1. Antibiotic Resistant Bacteria: Natural Selection at Work

2. Bacteria are everywhere
Bacteria are single-celled organisms
Many different kinds of bacteria can grow together in similar environments
Millions of different bacteria live on and inside of you!
Pictures taken with an electron microscope

3. Serratia marcescens Grow in damp places
Bathrooms
Soil
Biofilm on teeth
Digestive tract
As a human pathogen, can be associated with urinary tract and wound infections
What’s a pathogen?

4. What are antibiotics? Powerful medicines that treat
bacterial infections
- Do NOT work on viruses!
WHY?
Think “Anti-Bio”… Kills living things…
Are viruses alive?
Antibiotics kill bacteria

5. How do bacteria become resistant?
A mutation in the DNA of the bacteria makes it resistant the harmful effects of the antibiotic
So, it cannot be killed by the medicine
If the bacteria is not destroyed… What will it do?????
Genes for resistance can appear spontaneously (genetic mutation)
This can happen with insects as well!
Bacteria can prevent ab from entering cells by making strong cell wall or making a false receptor in the membrane or they can make an enzyme that breaks down the ab within the cell

6. Natural Antibiotic Resistance
Mutations that allow bacteria to resist the effects of antibiotics already exist in the bacterial population
Not all bacterial cells within a population are identical
Like a population of humans, they
all contain slight differences in their
DNA (variation)
Why do you think this may be a good
idea for the bacteria?
-Survival of the Fittest

7. Can the misuse of antibiotics result in resistant bacteria?
Antibiotics are prescribed by doctors to fight bacterial infections
Antibiotics do not treat viral infections!
How do doctors know what to prescribe?
throat, urine cultures
Why is it important to finish your prescription?

8. Tuberculosis
TB affects your lungs and coughing is often the only sign of infection until it’s too late
Yes… you can die from TB
In the US, TB declined in the 1950s mainly because of antibiotics
TB is re-emerging
World Health Organization indicates that rates of tuberculosis resistant to multiple drugs (MDR-TB) are now at their highest level ever
Mycobacterium tuberculosis
TB lung infection

9. What are some potential problems because of antibiotic resistant bacteria?
MRSA
What is MRSA
The Truth about Methicillin-resistant Staphylococcus aureus

10. Good Bacteria? YES!
Our bodies provide a home for many kinds of good (and necessary) bacteria!
In our gut
In our mouth
On our skin
Bacteria in the mouth
Pimple caused by bacteria

11. How can we prevent bacterial growth?
We try to prevent the growth of some bacteria on our bodies and in our homes
What are some common products you use on a regular basis for cleaning?
Soaps (hand soap, face wash)
Toothpaste/mouthwash
Dish soap
Laundry detergent
Mops and sponges
Most if not all contain a chemical to prevent bacterial growth

12. 99.9%....
Antibacterial soaps, hand sanitizers, household cleaners and Listerine state that they kill 99.9% of bacteria
What about the remaining 0.1%?
Remember… If you survive… you feed and breed?
What does that mean??
The 0.1% of bacteria that are not affected by the cleaners will reproduce…
Creating an entire generation of bacteria which are resistant to sanitizers!

13. Are we causing the evolution of resistant bacteria with the use of antibacterial products?
Long term exposure to chemicals allows the bacteria that contain genes for resistance to survive and reproduce at a rapid rate!
What do you think?
Should antibacterial products be used in such a common way?

14. The Same Happens With Insects

16. Remember… VARIATION (diversity) ensures that a species will survive…
Remember “Contagion”!
The MORE VARIATIONS in a species (ANY species… from humans to daffodils to amoebas to mosquitoes to dalmations…) the greater the chance of survival!
More genetic diversity ensures the species will continue to exist!