1. The Eukaryotic Members of the Microbial World
Chapter 12

2. Algae Diverse group of eukaryotic organisms
Use light to convert carbon dioxide and water to carbohydrates
Includes both microscopic unicellular and macroscopic multicellular organisms

3. Algae Classification of algae Algae not a distinct classification term
Grouped for identification based on numerous properties
Photosynthetic pigments
Cell wall structure
Type of storage products
Mechanism of motility
Mode of replication
Names are derived from major color displayed by group

4. Algae Algal habitats Found in both fresh and salt water and soil
Aquatic algae major producers of oxygen
Also important users of carbon dioxide
Algae often grow where other life forms can’t
Often first to become established in barren environments

5. Algae Structure of algae Can be both micro and macroscopic
Can float free or be propelled by flagella or filaments
Macroscopic algae are multicellular
Contain numerous structures for specific functions
Holdfast anchors organism to firm substrate
Stapes hold blades which are the major photosynthetic portion of algae
Gas-containing bladders to help maintain blades in proper position for maximum sunlight

6. LE 28-18
Blade
Stipe
Holdfast

7. Kelp Forest

8. Algae Structure of algae Cell wall Cell structures
Rigid structure made mostly of cellulose
Diatoms have silicon dioxide incorporated in cell wall
Cell structures
Have membrane bound nucleus containing DNA
Have both chloroplast and mitochondria
Chloroplast for photosynthesis
Mitochondria for respiration

9. Diatom (hatbox with lid)

10. Algae Algae reproduction
Most single cell algae reproduce through binary fission
Chromosome goes through mitosis
Some algae reproduce through fragmentation
Portion of parent organism breaks off to form new organism
Sexual reproduction through meiosis also occurs

11. Algae Algae do not cause disease directly Numerous algae produce toxin
Toxins are poisonous to humans
Some species such as dinoflagellates produce neurotoxins
Dinoflagellates eaten by shellfish and produce toxin
Toxin accumulates in shellfish tissues
Human eat shellfish and suffer paralytic shellfish poisoning

12. Protozoa Microscopic unicellular organisms
Lack photosynthetic capability
Usually motile
Reproduce by asexual fission

13. Protozoa Classification of protozoa Not a unified group
Lumped together as unicellular organism lacking chlorophyll
Traditionally divided into groups based on mode of locomotion
Some belong to phylum Sarcomastigophora
Includes two subphyla
Mastigophora- a subphylum of protozoans comprising forms typically having one or more flagella and reproducing asexually usually by binary fission
Sarcodina - characterized by the formation of pseudopods for locomotion and taking food

14. Protozoa Classification of protozoa Mastigophora Sarcodina
Includes flagellated protozoa
Most significant include
Giardia lamblia, Leshmania species Trichomonas vaginalis and Trypanosoma species
Sarcodina
Move by means of pseudopodia
Entamoeba hystolytica produces disease in humans (Explosive diarrhea, liver infection, death)

15. Giardia lamblia Transmission: Drinking water containing cysts
Symptoms include loss of appetite, lethargy, fever, explosive diarrhea, loose or watery stool, stomach cramps, upset stomach, bloating, and flatulence.

16. Leshmania Transmission: Inoculation by sandfly vector
Cutaneous Leishmaniasis
Visceral Leishmaniasis
Mucocutaneous Leishmaniasis

17. Trichomonas vaginalis
Characteristic halo around the nucleus of cells from PAP smear

18. Trichomonas vaginalis, an anaerobic, parasitic flagellated protozoan, is the causative agent of trichomoniasis, and is the most common pathogenic protozoan infection of humans. The estimates for North America alone are between 5 and 8 million new infections each year

19. Trypanosoma – African Sleeping Sickness
tsetse fly

20. Sarcodina - the amoeba
amebic dysentary is caused by the protozoan Entamoeba histolytica
Intestinal abscess caused by Entamoeba histolytica
feed on intestinal contents and host tissue

21. Protozoa Classification of protozoa Other phylum include Ciliophora
Organism have cilia
Balantidium coli only pathogenic ciliate
Ulcerative colitis
Apicomplexa
Cause most serious protozoan disease
Plasmodium species causes malaria
Microspora
Cause severe infection in immunocompromised

22. Plasmodium falciparum

23. Balantidium coli

24. Protozoa Protozoan habitats Majority are free-living
Found in marine, fresh water and terrestrial habitats
Essential decomposers
Require large amounts of moisture
Important part of food chain
Protozoa eat bacteria and serve as food for larger species
Help maintain ecological balance in soil
Important in sewage disposal
Results in decrease of sewage solids

25. Protozoa Structure of protozoa Cell wall Cell structures
Lack cell wall
Shape determined by material beneath plasma membrane
Cell structures
Have membrane bound nucleus and organelles
Lack photosynthetic chloroplasts
Have specialized structures for movement
Cilia, flagella or pseudopodia
Protozoa grouped by mode of locomotion

26. Protozoa Life cycles complex
schizogony
Protozoa
Protozoan reproduction
Life cycles complex
Often require more than one habitat or host
Polymorphic
Can exist as trophozoite or as cyst, i.e. Active feeding vs vegetative state
Both sexual and asexual reproduction common
Many replicate via binary fission
Many replicate by schizogony
Many fissions
Nucleus divides numerous times then cell produces numerous single celled organisms

27. Fungi Describes a taxonomic classification of organisms
No longer includes slime molds and water molds
Fungi require organic compounds for energy and as a carbon source
Most are aerobic or facultative anaerobe
Large number of fungi cause disease in plants
Only a few cause disease in humans

28. Fungi Classification of fungi Can be both micro and macroscopic
Cell wall consist of chitin
No flagellated cells
Four groups of true fungi
Zygomycetes
Basidiomycetes
Ascomycetes
Deuteroomycetes
A.k.a fungi imperfecta
Classification in groups based on sexual reproduction
Except where sexual reproduction is not seen

29. Fungi Classification of fungi Zygomycetes Ascomycetes Basidiomycetes
Includes common bread mold Rhizopus
Ascomycetes
Includes the fungi of Dutch elm disease
Basidiomycetes
Includes common mushroom and puffballs
Deuteromycetes
Includes medically and commercially important species including the penicillium mold

30. Penicillium notatum Penicillium Conidiophores
Condia - an asexual spore formed by abstriction at the top of a hyphal branch

31. Fungi –Science of mycology
Classification of fungi
Grouping of fungal forms
Yeasts
Single celled fungi
Spherical, oval or cylindrical
Reproduction through binary fission or budding
Molds
Filamentous fungi contain hyphae  collection of hyphae called mycelium
Reproductive spore is single celled  germinates to develop hyphae  cells divide into new form
Dimorphic fungi
Can grow as yeast or mold depending on environment
Many pathogenic fungi are dimorphic

32. Fungi Fungal habitats Growth requirements of fungi
Found in virtually every habitat
Mainly terrestrial
Fungal spores found throughout the earth
Uncountable numbers found in air
Major cause of asthma
Growth requirements of fungi
Slightly moist environment with high humidity
70% or higher
pH range varies
Most grow well in slightly acidic environment
Most are aerobic
Some yeast facultative
Some fungi obligate anaerobes

33. Fungi Fungal diseases in humans Cause disease in one of four ways
Allergic reaction
Result from inhaling fungal spores
React to fungal toxin
Many have hallucinogenic properties
Certain species produces alflatoxin implicated in cancer
Mycoses
Fungi grows on or in the body
Economic impact
Destroy human food supply causing starvation

34. Ringworm Fungus (tinea corporis)

35. Ringworm Fungus (tinea corporis)
This 7-year-old boy had multiple widespread annular plaques ranging from 1-5 cm in diameter. These lesions had been progressing for 6 weeks. His mother had 4 similar plaques on her left arm for 2 weeks. A potassium hydroxide preparation obtained from the scaly border on one of the mother's lesions was loaded with branching hyphae. The boy was treated with oral griseofulvin, and his mother cleared with a topical antifungal cream. Just before the eruption began the family purchased pet white rats, and both were noted to have itchy scaly patches.

36. Tinea pedis –Athletes foot

37. My Foot Fungus Author unknown
I'm growing fungus on my feet. To tell the truth, it's kinda neat. I grew it for my micro class. It's got so big, I'm bound to pass.
But it's not easy growing mold. You must keep it dark and from the cold. Put your socks on when they're wet, And feed your fungus lots of sweat
It's been a month since I last showered, And because of this, it's truly flowered. It's amazing just how fast it grows. You've never seen such fuzzy toes!
It has the most delightful hue. It's sorta green and sorta blue.
But there are drawbacks to fungal riches.
You won't believe how much it itches. And the smell is gross, but I must say, “It's worth it all to get an "A''.

38. Tina cruris – Jock itch

39. Fungi Symbiotic relationships of fungi
Form several symbiotic relationships with other organisms
Lichens result from relationship between fungi and photosynthetic organisms (Algae)
Relationships are very close
Fungus provides protection and growing platform
Other organism supplies nutrient
Mycorrhizae symbiosis with roots of plants
Increases absorptive property of roots
Allow plant partners to grow in dryer climates

40. Fungi Economic importance of fungi Many are important commercially
Saccharomyces used in production of beer, wine and bread
Many important for cheese production
Penicillin, griseofulvin antibiotic, as well as other antimicrobials are made from fungi
Elimination of disease causing fungi from commercial crops vitally important
Fungi used in genetic and biochemical studies
Yeast genetically engineered to produce human insulin

41. Corn smut fungus

42. Slime Molds and Water Molds
Used to be considered types of fungi
They are completely unrelated
Good example of convergent evolution
Two organisms develop similar characteristics and adaptations but not related on molecular level

43. Slime Molds and Water Molds
Acellular slime molds
Terrestrial organisms
Non motile
Reproduction depends of formation of dispersible spores
Acellular slime molds readily visible in environment
Plasmodium formed from nucleus spreads over surface of decaying matter
Cellular slime molds
Has vegetative form made of ameba-like cells
Single cells congregate into form called slug
Slug forms fruiting body and spores

44. Slime Molds and Water Molds
A.k.a Oomycetes
Members of heterokonts
Do not have chlorophyll
Once considered fungi
Due to morphology
Form masses of white thread on decaying matter
Zoospores cause serious disease of food crops

45. Multicellular Parasites: Arthropods and Helminths
Arthropods include
Insects such as mosquitoes responsible for transmission of malaria and fleas which transmits plague
Ticks responsible for transmission of Rocky Mountain Spotted Fever and Lyme disease
Lice responsible for transmission of typhus and other fevers
Mites transmit scabies
Helminths include nematodes, cestodes and tremetodes
Cause disease by invading host tissues and robbing nutrients
Nematodes invade gastrointestinal tract and blood stream
Cestodes associated with meats especially pork (tapeworms)
Transmission results from consumption of uncooked meat
Trematodes
Can be found discharged in waters such as lakes and ponds

46. Arthropods Phthirus pubis
skin inflammation caused by tiny lice (Pediculus)

47. Ascaris lumbricoides
A mass of large round worms from a human infestation.

48. Tapeworm

49. Dipylidium caninum (Tapeworm)
A tapeworm found in fish contains a chemical compound that appears to make the fish infertile.
It seems to interfere with the fishes' hormone production, so females do not produce eggs and males do not produce sperm.
Researchers from Keele University say this chemical could form the basis of a contraceptive for humans that both men and women could use.
28 ft. tapeworm

50. Parasite Infection: Female Pinworms Leaving the Anus of a 5-year-old child to lay eggs on the adjacent skin