Today is Friday (!), January 10 th , 2014

1. In This Lesson: Unit 8 Bacteria (Lesson 1 of 2) Today is Friday (!),January 10th, 2014 Pre-Class: What does “microbiology” mean to you? How do microbes (microscopic organisms) affect us? Write down at least one thing for each question! Also, you’ll need a paper towel for your pair. Make it small!

2. Today’s Agenda • Bacteria!!! • Hey look there’s some right over there!  • Also, just to be clear: • 1 bacterium, 2 bacteria. • Where is this in my book? • P. 471 and following…

3. Challenge Questions • We always do…

4. Microbiology Questions • Throughout this lesson and the next, you’ll want to have the Microbiology Questions worksheet on your desk. • This worksheet features questions similar to those on the quiz and will cut down on the amount of notes you have to take. • I won’t, however, tell you which problems you’ll have to answer, so it’s up to you to skim the questions in case the answer to one comes up in my lessons.

5. Microbiology… • …for us is made of two sections: • Bacteria…

6. Microbiology… • …and viruses. Mmm…Ebola! http://1.bp.blogspot.com/_bjdoQjTNNNA/R09tFnD55ZI/AAAAAAAAABk/C35le2X1D6Y/s1600-R/Ebola_virus.jpg

7. But first… • How does your body fight infections? • Primarily with white blood cells, of course! • Also called leukocytes, white blood cells engulf foreign cells/viruses – basically eating them. • Phagocytosis, remember? • There are many different kinds of leukocytes. Leukocyte Unfortunate Pathogen http://imgs.sfgate.com/c/pictures/2001/04/23/mn_parasite.jpg

8. A Brief Immune System Review • To understand how white blood cells fit into the bigger picture, let’s do a brief and fast-moving overview of how your body handles invaders. • First off, technically your skin, nasal mucus, stomach acid, and lung cilia (among other structures) are considered part of your immune system. • They all act to prevent an invader from even getting inside in the first place. • But suppose something gets through the first line of defense…

9. A Brief Immune System Review • Some kind of pathogen (germ) invades the body. • The outside of this invader likely has structures on it, called antigens, that can be recognized by the immune system. • An antigen (much like the signal proteins on the outside of red blood cells) generates antibodies. • The immune response has begun. • First up, the innate (non-specific) response.

10. A Brief Immune System Review • Phagocytes, composed of neutrophils, macrophages, and dendritic cells. • The neutrophils and macrophages try to eat the invading cells. • The dendritic cells try to eat them too, but will also stimulate the next wave of immune response if necessary. • The adaptive (specific) response.

11. A Brief Immune System Review • T cells (sometimes called cytotoxic T lymphocytesor killer T cells) destroy infected cells in the body by looking for signs of pathogens on the membrane. • In addition to the normal T cells, there are also helper T cells (Th cells) that coordinate the body’s response. • They may stimulate B cells (more to come), T cells, or more phagocytes (cells that eat stuff). • In addition, natural killer cells (NK cells) look for foreign markers on the outsides of cells and destroy them.

12. A Brief Immune System Review • If stimulated by Th cells, B cells make plasma cells which in turn make antibodies, substances that can interfere with the antigens. • Meanwhile, Th cells also produce memory cells that make future similar infections easier to fight. • This is how vaccines work. • Importantly, B cells cannot invade infected body cells or cancer cells. • This job is left to T cells and their compatriots.

13. Microbes • There are more microbes (microorganisms) on your body than there are people on the entire planet. • Microbes may be responsible for producing more than half the planet’s oxygen. • One square inch of skin may have half a million microbes living on it. • There are more bacterial cells in your body than there are human cells.

14. And just how big is microbiology? • http://learn.genetics.utah.edu/content/begin/cells/scale/ • Scale of the Universe

15. Aside: Bacterial…Family Tree?

16. Aside: Bacterial…Family Tree? • “Bacteria” are divided into two evolutionary categories: • Eubacteria (or bacteria) • Archaea (or archaebacteria) • The differences are quite subtle, including: • how many subunits make up RNA polymerase enzymes • how lipids link in their membranes • pathogenicitiy (archaea aren’t pathogenic) • oxygen usage (archaea can’t have oxygen)

17. Germ Theory • So, given that these things are so small, you might imagine that biologists didn’t really pick up on them for a long time. • It wasn’t until Louis Pasteur (inventor of the Pasteurization process) came around in the late 1800s that people realized this and the Germ Theorywas developed. • Many diseases are caused by the actions of microorganisms.

18. Helpful versus Harmful • So, if you had to guess, what percentage of ALL bacteria is harmful to humans? • 1% • 99% is helpful (or at least not harmful) to us, and we’ve got plenty helping us right now in our digestive tracts. Like E. coli. • Yes, you’ve all got E. coli.

19. Helpful versus Harmful • For a look at the helpful side: • TED: Jessica Green and Karen Guillemin - You are Your Microbes

20. Helpful versus Harmful • Bacteria that are helpful can help us: • make or process foods. • digest. • create medicine. • kill pests. • balance/clean the environment. • Bacteria that are harmful can: • cause disease. • spoil food.

21. And on that topic… • A pathogen is a disease- or infection-causing agent. • Pathology is the study of pathogens and disease.

22. The 6 Big General Facts about Bacteria • They’re microscopic prokaryotes. • They’re unicellular. • They’re the most numerous organisms on Earth. • They’re the oldest form of life on Earth. • Bacterial infections are typically localized (occur at only one point in the body). • Antibiotics can be used as treatment for bacteria so long as the bacteria are not resistant. (P.S. Viruses don’t respond to antibiotics.)

23. About Resistance • Take the bacteria called staph (short for staphlyococcus). • Staph is a common form of bacteria that does no harm as long as it is on the outside of the body or in the nasal passages. • About 1 in 4 people have it without knowing it. • However, should it enter the body, it can cause a Staph infection. • Symptoms include rash, chest pains, chills, muscle aches, or more serious things like kidney failure. • Thankfully, this infection can be treated with basic antibiotics like methicillin, penicillin, or amoxicillin. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0004520/

24. But wait! • About 1 in 50 people have a form of staph that does not respond to antibiotics. It’s resistant to them. • These people actually have MRSA (pronounced “mersa”), which stands for methicillin-resistant staphylococcus aureus. • MRSA tends to pop up in hospitals, day care centers, schools, the military, or people that get tattoos. • What’s more, MRSA is becoming harder and harder to treat as the bacteria evolve to become more and more resistant to antibiotics. • MRSA is getting WRSA. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0004520/

25. Kinds of Infections • Strep throat • Staph infections • Some sinus infections • Urinary tract infections • Bacterial meningitis • Infection of the meninges (membranes covering the brain and spinal cord) that in extreme cases can lead to brain damage and/or death. • Some pneumonia • Bubonic Plague (Black Death) • Caused by bacteria in the bite of fleas carried on rodents. • Is not the subject of “Ring Around the Rosie.” • NOT BACTERIAL: • Rhinovirus • Mononucleosis • Influenza • HIV

26. Bacterial Structure • Bacteria have: • Cell Wall (#4) • Cell Membrane • Flagella (sometimes) (#1) • Ribosomes (#3) • Genetic material called a plasmid (in a nucleoid) (#2) • DNA is circular • A capsule – another membrane outside the cell wall (#5) • Pili (a.k.a. fimbrae) – to help attach to stuff – singular:pilus/fimbra

27. Bacterial Structure Review • http://www.sheppardsoftware.com/health/anatomy/cell/index.htm

28. Oxygen Usage (a reminder) • Obligate Aerobes • Must have oxygen to survive. • Obligate Anaerobes • Cannot use oxygen to survive. • Sometimes oxygen kills them. • Facultative Aerobes • Like to have oxygen, can live without it.

29. Shapes of Bacteria • Bacteria take one of three typical shapes. • (draw these in your notebooks)

30. Bacillus (Plural: Bacilli) http://commtechlab.msu.edu/sites/dlc-me/zoo/Pf07002.jpg

31. Coccus (Plural: Cocci) http://www.yellowtang.org/images/1812.jpg

32. Spirillum (Plural: Spirilla) http://biology.touchspin.com/images/spirillum.jpg

33. It’s time to play… • …IDENTIFY THAT BACTERIUM! • To win each of the five rounds, you’ll need to correctly identify the shape of the bacterium on your white board. • Your team will receive 50 imaginary bonus points for correctly identifying the actual name of the bacterium. • Some hints will be available.

34. Round One • Shape: • Coccus • Bacterium (causes): • Streptococcalpharyngitis • (strep throat)

35. Round Two • Shape: • Bacillus • Bacterium: • Escherichia coli • Commonly known as E. coli

36. Round Three • Shape: • Bacillus • Bacterium: • Bacillusanthracis • Can affect lungs, GI tract, or skin.

37. Round Four • Shape: • Spirillum • Bacterium: • Vibriocholerae • Causes cholera

38. Round Five • Shape: • Bacillus • Bacterium: • Yersinia pestis • Bubonic Plague

39. Reinforcement • Let’s try a little activity to reinforce the concept of resistance. • Lab – Antibacterial Resistance

40. Bacterial Reproduction • One healthy bacterium can reproduce into a colony of more than 2 _______ in just seven hours. • Is it… • hundred • thousand • million • billion

41. Bacterial Reproduction • Most bacteria reproduce by binary fission: • Copy the DNA ring, split in half.

42. Bacterial “Reproduction” • Some undergo conjugation: • Make a bridge between bacteria and exchange DNA/genetic material. Sex Pilus

43. Bacterial Resilience • Sometimes bacteria create an endospore: • They create a structure that helps them go dormant for an indefinite length of time to survive unfavorable conditions. • Bacteria can last several thousand years (or more?) like this. http://student.ccbcmd.edu/courses/bio141/lecguide/unit1/prostruct/images/Bmeg_spore_01.jpg

44. A word about resilience… • On April 20th, 1967, the Surveyor 3 probe sent by NASA landed on the moon. • In November of 1969, Pete Conrad from Apollo 12 visits the probe on the moon and retrieves the camera. • NASA later finds that a colony of Streptococcus mitus [from Earth] survived in the vacuum of space in the lens without nutrients! • As a result, NASA is now very careful to not contaminate other planets/moons with bacteria. • The Galileo space probe was deliberately crashed to avoid accidentally landing on Europa, a moon of Jupiter, which is suspected to have water. http://upload.wikimedia.org/wikipedia/en/7/77/Surveyor_3_on_Moon.jpg http://upload.wikimedia.org/wikipedia/commons/a/a7/Apollo12ConradSurveyor.jpg

45. Prevention and Treatment • Bacteria can be combated with antibiotics: • Drugs that interfere with their cellular functions to kill them. • Risk of antibiotic resistance, when bacteria are unaffected by antibiotics. • See video clip (14:54 or 18:03) • Or with vaccines: • Weakened or dead versions of the pathogen that helps boost immunity.

46. One last thing… • How are bacteria grown in laboratories? • In a process called culturing, bacteria (and sometimes fungi) are grown in petri dishes. • These petri dishes typically are given nutrients in the form of agar, a gelatin-like substance that can feed them. • Bacterial colonies soon become visible to the naked eye in the form of circular…splotches.

47. Bacteria Mini Research Project Picture 1—What disease(s) can your bacterium cause? 2—What type of bacterium is it? 3—What are the symptoms of the disease? 4—How it can be treated?

48. Closure Part 1 • Get started on the Microbiology Questions packet (the ones you can do so far). • You may work only with the person next to you. • No one next to you? Work alone.

49. Closure Part 2 • It’s time for our closure activity. For this, you’re going to need to get to your lab groups and research a bacterium of choice. You will create and e-mail me a PowerPoint slide showing the following: • Your names • Your bacterium • The kind of bacterium • What it does for us or to us • The treatment (if any)