1. Is spontaneous generation of microbial life possible?
2. What causes fermentation?
3. What causes disease?
4. How can we prevent infection and disease? 

·         Is spontaneous generation of microbial life possible?

o   No:

§  Redi: demonstrated that maggots appear on decaying meat only when flies were able to lay eggs.

§  Pasteur: demonstrated that microorganisms are in the air using the swan-necked flasks. Dust settled in the bottom of the neck.

·   Lead to antiseptic techniques in laboratories to prevent contamination from microbes in air.

§  Virchow: 

·         What causes fermentation?

o   Yeast ferments sugars to alcohol and bacteria can oxidize the alcohol to acetic acid. 

·         What causes disease?

o   Microorganisms:

§  Bassi/Pasture showed relationships

§  Koch: proved that microorganisms cause disease.

·         Koch Postulates:

1. MO or pathogens must be present in all cases of the disease
2.  pathogen can be isolated from the diseased host and grown in pure culture
3.  pathogen from the pure culture must cause the disease when inoculated into a healthy, susceptible laboratory animal
4. pathogen must be reisolated from the new host and shown to be the same as the originally inoculated pathogen

·         How can we prevent infection and disease?

o   Disinfectant:

§  Lister: introduced disinfectant to clean surgical dressings (Phenol)

 o   Vaccination:

§  Conferred by inoculation with a vaccine

·         Jenner: demonstrated with cowpox material providing immunity from smallpox

·         Pasture: discovered that avirulent bacteria could be used as a vaccine for fowl cholera, coined the word “vaccine”

• each cell contains a nucleus surrounded by a membrane.
• can see with the naked eye

• lack a nuclei, genes are not surrounded by a membrane
• cannot be seen by the naked eye

Fungi

• Eukaryotic
• true nucleus
• multicellular
• obtain nutrients by absorbing organic material from environment

Protozoa

• Eukaryotic
• Unicellular
• Obtain nutrients by absorbing or ingesting through specialized structures

Algae

• Eukaryotic
• Unicellular / multicellular
• Photosynthetic organism
• Found in fresh water

• Prokaryotes
• unicellular
• reproduce asexually

Viruses 

• Non-cellular
• Parasites of cells
• Nucleic acid core (DNA or RNA) surrounded by a protein coat (prion)

• First discovered bacterial world
• Discoverer of protozoa
• Leeuwenhoek took the construction of a superior micro scope to his grave

• Invented taxonomy system

·         First to demonstrate doubt in Aristotle’s Spontaneous generation theory

·         Demonstrated that maggots appear on decaying meat only when flies were able to lay eggs.

• Studied fermentation
• Sugar to alcohol, alcohol + bacteria = acidic acid
• Discovered yeast is facultative anaerobes (can live with or without oxygen)
• Invented pasteurization
• Started industrial microbiology (biotechnology)
• Proved pathogens cause infectious disease (germ theory of disease)
• Swan-neck flask experiment
• Developed successful vaccines for cholera, anthrax, rabies

• Proved pathogens cause infectious disease (germ theory of disease)
• Koch’s Postulates: logical steps to follow to prove the cause on infectious disease
• First photomicrograph of bacteria

• Invented the gram stain procedure: differentiate bacteria into 2 categories
• Gram-positive
• Gram-negative

• Added in foundation of infection control and epidemiology
• Discovered the relation between hand washing and reduced morality rates

• Added in foundation of infection control and epidemiology
• Founder of antiseptic surgery
• Used phenol on wounds, incisions, and dressings to reduce death and infection

• Added in foundation of infection control and epidemiology
• Introduced cleanliness and other antiseptic techniques into nursing practices

• foundation of infection control and epidemiology

Founding epidemiology by relating cholera to public watering systems

• Cowpox based vaccine preventing smallpox
• Began immunology

• Searched for magic bullet (chemicals that kill microorganisms but not human cells)
• Founded chemotherapy