Intro to microbiology

Question 1

What are commensal microbiota?

Answer 1

microbial flora associated with the human body that can be beneficial.

Question 2

What is Koch’s Postulates?

Answer 2

criteria used to decide if a micro-organism caused a disease

Question 3

What does Koch’s postulates state?

Answer 3

Causative organism must:

• be isolated
• cultivated artificially
• typical symptoms of infection must result
• should be recoverable from individuals infected experimentaly

Question 4

What is Koch’s Postulates for genes?

Answer 4

Genes encode virulence factors.

-introduction of gene should transform strain into one that causes disease

Question 5

What are the structural components of a virus?

Answer 5

1) have a nucleic acid core
2) protein coat
3) Enveloped or naked
3) DNA or RNA

Question 6

A virus has a nucleic acid core surrounded by a protein coat. What is the protein coat made up of?

Answer 6

Protein coat is made up of units called capsomeres.

Question 7

All fungi are …

a) eukaryotic
b) prokaryotic

Answer 7

All fungi are EUKARYOTES

Question 8

What is the cell wall of fungi made of?

Answer 8

Chitin

Question 9

Moulds are fungi that grow in mats of tiny filaments. What are the filaments and mats known as?

Answer 9

Filaments = hyphae
mats = mycelia

Question 10

What is the role of septa in moulds?

Answer 10

Septa separate the mats of fungi into compartments

Question 11

What is the name of unicellular fungi?

Answer 11

yeasts

Question 12

What type of fungi is ringworm and athlete’s foot?

Answer 12

mould

Question 13

What is thrush caused by?

Answer 13

Candida Albicans

Question 14

What type of cells are protists?

a) unicellular eukaryotes
b) unicellular prokarytoes

Answer 14

Protists are unicellular eukaryotes

Question 15

What are the 4 classes of protista?

Answer 15

1) apicomplxa (formerly sporozoa)
2) flagellat protista
3) ciliate protista
4) amoebae

Question 16

Give examples of diseases caused by protists

Answer 16

1) toxoplasmosis
2) amoebic meningitis
3) malaria
4) trypanosomiasis
5) leishmaniasis
6) amoebic dysentery

Question 17

What protist can cause a foul smelling vaginal discharge?

Answer 17

Trichomonas vaginalis

Question 18

What type of cell are bacteria?

a) eukaryotes
b) prokaryotes

Answer 18

prokaryotes

Bacteria lack a membrane bound nucleus.

Question 19

What is the difference between gram positive and gram negative bacteria?

Answer 19

Gram positive:

• thick peptidoglycan wall
• stain violet / purple

Gram Negative :

• thin peptidoglycan wall
• stain red / pink

Question 20

What is the function of a capsule (in bacteria)

Answer 20

Some bacteria are enclosed within a capsule.

This helps protect the bacterium (even inside phagocytes) so helps to prevent the bacteria from being killed.

Question 21

Where do “coagulase negative” staphylococci live?

Answer 21

skin

Question 22

What are endospores?

Answer 22

endospores are produced by bacteria. They are resistant so protect against heat and radiation.

Question 23

What are the different routes of person to person infection?

Answer 23

1) airborne (inhilation of infetious droplets)
2) faecal-oral
3) sexually transmitted
4) direct inoculation
5) animals
6) objects

Question 24

What diseases are spread via faecal-oral route?

Answer 24

• Typhoid
• cholera
• dysentery
• Hepatitis A
• poliomyelitis

Question 25

What diseases are spread via animals?

Answer 25

• malaria (mosquitoes)

- salmonella enterica

Question 26

What are fomites?

Answer 26

vectors of infection that are objects such as pens

Question 27

In what diseases does an individual not need to encounter the live micro-organism but can get the disease due to exposure from the toxin?

Answer 27

1) tetanus
2) botulism
3) ergotism

Question 28

What are the mechanisms by which bacteria cause diseaseʔ

Answer 28

1) produce structure which enable them to ATTACh to the surface at which they cause disease.
2) poduce toxins
3) produce aggressins