

Parasites have modified life cyclesParasites have modified life cycles Only the adult is found in the definitive host.Only the adult is found in the definitive host.

Larval stage requires an intermediate host.Larval stage requires an intermediate host.

Can be monoecious or dioeciousCan be monoecious or dioecious



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PlatyhelminthsPlatyhelminths

Flatworms, lack a digestive system obtainFlatworms, lack a digestive system obtain

food by absorption across the outer food by absorption across the outer

surface.surface.

Flukes and trematodes have suckers thatFlukes and trematodes have suckers that

help them attach and feed on host tissue.help them attach and feed on host tissue.

Cestode or tapeworm consists of scolexCestode or tapeworm consists of scolex

and proglottids.and proglottids.



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HumansHumans

Definitive host for beef tapeworm (cattle areDefinitive host for beef tapeworm (cattle are

intermediate)intermediate)

Human definitive and intermediate host for Human definitive and intermediate host for

pork tapeworm.pork tapeworm.

Intermediate for Intermediate for E chinococcus granulosusE chinococcus granulosus thethe

definitive hosts are dogs, wolves and foxes.definitive hosts are dogs, wolves and foxes.



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CestodesCestodes

Figure 12.27



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NematodesNematodes

Roundworms have a complete digestiveRoundworms have a complete digestive

system.system.

Infect humans with their eggs areInfect humans with their eggs are

E nterobius vermicularisE nterobius vermicularis pinworm andpinworm and

Ascaris lumbricoides Ascaris lumbricoides

T richinella spiralisT richinella spiralis

N ecator americanusN ecator americanus (hookworm)(hookworm)



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Arthropods Arthropods

Jointed legged animals, including ticks andJointed legged animals, including ticks and

insects belong to the Phylum Arthropodainsects belong to the Phylum Arthropoda

Ones that carry disease are called vectorsOnes that carry disease are called vectors

Can eliminate disease be eliminatingCan eliminate disease be eliminating

vectors.vectors.



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Antiprotozoan Drugs Antiprotozoan Drugs

Chloroquine inhibits DNA synthesis, MalariaChloroquine inhibits DNA synthesis, Malaria

Metronidazole, damages DNA, Entamoeba,Metronidazole, damages DNA, Entamoeba,

TrichomonasTrichomonas

Antihelminthic Drugs Antihelminthic Drugs

Niclosamide, prevents ATP generation inNiclosamide, prevents ATP generation in

mitochondria, Tapeworm infections.mitochondria, Tapeworm infections.



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Ch 5 Euk Microbes