History Of Microbiology Flashcards
Anton Van Leuwenhoek
Likely the first person to actually observe live microorganisms via microscopes he constructed himself. He described his findings as “animalcules” – found in samples of rainwater, his own feces, and his own tooth scrapings.
Francisco Redi
A strong opponent of SG, an Italian physician. He set out to demonstrate that maggots did not arise spontaneously. He used 2 jars of decaying meat. His experiment dealt a serious blow to the possibility that SG was real
John Needham
The case for SG was strengthened by this Englishman in 1745 when he found that even after heating nutrient fluids before pouring thee fluids into covered flasks, the cooled solutions were teeming with organisms. Needham claimed that microbes in the fluids were there due to SG.
Lazzaro Spallanzanni
An Italian scientist suggested 20 years later after Needham’s experiment that the microorganisms found in the cooled solution came from the air after his solutions were boiled.
Spallanzani showed that nutrient fluids heated after being sealed did not develop microorganisms
Rudolf Virchow
In 1858 this German scientist challenged SG with the concept of biogenesis – the claim that living cells can only arise from other
Louis Pasteur
In 1861 this French scientist resolved the issue of SG. He demonstrated that microorganisms are present in the air, and can contaminate sterile solutions, but the air itself doesn’t create the microbes.
He filled flasks with beef broth – some were left open and allowed to cool, and these flasks had microbes. The other flasks (sealed after boiling) were microorganism free.
“the golden age of microbiology.”
During the 60 years after Pasteur’s work began, there was an explosion of microbiology related discoveries, hence the period between 1857 and 1914 is named “the golden age of microbiology.” Pasteur and Robert Koch spearheaded most of these discoveries – and it resulted in microbiology being established as a science.
Major Contributions during “The Golden Age of Microbiology”
Some of the major names during this period were: Pasteur (Pasteurization), Koch (Germ theory, pure cultures, vibrio cholorae, mycobacterium tuberculosis), Petri (the Petri dish), Gram (Gram staining techniques)
Robert Hooke
Important discovery in 1665 by this Englishman “life’s smallest structural units are cells” – hence the beginning of cell theory “all living things are composed of cells”
Fermentation discovery
French Merchants asked Pasteur to find out why beer and wine spoiled – he discovered that yeasts convert the sugars to alcohol in the absence of air, a process called fermentation. Souring and spoiling were found to be due to microorganisms called bacteria – in the presence of air, bacteria change the alcohol in the beverage into acetic acid – vinegar.
The germ theory of disease
The link between yeast and fermentation led scientists to think that microorganisms could have similar relationships with plants and animals ( The germ theory of disease ) and that microorganisms may cause disease.
Edward Jenner / vaccination
On May 4, 1796 (almost 70 years before Koch discovered anthrax), a British physician named Edward Jenner gave an 8y/o girl, who had previously been infected with cow pox, another inoculation of the cowpox. After a small bump at the injection site and a mild sickness – the girl never contracted cowpox again, or smallpox which was rampant at that day and time. The process was named vaccination.
The birth of chemotherapy
After the relationship between microorganisms and disease was established, microbiologists set out to find substances that could destroy pathogenic microorganisms without damaging the infected host.
Treatment of disease via chemical substances is called chemotherapy. The success of chemotherapy is based on the fact that some chemicals are more poisonous to the microorganisms than they are to the host.
Paul Ehrlich - syphilis
Paul Ehrlich – a German physician who fired the first shot in the chemotherapy revolution. He speculated that a “silver bullet” could exist that would hunt down and destroy pathogens without harming the host. In 1910, after testing hundreds of substances, he found a chemotherapeutic agent called salvarsan, an arsenic derivative effective against syphilis.
Alexander Fleming
A Scottish physician and bacteriologist who almost tossed out a culture plate that had been contaminated with mold. Fortunately, he took a second look at the curious pattern around the mold. The mold was impeding the growth of the bacteria – the mold was later identified as penicillin chrysogenum.
