LAB 3 BACTERIAL GROWTH (3)

Question 1

Refers to the separation of a strain from a natural, mixed population of living microbes, as present in the environment. Isolation of bacteria forms a very significant step in the
diagnosis and management of the illness

Answer 1

bacterial isolation

Question 2

2 methods of isolation bacteria

Answer 2

culture methods and non-culture methods

Question 3

Laboratory technicians inoculate the sample onto certain solid agar plates
with the streak plate method or into liquid culture medium, depending what
the objective of the isolation

Answer 3

inoculation

Question 4

After the sample is inoculated into or onto the choice media, they are
incubated under the appropriate atmospheric settings

Answer 4

incubation

Question 5

1. A small amount of sample is placed on the side of the agar
   plate.
2. A sterile loop is then used to spread the bacteria out in one
   direction from the initial site of inoculation. This is done by
   moving the loop from side to side, passing through the initial site.
3. The loop is then sterilized (by flaming) again and the first
   streaks are then spread out themselves.
4. This is repeated 2-3 times, moving around the agar plat

Answer 5

STREAK PLATING METHOD

Question 6

• a chemotherapeutic agent
• designed in nature to inhibit or prevent the growth of microorganisms

Answer 6

antibiotics

Question 7

result in bacterial death

Answer 7

bactericidal agents

Question 8

cause temporary inhibition of growth

Answer 8

bacteriostatic agents

Question 9

• The ______ is also known as the DISC-DIFFUSION METHOD
• most widely used antibiotic susceptibility test in determining what treatment of antibiotics should be used when treating an infection
• relies on the inhibition of bacterial growth

Answer 9

kirby-bauer test (ANTIMICROBIAL SENSI TEST)

Question 10

Measured under STANDARD CONDITIONS. A culture medium, specific’s the __________ aseptically inoculated culture medium with the test organisms

Answer 10

mueller-hinton agar

Question 11

The size of the inoculated organism must also be standardized using barium sulfate standards ____________. because if the size is too small the zone will be larger that what it supposed to be

Answer 11

McFarland standards

Question 12

• after the plates have ben incubated, there should be a noticeable “clearing” zone around each of the antibiotics discs
• measured in MM (millimeters)

Answer 12

kirby bauer test interpretation results