4.1.1.6 Culturing Microorganisms (biology only)

Question 1

What are uncontaminated cultures of microorganisms needed for?

Answer 1

uncontaminated cultures of microorganisms are required for investigating the action of disinfectants and antibiotics

Question 2

How and when do bacteria multiply?

Answer 2

if bacteria have a supply of nutrients and a suitable temperature, bacteria can multiply quickly by binary fission as fast as every 20 mins

Question 3

What are the two ways to grow microorganisms e.g. bacteria in the lab?

Answer 3

1. In nutrient broth solution
2. On an agar gel plate

Question 4

Drug:

Answer 4

any chemical that alters how the body works

Question 5

Who was penicillin discovered by?

Answer 5

Alexander Fleming

Question 6

MRSA:

Answer 6

• any strain of Staphylococcus bacteria that is resistance to antibiotics
• superbug - high levels of resistance

Question 7

What family of bacteria does MRSA belong to?

Answer 7

Staphylococcus

Question 8

Where did MRSA come from?

Answer 8

• MRSA evolved because of natural selection
• there are lots of different strains of the bacteria
• each strain has slightly different DNA
• the DNA is constantly mutating as the bacteria reproduce
• some of these mutations are more resistant to antibiotics than others
• when people take antibiotics, the less resistant strain die first and the more resistant strains are harder to destroy
• if people do not finish their course of antibiotics, the more resistant strain survive and reproduce to pass on their DNA
• in this way, more strains evolve to be resistant to antibiotics

Question 9

Why is MRSA a problem in hospitals?

Answer 9

• Risk of people dying from MRSA higher in hospitals due to:
  
  • patients already weak, making them more likely to become infected
  • MRSA easily passed on when doctors and nurses touch different patients

Question 10

How can MRSA be treated?

Answer 10

• patients need very high doses of antibiotics to make sure all bacteria are destroyed
• new antibiotics can also be used until the bacteria gain resistance

Question 11

Ways hospitals can prevent the spread of MRSA among their patients:

Answer 11

• maintain personal hygiene - doctors wash/sanitise hands before and after interacting with each patient
• carefully clean hospital rooms and medical equipment
• isolate MRSA infected patients