PHCY219 – Microbiology Section 1 – Lecture 1 Judith Bateman
Lecture 1 - Microbiology in our World
First terms test will have two questions from each lecture
It will cover lectures 1 - 15
It is worth 15%
30 MCQs in total to answer in 50 minutes
1. Describe the major microbiological discoveries in history
Need to remember the year, the scientist and the discovery!!!
1664 - Robert Hook: Observation of mould under a crude microscope
1684 - Antoni van Leeuwenhoek: Observation of further detail
1822-1895 - Louis Pasteur: Pasteur Flask
Dust and microbes can settle in the S-bend of the flask
but the angle of the glass means that it can’t enter the
body of the flask and contaminate the liquid in there.
Note: Even though the flask was sterilised, dust and
microbes were still able to settle in the S-bend of the
flask (open top). By tipping the flask, the microbes were
carried back into the body of the flask. In the presence
of moisture, these microbes grew. The microbes that
contaminated the sample came from the air.
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2. Discuss ‘spontaneous generation’
This was a theory that perhaps life was generated spontaneously. This issue was addressed when Louis Pasteur.
Evidence from the experiment pictured above DID NOT SUPPORT THE THEORY OF SPONTANEOUS GENERATION
Evidence --> theory of spontaneous generation not viable
Lead to pasteurisation
3. discuss Koch’s postulates
1843-1910 - Robert Koch - Koch's postulates
How can disease spread between individuals? This question was addressed by Robert Koch. Four parts to know!
Tuberculosis – killed many people in 1881 (around 1/7 deaths caused by TB). Animal model that was used was
guinea pig. TB has a waxy coat so difficult for immune system to pick it up.
Note: Not all organisms today can be grown in a plate.
Jospeh Lister Aspetic techniques, sterilisation of
instruments and environment in surgery better
survival rates. Germ theory.
1918-1919 - Influenza epidemic killed 20 million
4 processes that reduce infectious disease death
1. Chlorinated water
2. Pasteurised milk
3. Increased antibiotic use
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4. Improved sewage
1928 - Fleming: Discovery of Penicillin (yellow excretion in the picture)
Discovery was serendipitous. Many plates were cultured with different organisms however there was an incidence in
particular where there was a no growth zone (bacteria couldn’t colonise in that area). It was due to fungi Penicillium
notatum. Yellow excretion is anti-biotic.
Organisms that produce antibiotics