Background on Bacteria Aug. 28

Background on Bacteria
I. Bacteria are the dominant species on the planet:
a. Overwhelming numerical dominance
i. Way more individuals of bacteria then all forms of life put together
ii. Become incredibly adaptive and genetically diverse because of the shorter life spans and the greatness of individual lives
- Population of organisms
- Environment that population lives in changes
- Individuals with best traits in a given environment
~When humans started using penicillin the diversity of the bacteria let the bacteria that was resistant to penicillin live and the others died. Now they are becoming more resistant to penicillin because there are only penicillin resistant bacteria left.
iii. Bacteria are more adaptable to changing environment than other kids of living things
b. Mass Dominance
i. Bacteria outweigh everything else put together
ii. Bacteria has existed way longer than any other kinds of life forms by about 2 billion years
iii. At least a few bacteria can survive virtually all environmental assaults: high temperatures, high pressures, or radiation
c. Environmental Dominance
i. Different forms of bacteria can live in any type of ecosystem, bacteria are everywhere!
~Bacteria is responsible for the air that we breathe.
ii. They shape the environment as well
d. Infectious Diseases
i. Caused by bacteria or viruses: diseases spread from person to person
ii. Symptoms from organisms growing in host
iii. They kill us better than we kill them
1. They continue to be the top killer of humans than any other cause of death
e. Normal Flora
i. Bacteria that live on and in my body
ii. Necessary for life:
1. Ecoli makes vitamin kclotting factors in blood
2. Gut bacteria digest food
3. Maintain skin health
4. Immune systemGood bacteria takes up space and when killed bad bacteria moves into where the good bacteria lived, causing you to get sick
~Semmelweis noticed that there was a connection between the people dying and the people giving birth, he introduced hand-washing between patients which wasn’t very easily accepted or used by others.
II. Spontaneous Generation
a. Life can come from non-living material
b. A sealed bottle can’t disprove spontaneous generation
c. Pastuer used a swan-necked flask and put broth in it then boiled the broth. Air can get to broth but bacteria can’t get to broth. Then he tipped the flask to get some broth caught in the neck and something starts to grow.
III. The Germ Theory of Disease
a. Previous ideas about disease causation: Humus
i. Bloodletting to help fix sickness
ii. Never tried to disprove their own thinking
b. Previous ideas about disease causation: Miasmas
i. Bad air poisons people and if bad air is removed people will get better
c. John snow figured out that the water was contaminated and that was the reasoning for the deaths.
- Discovered process to pasteurize milk
- Discovered fermentation
- More formal, safer form of vaccinations
- Discovered spores
- Worked a lot with anthrax

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