Antibiotics resistance and misuse

Question 1

What are antibiotics?

Answer 1

Chemicals used to kill bacteria

Produced by bacteria or fungi

Not bacterisins

In low concentration used by bacteria in communication

Question 2

What role does Darwins theory of evolution play in resistance?

Answer 2

Most pragmatic example of survival of the fittest

As use of antibiotics increases, so does resistance as stonger selection pressure exerted

Question 3

Process of resistance

Answer 3

1. Accumulation of resistant bacteria
2. Mutant selection
3. Spread of resistance via HGT
4. Spread of resistant strains

Question 4

What two types of selection pressures act on bacterial population?

Answer 4

Those that act on DNA level

Those that act on how the bacteria is spread

Question 5

Examples of selection pressures that act on a DNA scale

Answer 5

Antibiotic use
Environmental antibiotic exposure
Exposure to heavy metals
Other factors like age and class

Question 6

Examples of selection pressure that act on how bacteria is spread

Answer 6

Crowding
Travel
Poor hygiene
Animals

Question 7

Mechanisms of resistance that bacteria use

Answer 7

1. Efflux pump
2. Antibiotic degradation and alteration
3. Change gene expression of target proteins

Question 8

How does the bacteria cause antibiotic degradation or alteration?

Answer 8

Gene produces protein that detoxifies the antibiotic via cleaving or conjugating

Question 9

How does the efflux pump make the bacteria resitant?

Answer 9

Protein is encoded by gene that inserts itself into the membrane

This protein exports antibiotics from the inside of the cell to the outside

Decreases the intracellular concentration of the antibiotic

Question 10

What are the two types of resistance the bacteria can acquire?

Answer 10

Intrinsic

Acquired

Question 11

What is intrinsic resistance?

Answer 11

Naturally occuring trait of an organism

Species or genus specific

Question 12

Examples of intrinsic resistance

Answer 12

Impermeable to the antibiotic

No receptor for the antibiotic to bind

Question 13

How does changing the gene expression of targeted proteins confer resistance?

Answer 13

As antibodies only target one specific protein, changing its expression will render the antibiotic useless

The protein may change shape

The protein may be overproduced so the antibiotic becomes oversaturated

Question 14

What are amalgam restorations

Answer 14

Fillings put on your teeth

Made of copper, tin, silver and mercury

Question 15

Do bacteria gain resistance to amalgam restorations?

Answer 15

Yes, via genes on mobile genetic elements to other resistances

Question 16

How are the resistance genes transferred between bacteria?

Answer 16

1. Transformation
2. Transduction
3. Conjugation

Question 17

What does transformation entail?

Answer 17

Transfer of free DNA from dead host and living recipient

when bacterial cells die and lyse, they release their contents into the environment

Their DNA is taken up by competent cells

DNA is incorporated into their genome and resistance will be expressed

Question 18

What does conjugation entail?

Answer 18

Between live donor and recipient

ATP dependent mechanism whereby there is a tranfer of plasmid or conjugative transposon containing the resistance gene

Question 19

What is a conjugative transposon?

Answer 19

Transposons are small pieces of DNA that insert themselves into another locus on a genome

Question 20

What does transduction entail?

Answer 20

Uses bacteriophages

VIral delivery system whereby phages invade bacteria and cause them to lyse.

During their replication, phages have inserted genome from the bacteria into phage particles

When the bacteria lyse and release these phages, they are now free to invade other cells and integrates the genome containing the resistant gene into the new hosts

Question 21

What are nanotubes?

Answer 21

Way in which bacteria become interconnected and transmit information through channels built between them

Pilli-like structures

Speculations

Question 22

What is the feature of developing a solution for antibiotic resistance?

Answer 22

Bury bacteria in soil to look for natural antibiotics

Stewardship

Question 23

How was Teixobactin discovered?

Answer 23

Bury bacteria underground to see if there are natural antibodies in the soil that can combat them

Teixobactin is a soil antibiotic against gram positive bacteria

Question 24

What is Stewardship?

Answer 24

Doctors have to be careful when prescribing pills

40% of GPs admit to feeling pressured to prescribe antibiotics

30% admit to falling under pressure and giving antibiotics

Question 25

How is antibiotic use in the present day?

Answer 25

By 200 days of life, 70% of infants have been subjected to antibiotics

By age 8, 97% of children have been subjected to antibiotics