1. Bacteria: the good, the bad and the ugly
Anne Todgham and Annick Gauthier
University of British Columbia

2. What are bacteria? Rod-like Bacteria
Small organisms - several µm (1/1000 of a cm, can only see 1/100)
They have all they need to live
DNA
Energy
Food
Can make proteins
Good and bad bacteria!!!!!!
Bacteria can be killed with antibiotics
Viruses are different - need host to “live”
Can’t kill virus with antibiotics
Rod-like Bacteria

3. Pictures of Bacteria
Anthrax
Bacteria from Fish
Anabena

4. Where are bacteria? On our skin In our intestinal tract
Help us digest food
In our mouth, throat
In the soil
In the ocean
In the forest
On plants
Everywhere!

5. Good vs Bad Some bacteria cause disease meningitis pneumoniae diarrhea
Good bacteria too: for example E. coli
there are disease-causing strains
there are digestion-helping strains

6. Why we should love bacteria
Live happily in the guts and lungs of animals
aid in digestion of food and vitamin production
stimulate the growth of some of our tissues
Fight foreign disease causing bacteria and prevent them from infecting us
Important in the cycling of nutrients in the environment ex. nitrogen and carbon
Make up the bottom of most food webs
critical for the survival of most living organisms
thought to be the origin of multicellular organisms

7. We are a great home to live in!!
Why bacteria love us
Our bodies provide bacteria with:
Constant supply of nutrients
Stable environment and constant temperature
Protection
Transportation
We are a great home to live in!!

8. Interesting tidbits
1013 bacteria in/on human body, and only 1012 human cells
109 bacteria per gram of feces (population of world)
Only a very small number of “bad” bacteria
We breathe in 3-4 bacteria per breath
Number one infection: cavities
50% of worlds population dies of infectious diseases (20% in our society)
Infectious diseases are the leading cause for taking time off of work
More people died in the Civil War of infectious disease that by bullets.

9. More cool bacteria numbers
Oldest fossil known is bacteria-like organisms that are 3.5 billion years old!!
bacteria in each cm2 of skin
1 billion bacteria in a teaspoon of soil
80 distinguishable species of bacteria living in the mouth alone
Greater than 200 species of bacteria living on the entire body
Can reproduce every 20 min

10. Uses for Bacteria
Production of antibiotics like streptomycin and nocardicin
Put the tang in yogurt and the sour in sour cream
Vaccination (dead or weak bugs used to boost our immune system)
Can be used to break down oil after an oil spill

11. Growing Bacteria
All the bacteria that we will grow are normal bacteria that do not cause disease
Bacteria grow in colonies on a substance called agar that contains sugars and salts
We have poured these agar plates for you
CONDUCT EXPERIMENT
Incubate plates at 37oC at UBC for 2 days
Plates will be stored in fridge until October 23 when we will return to discuss results with you

12. Materials and Methods
Objective: to culture bacteria from around the classroom and your body
Materials: 1 LB agar plate, 4 cotton swabs, pencil and paper to take notes, marker
Method:
1. Using black marker, divide plate into 4 quadrants, label plate with your name and the date in small letters
2. Choose which 4 areas you will swab and record this in your science duotang
3. Label the plate with the areas you will swab
note label the bottom (i.e. agar containing part of the plate)
4. Remove one sterile swab from its packaging (do not touch it), swab area of choice by gently rubbing cotton swab on it, and then transferring this to the LB agar plate by gently rubbing the agar in the designated quadrant
5. Repeat step 4 for 3 other areas of choice
6. Clean up: put LB plate and marker into middle of your table, put all cotton swabs and wrappers into orange garbage bag

13. Pictorial of Procedure
Next class:

14. Growing Bacteria thumb mouth, nose or ear floor table phone keyboard
light switch
sink
sink faucet
toilet handle
toilet

15. Culturing Bacteria

17. Identification of Bacteria
Grow bacteria on different media
Different bacteria grow on different types of plates
Check for antibiotic resistance
Jessica’s expt
Use stains or antibodies
Gram stain
Antibodies “agglutinate”
Clump up bacteria
DNA
amplify certain genes

18. How do we defend ourselves?
Non-specific
Skin
Hair
Shedding cells
Tears
Macrophages
Good bacteria!
Specific
Antibodies
B cells
T cells

19. Picture of Gastrointestinal Tract

20. Bacteria of the mouth
Dental plaque, cavities and periodontal disease result from the actions initiated by our normal bacterial flora
60-70% of the volume of plaque is made of bacteria -- these bacteria release lactic acid that breaks down the enamel of the teeth and can cause cavities and further infection of your mouth

21. Picture of Respiratory System

22. Life without bacteria
Normal bacterial flora are very important in protecting our bodies from pathogenic or disease-causing bacteria
Administration of broad-spectrum antibiotics has a profound effect on our “good” bacteria and can result in “bad” antibiotic-resistant bacteria infecting our bodies
Animals raised in an environment filled with bacteria are much healthier than those raised in a sterile environment
Clean hypothesis
People need bacteria to live

23. How can we stay healthy? Good nutrition Low stress Age Cleanliness
but we need bacteria
antibacterial soaps
Regular doctor and dental visits
Vaccines up to date