Transport Mechanisms

Question 1

Antimicrobial resistance

Answer 1

• can directly contribute to deaths
• overuse of antibiotics was reported during early treatment of COVID-19
• spread of AMR linked to travel of people and livestock
• shown by whole genome sequence to define the human population of C.difficile
• spread of AMR exacerbated by differences in hygiene standards

Question 2

Methods of reducing AMR

Answer 2

• reduced use of antibiotics via stewardship programmes
• development and use of new diagnostic tools
• increase understanding of AMR

Question 2

Antibiotic resistance mechanisms

Answer 2

2 main methods for bacteria to withstand the effects of an antibiotic:
1. to bypass or modify the target that the antibiotic acts on
2. to stop the antibiotic from reaching its target at a high enough concentration

Question 3

Multi-drug transporters

Answer 3

• important in antibiotic resistance
• MDTs are polyspecific and present at tissue-fluid barriers

Question 4

Multi-drug transporter families

Answer 4

ABC = ATP-binding cassette
MFS = major facilitator superfamily
MATE = multiple antibiotic and toxin extension family
SMR = small multidrug resistance family
RND = resistance, nodulation and cell division family

ABCs are primary active whilst all others are secondary active, via antiport with protons

Question 5

Trans-bilayer transport

Answer 5

• TMA-DPH is a model compound for antibiotics
• partitioning of TMA-DPH in the membrane occurs with fast and slow kinetics
  1) fast = partitioning in outer leaflet of membrane
  2) slow = flipping of the inner leaflet