Bacteria As Causes Of Diseases - 21.11.23

Question 1

Define pathogen

Answer 1

Organism that causes or is capable of causing disease

Question 2

Define commensal

Answer 2

Organism which colonises the host but causes no disease in normal circumstances

Question 3

Define opportunist pathogen

Answer 3

Microbe that only causes disease if host defences are compromised

Question 4

Define virulence/pathogenicity

Answer 4

The degree to which a given organism is pathogenic

Question 5

Define asymptomatic carriage

Answer 5

When a pathogen is carried harmlessly at a tissue site where it causes no disease

Question 6

How does bacteria nomenclature work?

Answer 6

Staphylococcus (genus) aureus (species)

Question 7

Gram positive stain what colour?

Answer 7

Purple

Question 8

Gram negative stain what colour?

Answer 8

Pink

Question 9

Structure of bacteria

Answer 9

Slide 22/23

Question 10

What are the rod like structures on bacteria? (Can have these)

Answer 10

Pili/fimbriae

Question 11

What is the structure of a gram positive bacteria?

Answer 11

See slide 28

Question 12

What is the structure of a gram negative bacteria?

Answer 12

See slide 28

Question 13

In what temperature conditions can bacteria survive?

Answer 13

-80 degrees to 80 degrees (120 degrees for spores)

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Question 14

In what pH conditions can bacteria survive?

Answer 14

4-9

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Question 15

In what water/desiccation conditions can bacteria survive?

Answer 15

2 hrs to 3 months (>50 years for spores)

Question 16

In what light conditions can bacteria survive?

Answer 16

UV

Question 17

Bacterial toxins can be endotoxin or exotoxin. True or false?

Answer 17

True

Question 18

Define endotoxin bacteria?

Answer 18

Component of the outer membrane of bacteria, eg lipopolysaccharide in Gram negative bacteria

Question 19

Define exotoxin bacteria

Answer 19

Secreted proteins of Gram positive and Gram negative bacteria

Question 20

Can plasmids be transferred from one bacteria to another?

Answer 20

YES

Question 21

Structure of plasmid

Answer 21

Slide 44

Question 22

What are the 3 methods of mutations of bacteria

Answer 22

Base substitution
Deletion
Insertion

Question 23

What are the 3 methods of gene transfer of bacteria

Answer 23

Transformation eg via plasmid
Transduction eg via phage
Conjugation eg via sex pilus

Question 24

Do bacteria have nuclei????

Answer 24

No

Question 25

What are the 3 types of obligate intracellular bacteria?

Answer 25

Rickettsia
Chlamydia
Coxiella

Question 26

What is the name of bacteria that may be cultured on artificial media with no cell wall?

Answer 26

Mollicutes

Question 27

What are the groups of bacteria that may be cultured on artificial media, with a cell wall and growing as single cells?

Answer 27

Rods
Cocci
Spirochaetes

Question 28

What are the 3 bacteria in spirochaetes

Answer 28

Leptospira
Treponema
Borrelia

Question 29

What are the gram negative bacteria in cocci which are anaerobic

Answer 29

Veillonella

Question 30

What are the gram negative bacteria in cocci which are aerobic

Answer 30

N. meningitis
N. gonorrhoeae

Question 31

What are the 3 groups within streptococcus?

Answer 31

Beta-haemolytic
Alpha-haemolytic
Non-haemolytic

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