Undestanding The History Of Microbiology Flashcards
What is a microbe?
a living organism that requires a microscope to be seen
- generate the air we breathe (nitrogen gas, oxygen, and carbon dioxide)
-make essential vitamins (ie. B12)
-primary producer of the food webs
involved in food production
- some are pathogens
What are the four types of microbes?
Bacteria, Viruses, Fungi, Protozoa
What are the two types of cellular organization?
Prokaryotic - (bacteria, archaea) cell lacks a membrane - enclosed nucleus
Eukaryotic - (Plant, animal, fungi, protozoa) cells contain a membrane - bound nucleus
Viruses - non cellular microbes that must infect a host cell to reproduce
Microbes impact human culture 1
10,000 BCE - food and drinks are produced by microbial fermentation – Egyptians, Chinese, and others
Microbes impact human culture 2
15,000 BCE - tuberculosis, polio, leprosy, and smallpox are evident in mummies and tomb art – Egyptains
Microbes impact human culture 3
50 BCE - Copper is recovered from mine water and acidified by sulfur oxidizing bacteria – Roman metal workers under Julius Caesar
Microbes impact human culture 4
1,000 CE - smallpox immunization is accomplished by transfer of secreted material – Chinese and Africans
Microbes impact human culture 5
1,025 CE - Diseases are observed to be contagious. The basis of hygiene and quarantine is proposed – Avicenna, or Ibn Sina (Persia)
Microbes impact human culture 6
1,300-1,400 CE - The Black Death (bubonic plague) killed 17 million people in Europe and Asia – Catherine of Siena nursed plague victims; canonized as patron saint of nurses
Microbes impact human culture 7
!,546 CE - Syphilis and other diseases are observed tp be contagious – Girolamo Fracastoreo (Padua)
Microbial Diseases Devastate Human Population
- smallpox, tuberculosis, leprosy, bubonic plague, HIV/AIDS
- The overwhelming majority of microbes humans interact with are beneficial pr neutral
- Humans are inhabited by 10x as many bacterial cells as human cells
- Less than 1% of known bacteria causes severe and life threatening illness in humans
- History has focused on the 1% because of their impact on human life
Catherine of Siena (1347-1380)
Patron Saint of Nursing - cared for the ill and buried the dead
Early Microscopy and the Origin of Microbes dates
1676 - microbes are observed under a microscope by Antonie van Leeuwenhoek (Netherlands)
1717 - Smallpox is prevented by inoculation of pox material, a rudimentary form of immunization – African and Asia; Turkish women taught Lady Montagu who brought the practice to England
1765 - Microbes fail to grow after boiling in a sealed flask: evidence against spontaneous generation – Lazzaro Spallanzani (Padua)
1798 - Cowpox vaccination prevents smallpox – Edward Jenner (England)
1835 - Fungus causes disease in silkworms (first pathogen to be demonstrated in animals) – Agostino Bassi De Lodi (Italy)
1847 - Chlorine as antiseptic wash for doctors hands decreases pathogens – Ignaz Semmelweis (Hungary)
1881 - Bacterial spores survive boiling but are killed by cyclic boiling and cooling – John Tyndall (Ireland)
Robert Hooke
First to publish in Micrographia (1665) his work using microscope (mites, mold, small worms)
- First to observe living material and call them cells
Antoni Van Leeuwenhoek (Dutch)
First to observe and record bacteria and protozoa
- Began making and using single lens microscopes
- Often made new microscope for each specimen
-Examined water and visualized tiny animals, fungi, bacteria, algae, and single celled protozoa or small animals “animalcules” (1674)
- It took nearly 200 years before a connection was made between microbes and human diseases
Is Spontaneous Generation of Microbes possible?
Some thought living things arose from three processes
- asexual reproduction
- sexual reproduction
-nonliving matter
Aristotle
proposed spontaneous generation - living things can arise from non living matter
Experimentation - Spontaneous Generation
Redi’s experiments
- When decaying meat was kept isolated from files, maggots never developed
- Meat exposed to files was soon infested
- As a result, scientist began to doubt Aristotle’s theory
Needham’s Experiments - Spontaneous Generation
Broth (gravy) is boiled in flask
- One flask is left open
- One flask is sealed with corks
- Both flasks were cloudy (turbid)
- Scientist thought microbes, but not animals, could arise spontaneously
- Needham’s experiments reinforced this idea
- Vials were cloudy due to a “life force”
Spallanzani’s Experiments - Spontaneous Generation
- Both (gravy) is boiled in flask for an hour
- One flask is left open
- One flask is completely sealed
- Flask did not become cloudy unless seal was broken
Pastur’s Experiments - Spontaneous Generation
When the “swan-necked” flask remained upright, no microbial growth appeared
- When the flask was titled, dust from the bend in the neck seeped back into the flask and made the infusion cloudy with microbes within a day
The Scientific Method
- Spontanoue generation debate led in part to scientic method
- Observation leads to question
- Question generates hypothesis
- Hypothesis is tested through experiment(s)
- Results prove or disprove hypothesis — accepted hypothesis leads to theory/law - Reject or modify hypothesis
What causes Fermentation?
• spoiled wine threatened livelihood of vintners
• some believed air caused fermentation; others insisted living organisms caused fermentation
• vintners funded research of methods to promote
production of alcohol and prevent spoilage during fermentation
• this debate also linked to debate over spontaneous
generation
What causes Disease?
Divine Origin of Disease
- A lor of the early historry of microbiolgy was under the unfleunce of scoial and theological beliefs of the times
- Among ancient people, epidemics of disease were thought to be supernatural in origin , sent bt the Gods as punishment for the sins of man. Treatment and prevention were by sacrifices to appease the anger of the gods
- Gradually the Divine Origin of Disease was rejected, as the belief in “living agents” as the case of the disease grew slowly. Some refer to this belief in living agents as the “Germ Theory of Disease”