History of Microbiology (Chapter 1)

Question 1

What is Microbiology?

Answer 1

The study of microorganisms (or microbe) ‐ organisms that mostly cannot be seen by the naked eye

Question 2

organisms that mostly cannot be seen by the naked eye are called:

Answer 2

microscopic

Question 3

Microorganisms may exist as single cells are called:

Answer 3

unicellular

Question 4

2 conditions to be viewed as a microorganism

Answer 4

They must be able to generate energy and grow without the help of other cells.

Question 5

Microbes that form
communities and that are able
to “talk” to each other to initiate
group behaviour are called:

Answer 5

biofilms

Question 6

Where can we find microorganisms? 3 examples

Answer 6

tongue
teeth plaque
screens

Question 7

When were microorganism first studied and what invention allowed this?

Answer 7

The science of microbiology did not exist before the invention of microscopes at the beginning of the 17c. (logical – can’t study microbes without knowing they exist!)

Question 8

who am I ? English mathematician and historian that described the microscopic appearance of dry cork as a honeycomb of chambers that he named cellulae (hence “cell”). He also published the first accurate microscopic drawings of a variety of molds.
And in what year?

Answer 8

In 1665, Robert Hooke

Question 9

microscopic structures are also called:

Answer 9

Sporangia

Question 10

1) Who am I? Father of microbiology that published the first drawing of what he called “wee animalcules.”
2) What is particular important to know about these wee animalcules?
3) And in what year?

Answer 10

Antoni van Leeuwenhoek
This was the first time microorganisms were seen!
In 1684

Question 11

What is a major cause of mortality and morbidity throughout history

Answer 11

Infectious diseases

Question 12

the true cause of infectious diseases was not known before which century:

Answer 12

19th

Question 13

Domains that have been influenced by infectious diseases: 5

Answer 13

politics, economy, religion, science and literature.

Question 14

What infectious disease killed 30‐60% of the European population at the end of the 14c? Which bacteria caused this?

Answer 14

An outbreak of black death (plague)

caused by a bacterium called Yersinia pestis

Question 15

Which infectious disease led to the potato famine in Ireland and more than a million people died of starvation in the 1840s? Which bacteria caused this?

Answer 15

A fungal disease of potatoes (blight)

caused by a mold called Phytophtora infestans

Question 16

Poor medical knowledge prior to the 19c led to: 2 things and give an example for each

Answer 16

• Inaccurate theories to explain the causes/outbreaks of diseases, such as the miasma theory.
  – Use of inappropriate treatments, for example bleeding, which causes more damage.

Question 17

What is the miasma theory?

Answer 17

The miasma theory is an obsolete medical theory that held that diseases—such as cholera, chlamydia, or the Black Death—were caused by a miasma, a noxious form of “bad air”, also known as night air. The theory held that the origin of epidemics was due to a miasma, emanating from rotting organic matter

Question 18

What lead physicians to wonder that infectious disease were not due to spontaneous generation?

Answer 18

17c: Some physicians started to wonder, could disease be due to something tangible? (invisible organisms?) – contagion (19c) = transmission between people… this theory not in agreement with spontaneous generation!

Question 19

What is the spontaneous generation theory?

Answer 19

Hypothesis that some vital force can create living organisms from inanimate objects. It was widely accepted throughout the middle ages and into the latter half of the 19c, because it fitted nicely with the religious views of most people.

Question 20

Who am I? I demonstrated that maggots did not develop from meat protected by a fine gauze cover (showed that contact with the outside is required!) =>flies cannot reach the meat and lay their eggs = need contact with outside

Answer 20

Francesco Redi => mid 1600

Question 21

Who am I? I demonstrated that nothing grew in liquids that were boiled and stored in closed containers. The proponents of spontaneous generation argued that a free supply of air was required for the “vital force” to reach the liquid.

Answer 21

Late 1700s: Lazzaro Spallanzani

Question 22

Experiment that serves as evidence against spontaneous generation:

Answer 22

Louis Pasteur’s classic experiment (1861)

Question 23

What was Louis Pasteur’s classic experiment (1861) about?

Answer 23

Louis Pasteur designed an experiment to test whether sterile nutrient broth could spontaneously generate microbial life. To do this, he set up two experiments. In both, Pasteur added nutrient broth to flasks, bent the necks of the flasks into S shapes, and then boiled the broth to kill any existing microbes.
After the broth had been sterilized, Pasteur broke off the swan necks from the flasks in Experiment 1, exposing the nutrient broth within them to air from above. The flasks in Experiment 2 were left alone.
Over time, dust particles from the air fell into the broken flasks of Experiment 1. In Experiment 2, dust particles remained near the tip of the swan necks, but could not travel against gravity into the flasks, keeping the nutrient broth sterile.
The broth in the broken flasks quickly became cloudy–a sign that it teemed with microbial life. However, the broth in the unbroken flasks remained clear. Without the introduction of dust–on which microbes can travel–no life arose. Thus, the Louis Pasteur experiment refuted the notion of spontaneous generation.

Question 24

Germ theory?

Answer 24

recognition that some diseases are caused by microorganisms, and preventing exposure prevents the disease. BASED ON OBSERVATIONS…

Question 25

Germ theory => Puerperal sepsis ?

Answer 25

genital tract sepsis caused by contaminated equipment or unhygienic medical staff.

Question 26

Who am I? I observed that the women attended by medical students during childbirth were at greater risk of contracting this disease, than those attended by midwives. (related to the Puerperal sepsis)

Answer 26

Ignaz Semelweis (1847)

Question 27

“cadaveric principles” were solved by who (1) using what chemical agent (2) and how does this principle work (3)?

Answer 27

1) Ignaz Semelweis (1847)

2) Hand washing in chlorine solution solved the problem 3) Because it killed bacteria

Question 28

Germ theory=> Who am I? I reported that death due to infection following surgery could be reduced dramatically if diluted phenol was used to soak the medical devices and surgical dressings and to spray the general area during surgery.

Answer 28

1867: Joseph Lister

Question 29

Germ theory=> Who am I? published that anthrax was caused by a bacterium. He also showed that tuberculosis, causing one‐seventh of all human deaths at the time, was caused by an another bacterium.

Answer 29

1884: Robert Koch

Question 30

What was the name of the bacterium causing tuberculosis? Anthrax?

Answer 30

Mycobacterium tuberculosis

Bacillus anthracis

Question 31

link to be made between germ theory and Pasteur’s experiment:

Answer 31

Pasteur’s experiment had already shown that microorganisms were present in the air, revealing a possible source of infection.

Question 32

Advancement du to Pasteurs experiments: 2

Answer 32

– Led to development of effective sterilization procedures and pasteurization.
– Pasteur also developed vaccines for multiple diseases, such as anthrax, fowl cholera and rabies.

Question 33

How to prove that a microbe causes disease?

Answer 33

Koch’s postulates
The Postulates:
1. The suspected pathogen
must be present in all cases of the disease and absent from healthy animals.
2. The suspected pathogen must be grown in pure culture.
3. Cells from a pure culture of the suspected pathogen must cause disease in a healthy animal.
4. The suspected pathogen must be reisolated and shown to be the same as the original.
Tools:
1)Microscopy, staining
2Laboratory culture
3)Experimental animals
4)Laboratory reisolation and culture
(see diagram)

Question 34

True or false? Only a very small percentage of the bacterial species on Earth are able to cause disease in humans.

Answer 34

True

Question 35

Name 2 types of microbials and explain the difference

Answer 35

Bacteria
Archaea: microorganisms which are similar to bacteria in size and simplicity of structure but radically different in molecular organization. They are now believed to constitute an ancient group which is intermediate between the bacteria and eukaryotes.
*Both are Prokaryotes “before the nucleus”

Question 36

Name 5 eucaryotes and give examples

Answer 36

– Protozoa (ex: Amoeba)
– Alga (ex: Euglena)
– Fungi (ex: yeasts)
– Plant cells
– Animal cells

Question 37

name 3 other types of microbials (not pro/eucaryotes)

Answer 37

Viruses, Viroids, Prion

Question 38

Microorganisms are diverse because

Answer 38

they have had a very long time to evolve and differentiate

Question 39

Infectious diseases examples: 3

Answer 39

tuberculosi
lepersis
strep throat by streptococcus
(look at pictures)

Question 40

What OTHER roles do microbes play in our lives?

4

Answer 40

Agriculture
Food Industry
Chemical and Pharmaceutical Industry
Environment

Question 41

What element is essential for life in agriculture?

Answer 41

Nitrogen is essential for life: amino acids, nucleotides and other cellular constituent (must be biologically available, ex. NH3)

Question 42

How do some bacterial species use nitrogen?

Answer 42

Some bacterial species can form nodules on the roots of some plant species. They convert atmospheric nitrogen (N2) to ammonia (NH3) that the plant can use as a source of nitrogen for growth.

Question 43

Why can cows digest grass?

Answer 43

Cellulose is digested using the enzyme cellulase, which cows do not produce. But bacteria do! (symbiosis)
grass=>cellulose=>glucose=>microbial fermentation=> FA (nutrition for animals) & CO2+CH4 (waste products)

Question 44

Chemical and Pharmaceutical Industry

Microorganisms are used to produce:

Answer 44

organic acids (citric acid), alcohols, vitamins, antibiotics.

Question 45

Chemical and Pharmaceutical Industry
Microorganisms can be genetically modified to produce :
How?

Answer 45

a useful product such as insulin, human growth hormones, etc.
because: bacteria easily take up exogenous genetic material ‐ natural evolutionary mechanism

Question 46

Chemical and Pharmaceutical Industry

Name 2 biofuels

Answer 46

methane/ethanol

Question 47

Role of microorganisms in the environment: 2

Answer 47

Important role in recycling nutrients such as carbon, nitrogen and sulfur.
Some organisms can metabolize (detoxify) toxic compounds = bioremediation of contaminated soil/sediment.