Antibiotics

Question 1

What are antibiotics?

Answer 1

Chemical substances which damage bacterial cells without harming human tissue

Question 2

Describe the two types of antibiotic

Answer 2

Bacteriocidal = kill bacterial cells by destroying cell wall, causing lysis
Bacteriostatic = inhibit growth of bacteria by stopping synthesis of proteins + nucleic acid

Question 3

How do bacteria become resistant to antibiotics?

Answer 3

Via natural selection; bacteria not killed by antibiotic have a selective advantage; allele for antibiotic resistance is passed onto offspring creating a resistant strain

Question 4

Why are organisms and pathogens described as having an “evolutionary race”?

Answer 4

Pathogens evolve adaptations enabling survival and reproduction and evading immune system e.g. disrupting antigen presentation, making these harder for the immune system to recognise

Question 5

What can bacterial resistance lead to?

Answer 5

Antibiotic resistant bacterial infections

Question 6

Why do hospital acquired infections occur?

Answer 6

As patients in the hospital already have a weakened immune system; and antibiotics are widely used in hospitals increasing chance of resistance

Question 7

Describe measures used in hospitals to prevent hospital acquired infections

Answer 7

~ staff and visitors washing hands with alcohol-based antibacterial gels regularly
~ isolating patients who contract hospital-acquired infections to prevent spread of infection
~ disinfecting equipment after every use

Question 8

How do hospitals limit chance of antibiotic resistance?

Answer 8

• Antibiotics are only used when needed and course must be completed to ensure all bacteria are destroyed
• Rotating use of different antibiotics to lower chances of bacteria developing resistance