The document summarizes key information about eukaryotes including fungi, algae, protozoa, and helminths. It describes their structures, life cycles, and importance as pathogens. Fungi decompose organic matter and include molds, yeasts, and lichens. Algae include seaweeds, diatoms, and dinoflagellates. Protozoa are single-celled eukaryotes including parasites like Plasmodium and Giardia. Helminths are parasitic worms including tapeworms, flukes, and roundworms. Many have complex life cycles involving multiple hosts.

1. Chapter 12: The Eukaryotes: Fungi, Algae, Protozoa, Helminths Mycology is the study of fungi Mycosis = fungal disease All fungi are Chemoheterotrophs – live on preformed organic matter Excrete extracellular enzymes to digest organic matter and break it down to simple products that it absorbs Major decomposer of dead plant matter which recycles elements Ex. Cellulase: cellulose (plants, wood) to glucose used for energy Most are aerobic (molds) or facultative anaerobes (yeasts)

2. Molds and fleshy fungi - multicellular Thallus = body consist of long filaments of cells joined together = hyphae Septate – partitions between cells, may have pores between cells so cytoplasm mixes with adjacent cells, 1 or 2 nuclei/cell Coencytic = non septate, many nuclei Hyphae grow by elongating at tips, fragmentation Vegetative hyphae – obtains nutrients Aerial hyphae- bears reproductive spores Mass of hyphae = mycelium Cell walls contain chitin , same as exoskeletons of arthropods ex Insects

3. Yeasts - unicellular Budding (reproduction) – yeast forms a bud on its surface that elongates Parent cell nucleus divides, one nucleus migrates into the bud Cell wall forms between yeast and bud and bud breaks off Pseudohyphae = buds fail to detach and from a short chain of cells Candida albicans – attaches to epithelial cells as yeast but forms pseudohyphae to invade deeper into tissue

4. Yeasts - unicellular Capable of facultative anaerobic growth Aerobic respiration Yeast + O2 metabolize CH2Os to CO2 + H2O Anaerobic respiration Yeasts without O2 ferments CH2Os to ethanol and CO2 Brewing, wine making, baking industries

5. Saccharomyces cerevisiae

6. Dimorphic fungi – most are pathogenic Dimorphism = 2 forms of growth – yeast or mold Temperature dependent Moldlike at 25 degrees C Yeasts at 37 degrees C Life cycle Filamentous fungi can reproduce asexually – fragmentation or spores and reproduce sexually by spores Fungal spores can survive hot, dry environments but not like endospores Asexual spores – produced by hyphae of a single fungus Conidiospores = conidium (pl. conidia) = uni or multicellular spores not enclosed in a sac

7. Asexual spores Conidiospores Pg 349 Produced in a chain at the end of a coniophore ex. Aspergillus Arthroconidia – formed by fragmentation ex. Coccidiodes immitis – pulmonary mycoses Blastoconidia buds coming off parent cell – some yeasts ex. Candida albicans, Cryptococcus (lungs)

8. Asexual spores Chlamydoconidium – spore formed within a hyphal segment ex. Candia albicans Sporangiospore – spore formed in a sac = sporangium at the end of an aerial hyphae called a sporangiophore ex. Rhizopus

9. Conidiospores - Aspergillus

10. Sexual reproduction Sexual spores result from the fusion of nuclei from 2 opposite mating strains Pg. 350 shows both asexual and sexual reproduction in Rhizopus

11. Classification of fungi by phylum Zygomycota = conjugation fungi, bread molds ex. Rhizopus stolonifer Hyphae = coenocytic Asexual reproduction = sporangiospores Sexual reproduction = zygospores = thick walled spores formed from union of 2 opposite mating strains Habitat = soil, saprophytic = lives on decaying plant material

12. Classification of fungi by phylum Ascomycota - sac fungi ex. Aspergillus niger (used to make Beano), Penicillium (Abs) Hyphae – septate, some yeasts Asexual reproduction = conidia (means dust, becomes airborne) Sexual reproduction = ascospores which are contained in an ascus Habitat = soil, saprophytic

13. Classification of fungi by phylum Basidiomycota – club fungus , mushrooms ex. Cryptococcus neoformans (inhalation of spores causes lung disease) Hyphae = septate Asexual reproduction = fragmentation Sexual reproduction = basidiospores Habitat = soil, bird feces

14. Fungal infection = mycosis 5 classifications Systemic mycoses – infection deep within the body Can infect a # of tissues and organs Transmission – inhalation of spores Enters the lungs and then spreads to other body tissues Not contagious Live in soil Histoplasmosis and coccidiodomycosis – both pulmonary mycosis

15. Fungal infection = mycosis 5 classifications Subcutaneous mycoses – infection beneath the skin caused by saprophytic fungi that live in the soil and on vegetation Transmission – by direct implantation of spores or hyphae into puncture wounds Cutaneous mycoses Dermatophytes = fungi that live only on epidermis, hair, nails Secrete enzyme keratinase wh/ degrades keratin in hair, skin, nails Transmission – direct contact – human to human, animal to human

16. Subcutaneous Mycoses

17. Superficial Mycosis

18. Superficial Mycosis

19. Fungal infection = mycosis 5 classifications Superficial mycosis – along hair shafts, surface epidermal cells, found in the tropics ex. Ringworm Opportunistic pathogen – normally harmless but is pathogenic in debilitated host , ex. Ab tx, lung disease, immune disorder Pneumocystis – leading cause of death in AIDS px Mucormycosis – Rhizopus , Mucor – px w/ diabetes, leukemia, or being txed w/ immunosuppressive drugs

20. Fungal infection = mycosis 5 classifications Opportunistic pathogen cont. Aspergillosis – Aspergillus – px w/ lung disease, cancer who have inhaled the spores Cryptococcus and Penicillium – can be fatal to AIDS px Yeast infections (candidiasis) – Candida albicans – occurs vaginally or as thrush in newborns, AIDS px, or px on Abs

21. Superficial Mycosis Ringworm, stained preparation, macroconidia of Microsporum canis

22. Superficial Mycosis Ringworm

23. Lichens Are a combination of a a green alga or a cyanobacterium and a fungus growing together in a mutualistic relationship – both benefit The algae provide the nutrients and the fungi provide attachment and protection from desiccation Provides erythrolitmin - dye used in litmus paper

24. Lichens Are used for indicator organisms for air pollution Some lichens cause allergic contact dermatitis in humans Major food source for caribou and reindeer After the 1986 Chernobyl nuclear disaster, lichens absorbed radioactive cesium -137 from the air and 70,000 reindeer raised for food in Lapland had to be destroyed

25. Algae Are unicellular or multicellular Habitat – aquatic, soil, trees, hair of sloths or polar bears Algae phyla Phaeophyta – brown algae = kelp – macroscopic in coastal waters Algin –thickener used in foods extracted from CW Rhodophyta = red algae –live at greater ocean depths than other algae Lab agar comes from red algae Carrageenan and agar used as thickening ingredients in foods and pharmaceutical agents

26. Algae Phyla Chlorophyta = green algae – usually microscopic, contains chlorophyll a and b Believed to have given rise to terrestrial plants Unicellular or multicellular - can form filaments Bacillariophyta = diatoms Unicellular or filamentous w/ CWs of pectin and silica that fit together like a Petri dish One of major algae in the oceanic food chain (phytoplankton) Used as polishing and insulating materials Diatomaceous earth – filtering material

27. Algae Phyla Dinoflagellata = dinoflagellates Unicellular algae, major part of phytoplankton Some produce neurotoxins and are responsible for many fish, marine mammals and some human deaths Large concentrations – ocean deep red color = red tide Mollusks shouldn’t be harvested during a red tide- concentrates neurotoxin and causes paralytic shellfish poisoning

28. Algae Phyla Oomycota = water molds pg 360 pix Decomposers that form cottony masses in fresh H2O Used to be classified as fungi but DNA analysis confirms they are more closely related to diatoms and dinoflagellates Responsible for Ireland’s great potato blight in 1800’s – millions died Zoospores = flagellated spores w/ 2 flagella Causes mildew on grapes, effects fruit and veg crops

29. algae 80% of Earth’s O2 is produced by planktonic algae as a by product of photosynthesis Increase in numbers of planktonic algae causes algal blooms When algae die in large numbers their decomposition depletes the level of dissolved O2 in the H2O – may kill fish

30. Protozoa = 1 st animal single celled Trophozoite = feeding or growing stage Reproduce asexually by fission, budding or schizogony (multiple fission) Sexual reproduction in some protozoa Ex. Ciliate - Paramecium by conjugation see pg. 362 fig. 12.16 Can form cyst stage to survive when food, moisture, O2 are lacking, temp not right, toxic chemicals are present Cysts can survive outside the host when excreted – ready for new host

31. Protozoa Are aerobic heterotrophs but many intestinal protozoa are capable of anaerobic growth

32. Medically important Phyla of protozoa chart pg 367 Archaezoa – eukaryotes that lack mitochondria 2 or more flagella – whip like Trichomonas vaginalis – urinary and genital tract infections Has undulating membrane (pg 363) and no cyst stage Transmitted by sexual intercourse, toilet seats, towels Giardia lamblia (intestinales) – found in small intestine of mammals Excreted in feces as cysts to be ingested by next host Dx = id cysts in feces

33. Medically important Phyla Microspora – obligate intracellular parasites that also lack mitochondria Cause chronic diarrhea and keratoconjuctivitis (inflammation of the conjunctiva) esp. in AIDS pxs Amoebozoa – move and engulf food by pseudopods Entamoeba histolytica – only pathogenic amoeba found in human intestine – 10% pop. May be infected Causes amoebic dysentery Transmitted by ingestion of cyst excreted in feces

34. Medically important Phyla Acanthamoeba Can grow in tap water and infects the cornea of the eye and cause blindness Apicomplexa – intracellular parasites whose life cycle involves several hosts Ex. Plasmodium vivax causes malaria, transmitted to humans by female Anopheles mosquito

35. Life cycle of Plasmodium pg 365 Definitions: Trophozoites – feeding or growing stage Sporozoites – in mosquito Merozoites – in humans Intermediate host - organism that harbors the larval or asexual stage Definitive host – organism that harbor the adult, sexually mature form of parasite

36. Life cycle of Plasmodium in humans Humans – intermediate hosts, asexual reproduction takes place Liver – mosquito bite infects human w/ sporozoites wh/ travel thru the blood into the liver Sporozoites are removed from the blood and enter the liver cells They undergo asexual reproduction or schizogony to form 1000s of merozoites

37. Life cycle of Plasmodium in humans Humans Merozoites leave the liver to infect RBCs RBCs Merozoites infect and reproduce in RBCs The RBCs then rupture and release merozoites which infect more RBCs Their waste products cause the fever and chills characteristic of malaria when RBCs rupture Some merozoites develop into gametocytes (male, female)

38. Life cycle of Plasmodium in Mosquitos Mosquitos – definitive hosts , sexual reproduction takes place Mosquito picks up gametocyte when bite infected human Gametocyte travel to mosquito intestine and begin sexual cycle Gametocytes unite to form a zygote wh/ forms an oocyst where sporozoites are formed Sporozoites migrate to the mosquito salivary glands where they are transmitted to human’s blood w/ the next bite

39. Apicomplexa continued Cryptosporidium – causes intestinal infection Transmission is by feces, H2O, nosocomial infections Toxoplasma gondii Intracellular parasite - causes toxoplasmosis Transmitted through cat feces and is dangerous for pregnant women Can cause problems in fetus including stillbirth

40. Medically important Protozoan Phyla Ciliophora – ciliates, cilia for movement and to bring food into mouth Balantidium coli – only ciliate that is a human parasite Cause severe dysentery Cysts excreted in feces Euglenozoa – 2 groups Euglenoids photoautotrophs

41. Phylum Euglenozoa Euglenoids cont. Pellicle = semi-rigid plasma membrane Anterior flagella, red eyespot that senses light Hemoflagellates –blood parasites transmitted by bites of blood feeding insects Have a long slender body and undulating membrane Trypanosoma brucei gambiense – causes African sleeping sickness from bite of tse tse fly Trypanosoma cruzi – causes Chagas’ disease – bite of kissing bug (face) – trypanosome in feces wh/ gets in bite

42. Helminths – parasitic worms Phylum Platyhelminthes = flatworms 2 groups = trematodes and cestodes Trematodes = flukes Flat, leaf shaped bodies, suckers to hold them in place, Paragonimus westermani – lung fluke pg 373 life cycle Adult lives in bronchioles of mammals where hermaphroditic adults lay eggs into the bronchi

43. Helminths – parasitic worms Paragonimus westermani cont . Sputum w/ eggs is coughed up, swallowed, and excreted w/ feces Eggs have to make it to H2O to find intermediate hosts (snail, crayfish) Transmission – ingestion of undercooked crayfish Dx –eggs in sputum or feces

44. Helminths – parasitic worms Cestodes = tapeworms Lack a digestive tract, absorb nutrients thru cuticle Scolex = head with suckers and hooks for attachment Proglottids = body segments wh/ are produced by neck of scolex Mature proglottids contain both male and female reproductive organs Those farthest from scolex are bags of eggs

45. Cestodes = tapeworms Humans as definitive hosts Taenia saginata – beef tapeworm Proglottids ingested by grazing animals Larvae migrate to muscle (meat) where they encyst as cysticerci If you eat infected meat all but the scolex is digested It anchors itself to the small intestine and starts producing proglottids

46. Cestodes = tapeworms Humans as definitive hosts cont. Taenia solium = pork tapeworm Adult worms in human intestines lay eggs that pass out w/ feces and are eaten by pigs Eggs hatch into larvae wh/ encyst in pigs muscles Transmission by eating undercooked pork – not in US Human-going in larvae-in adult- leaving eggs Eggs shed by 1 person and ingested by another – eggs hatch and encyst in brain and other body parts causing cysticercosis – now human intermediate host Human – eggs leaving – human eggs ingested – larvae hatch and encyst

47. Tapeworm Life Cycle

48. Cestodes = tapeworms Humans as intermediate hosts pg 375 Echinococcus granulosus = dog tapeworm Dogs, coyotes – definitive hosts Eggs transmitted by dog feces or saliva after dog licks self Eggs hatch in the small intestine and larvae migrate to liver or lungs Larvae develop into hydatid cyst wh/ contain brood capsules wh/ can produce 1000s of scoleces Sx = abdominal and chest pain, coughing up blood

49. Nematoda = roundworms Free-living and parasitic Cylindrical, tapered at each end Complete digestive system Most are dioecious (male and females) – males are smaller than females and have spicules on posterior end to guide sperm into female genital pore Human infection can be divided into whether the egg or larvae is infective

50. Nematode eggs infective for humans Enterobius vermicularis = pinworm Spends entire life in humans Adults in large intestine Female migrates to anus to lay eggs on perianal skin Eggs ingested by the same host or another person thru contaminated bedding or clothes Dx. Graham sticky-tape method

51. Pinworm Life Cycle

52. Pinworms on Perianal Folds

53. Nematode eggs infective for humans Ascaris lumbricoides – large (30 cm), infects over 1 billion ww Dioecious w/ sexual dimorphism = male and female different Male smaller w/ curled tail Adults live in small intestine of humans only Feed on semi-digested food Eggs excreted in feces > ingested by another host > hatch in sm intestine > burrow out of intestine and enter blood where they are carried to the lungs to grow > coughed up and swallowed and return to the Small Intestine to mature into adults (now can repro)

54. Nematode larvae infective for humans Necator americanus, Ancylostoma duodenale = adult hookworms that live in the small intestine of humans eggs are excreted in feces Larvae hatch in soil where they enter host by penetrating skin Larvae enter blood or lymph vessels and are carried to lungs > coughed up in sputum > swallowed and carried to small intestine Dx by eggs in feces, avoid by wearing shoes

55. Nematode larvae infective for humans Trichinella spiralis – causes trichinellosis by eating undercooked pork or game animals (bear) w/ larval cysts in ms Larvae are freed from cysts in small intestine > mature into adults > sexually reproduce > females give birth to live larvae wh/ enter lymph and BVs > they migrate to ms and other tissue where they encyst and remain until eaten by another host Dx = microscopic exam of larvae in ms biopsy Prevention = cook meat

56. Arthropods = Insects, Arachnids Have segmented bodies, hard external skeletons, jointed legs If carry pathogenic microorganisms = vectors table on pg 378 Mechanical vectors transport pathogens on feet or body ex. Flies Biological vectors - pathogens multiply in vectors and are transmitted thru saliva or feces

57. Body & Crab Lice