Medical Microbiology The History. What is Microbiology? It is the study of microbes or...
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Transcript of Medical Microbiology The History. What is Microbiology? It is the study of microbes or...
Medical MicrobiologyThe History
What is Microbiology? It is the study of microbes or
microorganisms
Microbes, or microorganisms are minute living things that are usually unable to be viewed with the naked eye.
What is Microbiology continued
What are some examples of microbes?
Bacteria, fungi, protozoa, algae, viruses, and some are parasites (helminths)
Some are pathogenic
Microbiology also involves processes that include immunology, epidemiology, bacterial physiology
History of Microbiology First microbes were observed in 1673
Robert Hooke- In 1665 reported that living things were composed of little boxes or cells devised the compound microscope and
illumination system
Antoni van Leeuwenhoek- (1673-1723) He is considered the father of bacteriology
Made simple microscopes and began observing with them
Discovered bacteria (he called them animalcules)
Leeuwenhoek's microscope consisted simply of:
A) a screw for adjusting the height of the object being examined
B) a metal plate serving as the body C) a skewer to impale the object and
rotate it D) the lens itself, which was spherical
History of Microbiology Many believed in spontaneous generation:
Aristotle synthesized the hypothesis which stated that some vital force contained in given to organic matter can create living organisms from inanimate objects.
In basic terms spontaneous generation stated that living organisms arise from non living matter.
History of Microbiology Spontaneous generation was disproved
in 1668 by Italian Scientist, Francesco Redi.
History of Microbiology John Needham- revived the theory of
spontaneous generation in 1745
Needham theorized that if he took chicken broth and heated it, all living things in it would die.
After heating some broth, he let a flask cool and sit at a constant temperature. The development of a thick turbid solution of microorganisms in the flask was strong proof to Needham of the existence of spontaneous generation.
Lazzaro Spallanzani (1729-1799) He demonstrated that microorganisms were
already in the solution, the container, or the air
He took solutions which he knew would "breed" organisms and boiled them for up to an hour. The flasks were hermetically sealed to keep out contaminated air.
History of Microbiology Theory of biogenesis later arose
In 1858 German scientist, Rudolf Virchow challenged spontaneous generation with his concept of biogenesis Living organisms arise from pre-existing life
Virchow presented his idea to the scientific community, but could not back it up with a convincing experiment
History of Microbiology In 1861, a French scientist by the name
of Louis Pasteur demonstrated where microorganisms came from
Father of Medical Microbiology
Demonstrated the microorganisms exist in the air and could contaminate sterile solutions by passing air through cotton filters
The filter trapped tiny particles floating in the air
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History of Microbiology
Louis Pasteur performed numerous experiments to discover why wine and dairy products became sour
He found that bacteria were to blame
Pasteur called attention to the importance of microorganisms in everyday life and stirred scientists to think that if bacteria could make the wine “sick,” then perhaps they could cause human illness.
Louis Pasteur’s Swan neck flask experiment
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Golden Age of Microbiology1857- 1914
Beginning with Pasteur’s work, discoveries included the relationship between microbes and disease, immunity and antimicrobial medicine
Germ theory of disease
Pasteur showed that microbes are responsible for fermentation
Microbial growth is also responsible for spoilage of food
Pasteur demonstrated that spoilage bacteria could be killed with heat (pasteurization)
Developed vaccines for anthrax (1881)and rabies (1885)
Germ theory disease 1835: Agostino Bassi- showed a
silkworm diseases was caused by a fungus
1865: Pasteur- believed that another silkworm disease was caused by a protozoan
1840s: Ignaz Semmelwise- advocated hand washing to prevent transmission of fever from one OB patient to another
Germ theory disease 1860s: Joseph Lister- He is the father of
antiseptic surgery. He used a chemical disinfectant (carbolic acid)
to prevent surgical wound infections after Pasteur’s work showing microbes are in the air, can spoil food, and cause animal disease.
1867: Robert Koch- provided proof that bacterium causes anthrax and provided the experimental steps, Koch’s postulates, used to prove that a specific microbe causes a specific disease.
Koch’s postulates Pathogen must be present in all cases of
disease Pathogen must be isolated and grown in
lab in pure culture Pathogen from pure cultures must cause
disease when inoculated into healthy, susceptible lab animal
Same pathogen must be isolated from the diseased lab animal
History of Vaccination
A precursor of smallpox vaccination was variolation
An early Asian method which introduced dried scabs of smallpox patients and was later modified in Europe
Modification consisted of injecting infectious material under the skin
First tested among abandoned children and prisoners
When it was declared safe, members of the English royal family were inoculated
Vaccination continued: 1796: Edward Jenner is credited with the
development of the smallpox vaccine
Folk wisdom suggested that dairy maids who had contracted cowpox seemed to be immune to smallpox
Infection with the cowpox virus produced a much less sever form of disease that smallpox
Vaccination continued Jenner conducted an
experiment in which he used scabs from the cowpox lesions on the arm of a dairy maid, Sarah Nelmes to create a small pox vaccine
He then used the material to vaccinate an 8 year old boy, James Phipps
After being vaccinated Phipps appeared to develop immunity to the smallpox virus.
Vaccination continued Later Jenner vaccinated his own son and
several other children
He obtained similar results
Worldwide elimination of smallpox was achieved in 1978
Called vaccination from vacca for cow
The protection is called immunity
Antibiotics 1928: Alexander Fleming
discovered the first antibiotic.
He observed that Penicillium fungus made an antibiotic, penicillin, that killed S. aureus.
1940s: Penicillin was tested clinically and mass produced and was available towards the end of World War II
Development of Agar Angelina Hesse developed the use of
Agar to grow microorganisms. She was the wife of Walter Hesse who
worked in Koch’s laboratory Advantages of agar- It was not attacked
by most bacteria. Agar is better than gelatin because of its
higher melting point (96°c) and solidifying (40–45°c) points.
Petri Dish Richard Petri (1887)
He developed the Petri dish (plate), a container used for solid culture media