Antimicrobial Therapy - Tutorial 4

Question 1

Define selective toxicity

Answer 1

The ability to kill the microbe but not harm the patient

Question 2

Define the terms bactericidal & bacteriostatic

Answer 2

Bactericidal: directly kill the bacteria

Bacteriostatic: inhibit growth of the bacteria that then enables the body’s defence mechanisms to remove the bacteria

Question 3

Describe the difference between broad spectrum and narrow spectrum antibiotics, and explain the advantages & disadvantages of each

Answer 3

• Broad spectrum - kill a wide range of Gram-positive & Gram-negative bacteria but also destroy normal flora and increases AB resistance But has an immediate start
• Narrow spectrum - effective against a select group of pathogens. Kills fewer normal flora and decreases AB resistance, disadvantage organism is not killed if wrong AB and takes longer to identify

Question 4

Explain the term antibiotic resistance & give one example of an infection that is resistant

Answer 4

It is the acquired ability of a microbe to resist the effects of an antimicrobial agent to which it is normal susceptible, example; MRSA (methicillin-resistant Staphylococcus aureus)

Question 5

Describe three ways to reduce antibiotic resistance

Answer 5

• Avoid excessive prescribing of antimicrobials
• Finish the full course of antibiotics to discourage the survival and proliferation of resistant strains
• Never use left-over antibiotics or antibiotics that are prescribed for someone else
• Avoid forming aerosols when drawing up antibiotics

Question 6

List four ways antimicrobials work

Answer 6

• interferes with cell wall synthesis
• interfere with DNA replication
• interfere with protein synthesis
• interrupt metabolic reactions inside the cell