Chapter 5: The Eukaryotes of Microbiology

What is the cause of malaria?

Plasmodium

Name some diseases caused by protozoa

• malaria, amobiasis, giardiasis, toxoplasmosis

• trichomoniasis, leishmaniasis, cryptosporidiosis, dysentery

What nematode causes ascaris lumbricoides?

ascardiasis

Name some diseases caused by nematodes

• ascariasis, trichuriasis, hookworm, enterobiasis, strongyloidiasis

• filariasis, trichinosis, dirofilariasis, angiostrongyliasis

What fungi causes valley fever (coccidioidomycosis)?

The fungus coccidioides

Name some diseases caused by fungi

• aspergillosis, blastomycosis, ringworm, candidiasis, cryptococcosis

• histoplasmosis, valley fever, meningitis, tinea versicolor

How do protists/protozoa act?

Animal-like

Characteristics of protozoa

• Motile

• Unicellular

How do algae act?

Plant-like

Characteristics of algae

• photosynthetic

• uni/multicellular

How do molds act?

Fungus-like

Characteristics of molds

• multicellular

What do some protozoa have?

Some have a host-stage, some are symbiotic and beneficial and a plasma membrane

What is a term to describe the active feeding and growth of protozoans?

trophozoite

What happens to protozoans as they continue their life cycle?

Some remain in trophozoite form while others develop an encapsulate cyst (under stress)

• ex. eimeria

What motile parts do protozoans have?

Some may have flagella or cilia, even pseudopodia

What feeding structures do some protozoans have?

Contractile vacuoles, not all have mitochondria

Why is taxonomy difficult for protozoans?

It is difficult because not all protozoans share a common ancestor

What three subgroups will we focus on in this class?

1. Amoeba

2. Excavata

3. Chromaveolata

How do amoebozoa move?

pseudopods

What does Entamoeba Histolytica cause?

Causes amebic dysentery

What does Acanthamoeba cause?

Infects cornea → blindness

What does Balamuthia cause?

Granulomatous Amebic Encephalitis

What do chromalveolata include?

• Apicomplexa

• Ciliates

• Diatoms

• Dinoflagellates

What kind of life cycle do Apicomplexans have?

A complex life cycle

What is life cycle of apicomplexans?

1. infect sporozoites

2. undergo schizogony to make merozoites

3. often multiple hosts

4. intra and extracellular parasites

What is Toxoplasma Gondii transmitted by and what does it cause?

1. Transmitted by cats

2. Causes fetal infections and brain lesions

What is Cryptosporidium Parvum transmitted by and what does it cause?

1. transmitted via feces

2. causes waterborne illness

What is plasmodium transmitted by and what does it cause?

1. Transmitted by mosquitos

2. Fever, diarrhea, seizures

What is the 1st step of the life cycle of a Plasmodium Vivax?

Infected mosquito bites human; sporozoites migrate through bloodstream to liver of human

What is the 2nd step of the life cycle of Plasmodium Vivax?

Sporozoites undergo schizogony in live cell; merozoites are produced

What is the 3rd step of the life cycle of a Plasmodium Vivax?

Merozoites released into bloodstream from liver may infect new red blood cells

What is the fourth step of the life cycle of a Plasmodium Vivax?

Merozoites develops into ring stage in red blood cell

What is 5th step of life cycle of Plasmodium Vivax?

Ring stage grows and divides, producing merozoites

What is the 6th step of the life cycle of a Plasmodium Vivax?

Merozoites are released when red blood cell ruptures; some merozoites infect new red blood cells and some develop into male and female gametocytes

What is the 7th step of the lifecycle of a Plasmodium Vivax?

Another mosquito bites infected human and ingests gametocytes

What is the 8th step of the life cycle of a Plasmodium Vivax?

In mosquito’s digestive tract, gametocytes unite to form zygote

9th step of the life cycle of a Plasmodium Vivax

Resulting sporozoites migrate to salivary glands of misquito

In ciliophora, what are arranged in precise rows?

Cilia

What is the name of the only human ciliate parasite and what does it cause?

Balantidium Coli

• causes dysentery

What is unique about the supergroup Excavata?

They have complex cell shapes and structures

What do Excavata include?

• Fornicata

• Parabasalia

• Euglenozoa

What do Fornicata lack but have?

• lack mitochondria

• have flagella

What is Giardia lamblia?

A fornicata that spreads through cysts in feces that contaminate water supplies and causes diarrhea

• Fornicata

What is Trichomonas Vaginalis cause?

Includes trichomoniasis; Causes STD

• Parabasalia

Why are parasitic helminths (worms) included in microbiology?

They are included because they have microscopic eggs and larvae

Characteristics of helminths

• multicellular w/ organ systems

• complex life cycle w/ multiple hosts

What are the two major types of parasitic helminths?

• Roundworm (Phylum Nematoda)

  • Pinworm

  • Hookwork

• Flatworm (Phylum Platyhelminthes)

  • Cestodes (tapeworms

  • Trematodes (flukes)

Characteristics of Phylum Nematoda

• Unsegmented worms

What is Ascaris Lumbricoides?

Intestinal parasite

What is Enterobius Vermicularis and what does it cause?

• pinworm infection

• causes sleepiness, itchiness around anus

What are two nematodes found in cats and dogs?

Toxocara canis & T. Cacti

What is Trichinella Spiralis cause and how is it obtained?

• causes trichinosis

• eating undercooked meat, larvae infect muscles

How is dirofilariaimmitis transmitted and what does it cause?

• Transmitted by mosquitos

• Causes heartworms in dogs

What group are trematodes under?

Phylum Platyhelminthes

Characteristics of trematodes (flukes)

• Unsegmented, oral sucker

  • attach to inner wall of intestines, lungs, blood vessels or liver

What does Paragonimus Westermani cause?

Causes lung fluke

What group do Cestodes fall under?

Phylum Platyhelminthes

Characteristics of Cestodes

Segmented worms with suckers or hooks at the head region to attach to inner walls of small intestines

Kingdom fungi characteristics

• hyphae

• mycelium

• thallus

• septate

• chitin cell wall

• spore forming (haploid stage)

What groups of fungi will we focus on?

1. Zygomycota

2. Ascomycota

3. Basidiomycota

4. Microsporidia

What virus is under zygomycota?

Rhizopus Stolonifera - bread mold or strawberries and raspberries

What are edible under ascoymycota (sac fungus)?

Mushrooms, morels, and truffles

Characteristics of Ascomycota

• septate hyphae

• cup-shaped fruiting bodies (ascocarps)

• sexual reproduction via ascospores, often using asay’s

• asexual reproduction via conidia

What is Aspergillus?

Causes allergies and infections

• Aspergillus Flavus produces aflatoxin (most potent carcinogen)

What does Penecillium produce?

Antibiotics

What are the 3 dermatophytes?

• Trichophyton

• Microsporum

• Epidermophyton

What does Blastomyces Dermatitidis cause?

Respiratory infections

What does Coccidioides immitis cause?

Valley Fever

What does Candida Albicans cause?

Yeast infections

What are Saccharomyces?

yeasts, unicellular, used for brewing and baking

What are edible in Basidiomycota (club fungus)?

Mushrooms, morels, and truffles

Characteristics of basidiomycota

• septate hyphae

• fruiting bodies (basidiocarps) contain basidia (club-shaped)

  • sexual reproduction of basidiospores (haploid)

Where is Cryptococcus Neoformans found and what can it cause?

• found as yeast in environment

• cause serious lung infections when inhaled by individuals with weakened immune systems

What is Amanita Phalloides?

A poisonous mushroom known as the death cap

What has never been observed in microspordia?

Sexual reproduction

• likely occurs in host

Characteristics of micrspordia

• no mitochondria

• spore producing

  • they release polar tubules that pierce the host’s cells

• obligate intracellular parasites

What are infections with microsporidia called?

Microsporidiosis

Example of microsporidiosis

Encephalitozoon Bieneusi

• causes diarrhea, cholecystitis, and infections rare cases, causes respiratory illness