Antimicrobials

Question 1

How are antibiotics mostly cleared from the body?

Answer 1

by the bacteria themselves

Question 2

what is the breakpoint?

Answer 2

the concentration at which bacteria are susceptible to successful treatment by an antibiotic

Question 3

When is a bacteria classed as resistant in regard to the breakpoint?

Answer 3

if the antibiotic needs to be at a higher concentration than the breakpoint to treat the infection

Question 4

What classes an infection as multi-drug resistant?

Answer 4

the bacteria are resistant to at least 3 of the major classes of antibiotics

Question 5

What classes an infection as extensively-drug resistant?

Answer 5

the bacteria are resistant to at least 5 of the major classes of antibiotics

Question 6

What classes an infection as pan-drug resistant?

Answer 6

the bacteria are resistant to all known classes of antibiotics

Question 7

What does antibiotic resistance mean in the lab?

Answer 7

when the minimum inhibitory concentration of a drug against a bacteria is greater than the breakpoint

Question 8

What does antibiotic resistance mean in the patient?

Answer 8

when the minimum inhibitory concentration of a drug against the bacteria is not achieved for long enough to cure the infection

Question 9

What are four factors that can affect the minimum inhibitory concentration (and therefore the level of antibiotic resistance) in a patient?

Answer 9

dose size/dose frequency, the pharmacokinetics of the drug in the patient, the infection site, the pharmacodynamics of the drugs against the infecting bacteria

Question 10

What is the definition of antibiotic resistance?

Answer 10

the failure of an antibiotic to kill or arrest a bacterial population

Question 11

What theory do antibiotics work on?

Answer 11

the lock and key theory

Question 12

In general, how does antibiotic resistance occur?

Answer 12

resistance methods stop the antibiotic-target site complex developing

Question 13

What are efflux pumps?

Answer 13

systems in the bacteria that pump out waste products and toxic substances from inside the cell

Question 14

How are efflux pumps regulated?

Answer 14

DNA

Question 15

What are the two outcomes of a natural, spontaneous DNA mutation?

Answer 15

they can be silent mutations or have an affect on how the cell functions

Question 16

What is the consequence of the bacteria developing resistance?

Answer 16

the cell will need to reroute energy from elsewhere

Question 17

What can happen to bacteria that become resistant to Colistin?

Answer 17

they take longer to grow and divide and can eventually be outcompeted for resources

Question 18

What is the gene that codes for the metallo-beta-lactamase enzyme?

Answer 18

NDM-1

Question 19

What does the metallo-beta-lactamase enzyme do?

Answer 19

‘chops up’ beta-lactam antibiotics and renders them inert

Question 20

Where is the NDM-1 gene carried?

Answer 20

on plasmids

Question 21

Which class of antibiotics are the most widely prescribed?

Answer 21

beta-lactamase

Question 22

How can plasmids be spread between bacteria?

Answer 22

conjugation

Question 23

What is the consequence of the bacteria gaining a plasmid?

Answer 23

it needs to use energy to carry and express those genes meaning the ability of the bacteria to cause infection is significantly impacted

Question 24

Is a bacteria always a problem if it is highly resistant?

Answer 24

no, if the bacteria cannot spread infection it isn’t clinically relevant

Question 25

Are antbiotics mostly natural or synthetic?

Answer 25

natural

Question 26

Which class of antibiotics are entirely chemically synthesized?

Answer 26

quinolones

Question 27

What are the four mechanisms of antibiotic resistance?

Answer 27

target site modification, replacement of antibiotic target by non-susceptible target, reduced permeability/efflux pumps, enzymatic degradation/modification of the drug

Question 28

Is reduced permeability/efflux pumps more of a problem in gram +ve or gram -ve bacteria?

Answer 28

gram -ve due to their outer membrane

Question 29

Are antibiotics lipid or water soluble?

Answer 29

water soluble

Question 30

What is the normal method antibiotics use to enter a cell?

Answer 30

they hijack a pore

Question 31

How can bacteria prevent the antibiotics entering the cell?

Answer 31

reducing the size/number of pores

Question 32

How can you reverse the effect of reduced permeability?

Answer 32

improve the penetration of the antibiotics

Question 33

How can some bacterial enzymes affect antibiotics?

Answer 33

some actively breakdown the antibiotic, others modify the drug

Question 34

Can plasmids carry more than one resistance gene?

Answer 34

yes

Question 35

Does your chance of gaining a resistant strain of bacteria increase or decrease after a course of antibiotics?

Answer 35

increase

Question 36

How long does it take for your chance of gaining a resistant strain of bacteria go back to baseline after a course of antibiotics?

Answer 36

a year

Question 37

How does a course of antibiotics make you more susceptible to a resistant strain?

Answer 37

the antibiotics kill bacteria creating a vacuum where another species fill the gap, this species may carry the resistance gene

Question 38

What are some ways we can combat antibiotic resistance?

Answer 38

smart surfaces, inhibition of resistance, improve failed antibiotics, find new antibiotics, improve existing antibiotics, rapid AMR detection

Question 39

How can smart surfaces reduce resistance?

Answer 39

a 'spiky' silica surface can kill the bacteria before they infect by acting as a physical barrier, this removes the need for antibiotics and reduces the chance of resistance developing

Question 40

How can inhibition of resistance reduce antibiotic resistance?

Answer 40

blocking the bacterial methods of resistance chemically, by giving another substance in conjunction with the drug such as to block the enzymes that breakdown antibiotics

Question 41

How can improving failed antibiotics reduce antibiotic resistance?

Answer 41

improve penetration to combat reduced permeability, conjugate the antibiotics with iron molecules that will get taken into the bacteria and bring the antibiotic with it

Question 42

What is the bacterial iron molecule that you can conjugate with an antibiotic in order to combat reduced permeability

Answer 42

siderophore

Question 43

What is an antibiotic that you can conjugate with a bacterial iron molecule to combat reduced permeability?

Answer 43

Cefiderocol

Question 44

How can finding new antibiotics reduce antibiotic resistance?

Answer 44

no common circulating resistance genes yet

Question 45

What are some ways being used to try and find new antibiotics?

Answer 45

finding the compounds in toad skin or making chemically from fungi

Question 46

How can improving exisiting antibiotics reduce resistance?

Answer 46

there may be a strain of the current antibiotic that is better at killing bacteria

Question 47

What are the ways you can try to improve exisiting antibiotics?

Answer 47

modify each gene to see if the end chemical is better at killing bacteria

Question 48

What is rapid AMR detection?

Answer 48

rapid antimicrobial resistance detection, is a machine that can determine which antibiotics the bacteria are resistant to before you give the treatment to the patient

Question 49

How can rapid AMR detection reduce antibiotic resistance?

Answer 49

it allows you to determine which antibiotics will actually work and allows the use of effective narrow spectrum antibiotics