1.1. History and Scope of Microbiology Flashcards
1.1 A Why Study Microbiology? 1.1B The History and Development of Microbiology 1.1C What is the Scope of Microbiology? 1.1D The Impact of Microbiology on Society
Why did people start studying microbiology?
People first began studying microbiology because of its effects on human health. In ancient times, people had very limited knowledge about the existence of microorganisms and how they could cause diseases. As a result, infectious diseases spread rapidly through populations, leading to high mortality rates.
What is a zoonotic bacterium?
A bacterium that may be transmitted from animals to humans
Zoonotic bacteria responsible for the Black Death or Bubonic Plague
Yersinia pestis
How did the Bubonic Plague become a “plague”?
Yersinia pestis were found on fleas that cling onto rat fur which were then transported via boats to cities that were highly populated, killing 75-200 million people
A thermophilic bacterium isolated from hot springs in Yellowstone National Park used to produce an enzyme called Taq polymerase
Thermus aquaticus
What is a Taq polymerase?
A DNA polymerase that can withstand the high temperatures required during PCR, which makes it ideal for amplifying DNA sequences.
How is Taq polymerase obtained from Thermus aquaticus?
Thermus aquaticus is isolated > cultured > cell lysis wherein cells are lysed to release its content including Taq polymerase > enzyme is isolated
The most dominant life form on Earth; accounts for 60% of the planet’s biomass
Microbes
How do microorganisms critically influence life?
- Activity and evolution
- Symbioses
- Pathogenicity
Activity and evolution
~ 4 billion years ago, there was no free oxygen at all; the Earth used to be anoxic. However, 2.46 billion years ago, cyanobacteria oxygenated the Earth, contributing to the evolution of complex life.
Symbioses
Ruminants like cows form symbiotic relationships with bacteria that produce cellulase. Cows can digest the cellulose in grass, and the bacteria are provided with shelter in the cows’ rumen.
Pathogenicity
Microbes can be pathogenic and produce illnesses. Diarrheal disease is the 2nd leading disease that kills children under 5 years old.
Microbiology can be applied in many fields.
Microorganisms have major impacts on the world we interact with; hence, microbiology has myriad applications.
What is Microbiology?
Study of organisms that are too small to be seen by the naked eye, what they are, how they work, and what they do.
What invention gave rise to the study of Microbiology?
Microscope
The first known description of microorganisms was made by ____ in his book ____ illustrating many microscopic images using a ____ microscope; this includes the fruiting structure of ____.
Robert Hooke
Micrographia
compound microscope
molds
The first person to see bacteria in ___ using a hand lens (___ microscope); He wrote to Royal Society of London who made an English translation of his work.
Antoni van Leeuwenhoek
pepper water
simple
A pioneer of protistology who developed microscopes to observe “animalcules”; rival of Leeuwenhoek; ridiculed for his “imaginative” portrayal of microscopic protists
Louis Joblot
What is Spontaneous Generation?
An archaic theory proposing that life forms can spontaneously arise from non-living matter due to a “vital essence” in oxygen
The progress of microbiology was slow due to the belief of spontaneous generation. True or False?
True
Francesco Redi
Set up an experiment with three jars containing pieces of meat: one left open, one with a cork, and one with a gauze. Flies laid eggs in the first, did not in the second, and laid eggs on the gauze in the third. Flies are simply attracted to rotten meat; they do not arise from it.
Ignaz Semmelweis
The maternity ward run by doctors who also operated on cadavers saw an 80% mortality rate, whereas the ward run by midwives saw only a 20% mortality rate. When a colleague died soon after dissecting a cadaver with a cut on his hand, Semmelweis realized something in the cadavers must be causing illness. After ordering doctors to wash their hands with chlorine before attending to patients, the mortality rate decreased to 20%.
John Snow
During a cholera outbreak (Vibrio cholerae) in London, Snow mapped out the concentrations of sick individuals and found they were highly concentrated around a particular well. After interviewing people, he found a mother had been disposing of her infant’s diarrhea in a cesspit near the well — both of which apparently had holes that connected them to one another.
The only building in the immediate vicinity that was not affected by the outbreak was the bar, not because patrons drank alcohol, but because the water used to make the alcohol was boiled, killing the bacteria.
Louis Pasteur
Disproved Spontaneous Generation using swan neck flasks filled with liquid broth. Dust and microorganisms from air remained trapped in the bend in the flask, and the liquid did not putrefy. But when the liquid was allowed to touch the dusty portion of the flask, it did not take long for it to spoil.
Joseph Lister
Worked on bone fractures and realized that infections could arise where there were exposed wounds, so he used gaseous carbolic acid (a strong phenol) to sterilize both the room and the area around the patient.
Set of criteria that establishes whether a certain organism is the cause of a particular disease.
The Koch Postulates
The Koch Postulates
- The suspected pathogen must be present in all cases of the disease and
absent from healthy animals. - The disease organism must be isolated in pure culture.
- Inoculation of a sample of the culture into a healthy, susceptible animal must
produce the same disease. - The disease organism must be recovered from the newly inoculated animal.
Who made the Koch Postulates?
Robert Hermann Koch
Alexander Fleming
Noticed a zone of inhibition around a mold in a culture of Staphylococci and extracted penicillin from the fungus Penicillium notatum, which became the most widely used antibiotic (helped along by WW2’s need for medicine)
Two Types of Microbiology
Basic Research Microbiology
Applied Microbiology
