1. Chapters 19,20,21 Start @ Chapter 19 Virus and Bacteria Microbiology

2. Viruses… The Living Dead? Living because… Living because… – Reproduce – Has DNA/RNA “Blueprint of Life” – Evolves Non-living because… Non-living because… – Require a host (Parasitic) – To reproduce, they use the host – It does not have cells

3. Sizes Most are so small they can’t be seen with normal microscopes Most are so small they can’t be seen with normal microscopes – Require Electron microscopes Are smaller than Monerans (Bacteria) Are smaller than Monerans (Bacteria)

4. Viral Shapes Spirals, Polygons, rods, bullets, needles Spirals, Polygons, rods, bullets, needles Bacteriophages Bacteriophages

5. Viral Parts Capsid: outer protein coat Capsid: outer protein coat – Allows the virus to enter a cell – “Tricks” the cell Genetic Material: DNA or RNA Genetic Material: DNA or RNA Envelope: Protective layer around the capsid. Envelope: Protective layer around the capsid. – NOT ALL VIRUSES HAVE THESE – Comes from the host cell membrane

6. Other facts about Viruses Almost all organisms have at least one virus that infects them Almost all organisms have at least one virus that infects them They are “host-specific” They are “host-specific” – Usually only infect one species

7. Types of Viruses Bacteriophages Bacteriophages DNA Viruses DNA Viruses RNA Viruses RNA Viruses Retroviruses Retroviruses

8. Bacteriophages Infect Bacteria Infect Bacteria Only Only

9. DNA Viruses Have DNA as their genetic material Have DNA as their genetic material Single-stranded DNA virus: Canine Parvovirus Double-stranded DNA virus: Chicken pox (Varicella zoster)

10. DNA Viruses DNA Viruses Herpes Virus in a host cell Human Papilloma virus: causes warts Adenovirus: causes some colds

11. RNA Viruses Has RNA as genetic material Has RNA as genetic material Rhinovirus: Common Cold Paramyxovirus: Measles and Mumps (in a host cell) Rabies virus

12. Retroviruses RNA as genetic material RNA as genetic material To replicate, they convert the RNA back into DNA and use host to make more RNA To replicate, they convert the RNA back into DNA and use host to make more RNA HIV (Human immunodeficiency virus)

13. How Viruses Infect Two ways it can happen Two ways it can happen Lytic Infection Lytic Infection Lysogenic Infection Lysogenic Infection

14. Lytic Infection (The Outlaw) Simple Version: Virus enters a cell, replicates, and bursts the cell Simple Version: Virus enters a cell, replicates, and bursts the cell

15. 1.Landing: Virus lands on Cell 2.Injection: Virus injects DNA into Cell 3.Replicate: Cell makes RNA out of Virus’s DNA, and shuts down Cell 4.Assemble: Cell then puts together the virus components 5.Burst: So many viruses are created that the cell lyses, or bursts.

16. Long Version Continued… – Cell Injects DNA into Cell – Cell makes RNA out of Virus DNA – That RNA then destroys the cell’s DNA – Shuts down the cell – Virus has free reign over cell and uses this to make 1000’s of copies – Cell machinery puts together the virus components – So many viruses form that the cell lyses, or bursts, with all the viruses free to visit other cells now.

17. Drawing

18. Lysogenic Infection Virus DNA is made indefinitely by the cell Virus DNA is made indefinitely by the cell Virus places its DNA into the host’s DNA so when replication happens it copies both the virus and the host Virus places its DNA into the host’s DNA so when replication happens it copies both the virus and the host Prophage:Viral DNA in the Host DNA Prophage:Viral DNA in the Host DNA Eventually will become Lytic Eventually will become Lytic

19. Drawing/Picture

21. Bacteria Prokaryotes: unicellular organisms that lack a nucleus Prokaryotes: unicellular organisms that lack a nucleus – Bacteria Prokaryotes are now classified as Monerans (Kingdom: Monera) Prokaryotes are now classified as Monerans (Kingdom: Monera) Divided into two groups: Eubacteria and Archaebacteria Divided into two groups: Eubacteria and Archaebacteria

22. Eubacteria Larger of the two kingdoms (in both size and variety) Larger of the two kingdoms (in both size and variety) Live almost everywhere Live almost everywhere Surrounded by a cell wall Surrounded by a cell wall – Cell wall contains peptidoglycan Other parts: Cell membrane & cytoplasm Other parts: Cell membrane & cytoplasm

23. Archaebacteria Same structure, different chemically Same structure, different chemically They lack peptidoglycan and have different membrane lipids They lack peptidoglycan and have different membrane lipids DNA sequence is more closely related to eukaryotes than eubacteria DNA sequence is more closely related to eukaryotes than eubacteria

24. Archaebacteria Live in extreme conditions Live in extreme conditions Examples: Examples: – Methanogens: Produce methane gas Live in stomachs and thick mud Live in stomachs and thick mud – Salty conditions – Boiling water – Sulfur pits – Etc…

25. Ways to Identify a Prokaryote Shape Shape Chemical Components of Cell Wall Chemical Components of Cell Wall Movement Movement Way they get Energy Way they get Energy

26. Shapes Coccus: Round bacteria Coccus: Round bacteria Example: Staphylococcus sp. Example: Staphylococcus sp.

27. Shapes Bacillus: rod bacteria Bacillus: rod bacteria – Example: Bacillus anthracis

28. Shapes Spirochetes: spiral bacteria Spirochetes: spiral bacteria – Example: Treponema pallidum

29. Cell Walls and Gram Staining Two different types are found in eubacteria Two different types are found in eubacteria We can pick them out using a method called Gram Staining We can pick them out using a method called Gram Staining – (We will do this if we get something to grow!)

30. Gram Staining Steps Two dyes: violet and red (counterstain) Two dyes: violet and red (counterstain) Violet: Applied first Violet: Applied first – Stains peptidoglycan in the cell wall Wash with alcohol Wash with alcohol – If color stays: Gram Positive – If color washes away: Gram Negative Red is then applied to make Gram Negative visible with pink color Red is then applied to make Gram Negative visible with pink color

31. Movement No movement No movement Flagella: Whip-like structure Flagella: Whip-like structure Lash Lash Snake Snake Spiral Spiral Glide Glide

32. Ways to Obtain Energy Two main groups Two main groups We have already talked about! We have already talked about! Heterotrophs: Energy by consuming others/organic molecules Heterotrophs: Energy by consuming others/organic molecules Autotrophs: Make their own food Autotrophs: Make their own food

33. Bacterial Heterotrophs Chemoheterotrophs: Obtain energy solely from organic molecules Chemoheterotrophs: Obtain energy solely from organic molecules – Most animals are this kind too! Photoheterotrophs: Photosynthetic, get energy from the sun but need others to get their carbon from Photoheterotrophs: Photosynthetic, get energy from the sun but need others to get their carbon from

34. Bacterial Autotrophs Photoautotrophs: Carryout photosyntehsis Photoautotrophs: Carryout photosyntehsis – Require light source – Ex: Cyanobacteria: chlorophyll a Chemoautotrophs: Carryout Chemosynthesis Chemoautotrophs: Carryout Chemosynthesis – Do not require light

35. Getting that Release Obligate aerobes: Requires oxygen Obligate aerobes: Requires oxygen – Ex: Mycobacterium tuberculosis Causes Tuberculosis Causes Tuberculosis Obligate anaerobes: Do not require oxygen Obligate anaerobes: Do not require oxygen – Ex: Clostridium botulinum Soil bacteria that can work its way into food if not properly sterilized! Soil bacteria that can work its way into food if not properly sterilized!

36. Special Release Facultative anaerobes Facultative anaerobes – Facultative: Function in different ways Can switch between living in oxygen or not (respiration or fermentation) Can switch between living in oxygen or not (respiration or fermentation) Means they could live practically everywhere Means they could live practically everywhere Ex: E. coli: Large intestine to sewage Ex: E. coli: Large intestine to sewage

37. Bacterial Reproduction (3 way) Binary Fission: Binary Fission: – Doubles in size, replicates DNA and divides in half. Conjugation: Conjugation: – Exchange of DNA between bacteria – Hollow tube connects bacteria – Responsible for genetic diversity

38. Spore Formation Occurs when environment is unfavorable Occurs when environment is unfavorable Endospore: thick internal wall that sections off the DNA with cytoplasm Endospore: thick internal wall that sections off the DNA with cytoplasm Spores can last until the conditions are acceptable to grow in Spores can last until the conditions are acceptable to grow in Ex: Bacillus antracis: Anthrax Ex: Bacillus antracis: Anthrax

39. Importance of Bacteria Producers that produce energy Producers that produce energy Decomposers: Decomposers: – If materials did not cycle in the environment, life would not exist – Sewage treatment: Turns trash into purified water, carbon dioxide, nitrogen, and fertilizers

40. Nitrogen fixers We’ve discussed this with the nitrogen cycle but lets see what we remember We’ve discussed this with the nitrogen cycle but lets see what we remember What do we need nitrogen for? What do we need nitrogen for? What is the process takes it from air? What is the process takes it from air? Symbiotic: Rhizobium and legumes Symbiotic: Rhizobium and legumes

41. Human Uses Bacteria is in food and beverages Bacteria is in food and beverages – Ex: Yogurt, Dairy products, Vinegar, Sausage, Pickles, anything that ferments (usually) Oil spills: Certain ones digest petroleum Oil spills: Certain ones digest petroleum Our Digestion: E. coli: Makes a number of vitamins that we cannot produce Our Digestion: E. coli: Makes a number of vitamins that we cannot produce

42. The Medical World Genetic Engineering Genetic Engineering Bacillus thuringiensis Bacillus thuringiensis – Main ingredient in Bt-Corn – Genetically engineered from soil bacteria to be placed into corn DNA – Kills insects by releases a toxin that affects insects and causes their stomachs to burst.

43. Only a few bad eggs… Most bacteria and viruses don’t harm Most bacteria and viruses don’t harm The ones that do are called PATHOGENS The ones that do are called PATHOGENS – Disease-causing agents Disease: result of pathogen infecting the host Disease: result of pathogen infecting the host

44. What do microorganisms need? Each species has an OPTIMUM Each species has an OPTIMUM – Temperature – pH – Air – Osmotic Pressure – Water – Nutrients

45. How can we prevent them from getting these requirements? Heat (sterilize) Heat (sterilize) Change pH Change pH Add salt or sugar Add salt or sugar Remove oxygen (canning) Remove oxygen (canning) Remove water by Dehydrating foods Remove water by Dehydrating foods

46. How do we spread diseases and how do we stop them? How do we spread diseases and how do we stop them? Five methods for spreading disease. Five methods for spreading disease. – AIR – FOOD – WATER – PERSON to PERSON – VECTORS- insects

47. How does an infection makes us sick? How does an infection makes us sick? What they do: Grow and Reproduce What they do: Grow and Reproduce – Destroys cells – Release toxins – Block passages What we do: What we do: – Crummy Article

48. Germ Theory of Disease 1857 Louis Pasteur Eliminates theory of spontaneous generation Eliminates theory of spontaneous generation Saves the wine Industry in France Saves the wine Industry in France Proposes that there is a relationship between a microorganism (pathogen) and a disease Proposes that there is a relationship between a microorganism (pathogen) and a disease Develops Develops – Pasteurization – Vaccines for anthrax and rabies

49. Koch’s Postulates 1876 Find suspect organismIsolate suspect and grow in pure culture Inject pure culture into healthy subject and get the same disease symptoms Re-isolate the same suspect organism and grow it in pure culture

50. Vaccines: Treatment for viruses Taken as a preventative method Cannot help you once you have the disease Viruses can become resistant to these, but it is not usually a fast process Human production Antibiotics: Treatment for bacterial infections Taken once you have the disease Cannot be used as a preventative Bacteria can easily become resistant to these Bacteria and some fungi produce these

51. Vaccines Involves your immune system being stimulated Involves your immune system being stimulated Dead or weakened antigen (foreign particle) Dead or weakened antigen (foreign particle) Engulfing cells and antibody producing cells destroy the antigen Engulfing cells and antibody producing cells destroy the antigen Memory cells prepare for another infection Memory cells prepare for another infection – Response to virus is faster and stronger the second time Adds to the health of the community Adds to the health of the community

52. Antibiotics Work ONLY on bacteria Work ONLY on bacteria – Bacteria are prokaryotic, we are eukaryotic – Bacteria have a cell wall, we do not. These help, but our immune system still has to “clean-up” These help, but our immune system still has to “clean-up” Examples: Examples: – Penicillin – stops cell wall formation – Tetracycline – stops protein synthesis – Ciprofloxacin – stops DNA replication

53. Proper use of antibiotics Prevents Resistance Only taking them for bacterial infections Taking pills on time Taking all your prescription

54. Concentration of Bacteria at which you feel better ===== Concentration of Bacteria at which you feel better ===== Time in Days Shot of Penicillin- Pill taking intervals – missed interval Concentration of antibiotic - Effective concentration of antibiotic --- Concentration of bacteria …… Concentration

55. Antibiotic Resistance Development of Resistance Development of Resistance – Alter the antibiotic – Alter the target or structure – Pump out the antibiotic Developing new anti-resistance antibiotics Developing new anti-resistance antibiotics – Target the mechanism that confers resistance Stop alteration of antibiotic Stop alteration of antibiotic Stop alteration of target Stop alteration of target Stop the molecular pumping mechanism Stop the molecular pumping mechanism

57. Stop the Spread of antibiotic resistance Do not demand antibiotics Take them exactly as prescribed Wash fruits and vegetables(no such thing) thoroughly; avoid raw eggs and undercooked meat, especially in ground form Use soaps and other products with antibacterial chemicals only when protecting a sick person whose defenses are weakened

58. Viroids Single-stranded RNA molecules that have no capsids Single-stranded RNA molecules that have no capsids Infect host, produces more viroids Infect host, produces more viroids Disrupts metabolism, resulting in smaller growth of plant Disrupts metabolism, resulting in smaller growth of plant

59. Prions Tiny virus-like particles like contain only proteins usually found in the brain Tiny virus-like particles like contain only proteins usually found in the brain Scrapie Scrapie Kuru Kuru Mad cow disease Mad cow disease

60. The BIG picture Diet Diet Rest Rest Exercise both aerobic and resistance Exercise both aerobic and resistance Personal Cleanliness e.g. wash your hands Personal Cleanliness e.g. wash your hands Proper Preparation and storage of food Proper Preparation and storage of food – It Must Have Been Something You Ate Environmental Cleanliness pollution, filth Environmental Cleanliness pollution, filth Annual Physical Annual Physical

61. Big Picture cont… Report symptoms promptly to a responsible person Report symptoms promptly to a responsible person Follow physicians instructions Follow physicians instructions – antibiotics Vaccinations: Vital Vaccinations: Vital – The Vaccine Conundrum