Introduction to Microbiology

Question 1

Name a ‘superbug’

Answer 1

MRSA

Question 2

What does streptococcus pyogenes do?

Answer 2

Necrotising bacteria

Eats flesh

Question 3

What does the term ‘microorganism’ encompase?

Answer 3

Bacteria
Viruses
Fungi: yeasts, moulds
Parasites and algae

Question 4

Who is the founder of the field of bacteriology?

Answer 4

Ferdinand Cohn

Question 5

Who are the two fathers of microbiology?

Answer 5

Louis Pasteur

Robert Koch

Question 6

What did Louis Pasteur do?

Answer 6

He disproved the idea of spontaneous generation

Question 7

How did Louis Pasteur disprove spontaneous generation?

5

Answer 7

He got two sterile flasks filled with a medium

One was placed upright the other on its side

Bacteria couldn’t get by the bend in the neck of the upright flask and couldn’t colonise the medium

Bacteria could reach the medium in the medium in the neck of the sideways flask

This refuted the idea that cells can arise spontaneously from nonliving matter

Question 8

Other than disprove spontaneous generation what did Pasteur do?
(3)

Answer 8

He proposed that if food were treated so as to destroy all living organisms and protected from further contamination, it would not putrefy

This led to the development of effective sterilisation such as ‘pasteurisation’

He also developed vaccines for anthrax and rabies

Question 9

What two diseases did Pasteur make vaccines for?

Answer 9

Anthrax

Rabies

Question 10

On what basis did Pasteur make his vaccines?

Answer 10

His notion that a ‘weak form’ of an infection might cause immunity to the virulent form

Question 11

What was Robert Koch’s main contribution to microbiology?

2

Answer 11

The Germ Theory of Disease

and therefore Koch’s Postulates

Question 12

What are Koch’s postulates?

Answer 12

A sequence of experimental steps to relate a specific microbe to a specific disease

Question 13

How did Koch prove his germ theory of disease?

2

Answer 13

When working with bacteria that causes anthrax he showed that a small amount of blood from a diseased animal could transfer the disease to a previously healthy mouse

He also found that the bacteria could be grown outside of the mouse and still caused disease when re-inoculated into another mouse

Question 14

What are the four steps to Koch’s postulates?

4

Answer 14

The suspected pathogenic organism should be present in all cases of the disease and absent from healthy animals

The suspected organism should be grown in pure culture

Cells from a pure culture of the suspected organism should cause disease in a healthy animal

The organism should be re-isolated and shown to be the same as the original

Question 15

List Koch’s main contributions to microbiology.

5

Answer 15

Discovered the cause of tuberculosis, Mycobacterium tuberculosis

Developed methods for bacterial staining

Improved methods for bacterial growth (Agar plates)

Created pure cultures and began to characterise bacteria

Improved bacterial purification techniques and urged the sterilisation of surgical instruments with heat

Question 16

What bacteria did Koch discover?

Answer 16

Mycobacterium tuberculosis

Question 17

Why did it take us until the 1930s to expand work on viruses?

Answer 17

As this was when the electron microscope was invented

Question 18

What major work was done in 1929?

Answer 18

Alexander Fleming discovered penicllin

Question 19

Give five areas in life where microorganisms play a major role.

Answer 19

Health

Agriculture

food

Environment

Biotechnology

Question 20

What name is given to microbes with a protect role to man?

Answer 20

Microbiome

Question 21

What name is given to microbes that cause infectious disease?

Answer 21

Pathogens

Question 22

How do we control infectious diseases?

3

Answer 22

Understanding the disease processes of different pathogens

Improved sanitary and infection control practices

Discovery of antimicrobial agents and vaccines

Question 23

How do microorganisms remain major threats to health?

5

Answer 23

New pathogens are always emerging e.g. Ebola and Covid-19

Current pathogenic organisms continue to cause serious infection

Increasing numbers of immuno-compromised patients susceptible to infection

Many pathogenic organisms resistant to action of antimicrobial therapy

Increasing amount of life-saving invasive procedures

Question 24

What four categories of products are made by microorganisms?

Answer 24

Foods

Alcoholic beverages

Chemicals

Antibiotics

Question 25

How do microorganisms play a role in energy production?

Answer 25

Natural gas (methane) is a product of bacterial activity

Question 26

What is bioremediation?

Answer 26

The use of microbes to clean up toxic spills

Question 27

Explain the relationship between microorganisms and biotechnology.

Answer 27

Biotech involve the use of microorganisms in industrial biosynthesis, typically by organisms that have been genetically modified to synthesize products of high commercial value

E.g. production of human insulin

Question 28

How are microorganisms used in genetics?

2

Answer 28

Used in genetic engineering as tools for the artificial manipulation of genes in cells

Used in gene therapy whereby an absent or faulty gene is replaced by a working gene

Question 29

Give a use of gene therapy.

Answer 29

Used to treat sickle cell anaemia and cystic fibrosis