Antibiotic resistance required practical

Question 1

What is aseptic technique

Answer 1

Ensures the microbes being investigated don’t escape or become contaminated with other unwanted and possibly pathogenic microbes

Question 2

What aseptic techniques are required in investigating antibiotic resistance

Answer 2

• Washing hands thoroughly
• No food or drink in the lab
• Disinfecting work spaces with alcohol
• Not allowing the growth of microorganisms at body temperature
• wear gloves and goggles
• Flaming culture bottlenecks and spreaders to prevent contamination
• sterilising or disposing of all used equipment
• Having a lit Bunsen burner in the room because hot air rises
• Only removing petri dish lids when needed

Question 3

What apparatus is needed to investigate antibiotic resistance

Answer 3

• Sterile agar plates - sterile due to boiling
• Diluted bacterial with a concentration of CFU/mm^3
• Multiple different antibiotic solutions of a standard concentration
• Paper discs, Bunsen burner, incubator, spreader, goggles, pipettes, gloves

Question 4

What is the method to investigate antibiotic resistance

Answer 4

• Pre soak paper disks in the different antibiotic solution of same concentrations so the effects of the different antibiotics can be compared
• Spread a sample of the diluted bacterial broth onto the surface of the sterile agar plate (once the spreader and bottleneck has been flamed)
• Lightly press the paper discs onto the surface of the agar making sure they are evenly distributed
• They should not be touching the sides or other bacteria
• Keep the petri dish in an incubator overnight

Question 5

What will the results for investigating antibiotic resistance show

Answer 5

Overnight antibiotics will diffuse outwards form each paper disk so a gradient forms
- If the bacteria is vulnerable to an antibiotic a clear area will be visible around the disc
- No bacteria is present in the clear area
- More effective antibiotics require a lower concentration to kill bacteria creating a larger clear area

Question 6

What is the MIC and how can we change our investigation of antibiotic resistance to find it

Answer 6

MIC - minimum inhibitory concentration
MIC is the the lowest concentration of a substance that will inhibit the growth of a microorganism.

We would use the same antibiotic but different concentrations instead of different antibiotics of the same concentration