Chapter 12 Eukaryotic organisms

Mycology – study of fungi Heterotroph Absorb nutrients Yeasts – unicellular Molds – multicellular, filamentous Filaments – hyphae Fragment hypha can grow into a fungus

Aerial hyphae – reproductive spores Vegetative hyphae – absorb nutrients Cottony, fluffy

Yeasts – unicellular Oval or circular in shape Many reproduce by budding Buds fail to separate from the parent Pseudohyphae are formed Candida albicans

Dimorphic fungi Mold-like - 25o C Yeast-like – 37oC

Many fungi make asexual spores Different types of asexual spores

Septate hyphae – fragments Single cells - Thick cell walls Coccidiodes immitis

Pseudohypha – round and enlarged Candida albicans

Rhizopus

Conidiospores - Penicillium

Sexual reproduction Two different strains + and – Pheromones - proteins Attract negative strain – mate + and - fuse to make zygote Differentiates into a sexual spore Environmental conditions Nutrient depletion

Three groups of fungi Based on sexual spores Zygomycota Asexual spores – sporangiospores Sexual spores – zygospores Coenocytic hyphae Rhizopus

Ascomycota Some molds and some yeasts Molds – septate hyphae Asexual spores – conidiospores Yeasts reproduce by budding Sexual spores – ascospores Penicillium

Basidiomycota Mushrooms Septate hyphae Asexual – fragmentation of hyphae Sexual spores - basidiospores

Mycoses – fungal diseases Systemic mycoses – deep within the body Inhaling fungal spores Starts in the lungs – spreads to other parts Histoplasmosis – Histoplasma capsulatum Dimorphic fungus Conidiospores Soil enriched with bird droppings

Minor respiratory infection Immune system is weak – spreads to liver, spleen, bone marrow Coccidioidomycosis – Coccidiodes immitis Arthrospores – soil – southwest – abundant in the soil Cough, Chest pain Amphotericin B

Cutaneous mycosis – hair, nail, skin Ringworm, tineas Fungi – dermatophytes Keratinase – breaks down keratin Tinea pedis – athlete's foot Trichophyton rubrum Itching, scaling skin Direct contact, shower room floors

Opportunistic mycosis Candidiasis Candida albicans Normal flora Immune system weak Thrush – Candida infection of the oral cavity AIDS, newborns

Amanita phalloides Mushroom Death angel Neurotoxin Hallucinations Death within a week due to liver damage.

Claviceps purpurea Grows on grains – rye Toxin – ergot Ergotism Hallucination Constriction of the capillaries – gangrene Middle ages

Protozoa Unicellular – eukaryotic Soil, water, within the bodies of humans and animals. Trophozoites – metabolically active, reproduce, motile, inside the host Cyst – metabolically inactive, dormant, outside the host.

Entamoeba histolytica Pseudopods Intestinal tract Cysts are released in the feces. Contaminated food or water. Cysts – trophozoites – intestinal tract Feed on cells lining the intestinal tract, red blood cells. Dysentery – bloody diarrhea

Giardia lamblia Flagella Intestinal tract – carriers Cysts are released in the feces Trophozoits attach themselves to intestinal wall Abdominal pain, diarrhea, weight loss Metronidazole

Balantidium coli Cilia for movement. Macronucleus - controls protein synthesis Micronucleus – transmits genetic information Cysts are transmitted in contaminated food or water

Hemoflagellates Long, slender body Undulating (wavy) membrane Flagellum Trypanoasoma gambiense African sleeping sickness transmitted by tsetse fly Grows in the bloodstream Causes damage to the nervous system Drowsiness, coma, death

Trypanosoma cruzi Kissing bug Bug lives in the cracks and crevices of mud huts. Mexico, South America Damage to the nerves Chagas disease Mega colon, mega esophagus

Kinetoplast Mitochondrial DNA flagellum

Plasmodium Malaria Mosquito Chills, fever, vomiting Complex lifecycle Chloroquine

Algae Store energy –form petroleum diatoms

Dinoflagellates Plankton – free floating Aquatic environments – oceans Alexandrium – neurotoxin Mollusks – clams – eat a large amount of dinoflagellates - toxin is concentrated in clams People eat these clams – paralytic shellfish poisoning

Numbness of the mouth and lips Heat stable Ocean has a red tide

Helminths Worms Multicellular Eukaryotic Animal kingdom Do not have a well developed nervous system or digestive system. Do have a complex reproductive system. Platyhelminthes (flatworms) and nematodes (round worms)

Platyhelminthes Trematodes (flukes) Cestodes (tapeworms) Trematodes Flat leaf like body Hermaphroditic ( have both male and female reproductive organs – testes and ovaries) Intermediate host – immature worm (larvae), asexual reproduction Definitive host – mature worm (adult), sexual reproduction

Paragonimus westermani Lung fluke Bronchioles of infected humans and other animals. 12 mm long ( lives for 4 to 5 years) Chest pain, cough Praziquantel

Cestodes Intestinal parasites Head – scolex Scolex – hooks and suckers – attachment to the host. Segmented body Segments – proglottids Hermaphroditic

Taenia saginata – beef tapeworm Adult – human intestinal tract Eggs are released in the feces Cattle –ingest Larvae – cysts in the muscles (cysticerci) Transmitted to humans – undercooked contaminated beef. Intestinal tract – scolex comes out – develops into an adult worm.

18 feet 25 years Presence of eggs in the feces Abdominal discomfort Niclosamide

Taenia solium Adult – infected humans (definitive host) Eggs – feces Ingested by pigs ( intermediate host) Larvae - cysts in the muscles Undercooked contaminated pork More dangerous – humans can also become intermediate hosts.

Eggs can be ingested by humans Larvae form cysts in the muscles, brain Neurocysticercosis – “swiss cheese” Headache, convulsions, coma, death Poor sanitary practices Mexico, South America

Echinococcus granulosus Definitive host – dogs coyotes Eggs – feces Humans – poor sanitary practices Larvae – cysts – liver – lungs Cysts – hydatid cysts Humans – dead end – life cycle of the worm

Sheep herding population

Nematodes (roundworms) Dioecious – male and female worms. Enterobious vermicularis (pinworm) Intestine - female migrates to the anus Releases eggs – perianal area Itching in the area Mebendazole

Ascaris lumbricides Small intestine Feed on semidigested food eggs – feces Larvae – intestinal tract – migrate to the lungs – go back to the intestine – adult Obstruction of the intestinal tract

Necator americanus Intestinal tract Eggs –feces Larvae come out in the soil Penetrates the skin – intestinal tract Attaches to the intestinal wall – drink blood Anemia Prevention – wear shoes

Trichinella spiralis Undercooked encysted pork – larvae come out in the intestinal tract Female releases larvae Larvae form cysts in the muscles Diaphragm muscle Pigs – eating contaminated pork