Transcript Lab 26-27

Lab 26-27 Goals and Objectives:
Read results
Exercise 28: Temperature Effects on Growth
Mix cultures well with pipette and transfer to cuvettes for O.D. reading
(absorbance): record data on class sheet, Record combined data
Exercise 29: pH and Microbial Growth
Mix cultures well with pipette and transfer to cuvettes for O.D. reading
(absorbance): record data on class sheet, Record combined data
Exercise 62: Temperature Lethal Effects
Score plates + or - for growth using control for comparison:
record data on class sheet, Record combined data
**Bring favorite disinfectant/antimicrobial to next lab to test!
Temp O.D.
4°C
0.03
25°C 0.51
37°C 0.72
42°C 0.63
55°C 0.14
62
TDP?
+
+
+
+
TDT
+
+
+
-
@70°C?
@80°C?
@90°C?
+
-
-
-
-
-
-
-
@100°C
?
Lab 26-27 Goals and Objectives:
**NO MADACIDE: NO HAND WASHING before 33&36!!!**
Exercise 31: Lethal Effect of UV Light
Exercise 32: Effects of Lysozyme on Bacterial Cells
Observe and record provided results
Exercise 33: Effectiveness of Alcohol as an Antiseptic
Each person do, follow supplemental packet directions p.113
Exercise 36: Effectiveness of Hand Scrubbing
Four groups total: each group elect a scrubber and scrubber assistant, Others do
plating; Use solid pre-poured plates, plate using flame
sterilized spreader, 10 plates per group:
1 tap water control (0.4ml), 3 basin A (0.1ml, 0.2ml, 0.4ml)
3 basin B (0.1ml, 0.2ml, 0.4ml), 3 basin C (0.1ml, 0.2ml, 0.4ml)
Exercise 34: Antimicrobial Sensitivity Testing
Four groups: each test all 8 antibiotics against two organisms
(assigned), two plates per organism, 4 discs per plate.
Exercise 35: Evaluation of Antiseptics
Each try five agents against both organisms S. aureus & P. aeruginosa
SAME five agents for both to compare Gram+ vs. Gram- bacteria
Exercise 31: Lethal Effect of UV Light
Do your assigned organism and times (see assignment cards)
Completely cover plate with organism: swab three times
Draw a line to indicate boundary of the card
Lid off, agar side up under lamp (unless assigned “with lid”)
Draw line on plate to
indicate boundary of card
Cover half
with paper
card
Plates agar side up, no lid,
cover half with paper card
UV Exposed side
Control
(was covered)
Exercise 32: Effects of Lysozyme on Bacterial Cells
Observe and record provided results
Exercise 33: Effectiveness of Alcohol as an Antiseptic
Supp. page 125
A
B
F
C
E
Divide plate into 6 wedges
D
A = left/non-dominant thumb dirty
B = left/non-dominant thumb again
(how many microbes removed just by touching agar?)
C = right/dominant thumb dirty
D = right/dominant thumb dipped in alcohol and allowed to dry
(how many microbes removed/killed by alcohol dip?
E = right/dominant index finger
F = right/dominant index finger wiped with alcohol swab
(how many microbes removed/killed by swabbing with alcohol?)
Exercise 36: Effectiveness of Hand Scrubbing
Fig. 36.1
Stop at step 5
while you still
have skin!
10 plates total:
1 tap water control (0.4ml),
3 basin A (0.1ml, 0.2ml, 0.4ml)
3 basin B (0.1ml, 0.2ml, 0.4ml)
3 basin C (0.1ml, 0.2ml, 0.4ml)
Exercise 34: Antimicrobial Sensitivity Testing
2 plates each organism, 4 discs per plate
Each organism gets tested against 8 different antibiotics
Group 1
Staphylococcus aureus & Escherichia coli
Group 2
Staphylococcus aureus & Proteus vulgaris
Group 3
Proteus vulgaris & Pseudomonas aeruginosa
Group 4
Escherichia coli & Pseudomonas aeruginosa
Exercise 35: Evaluation of Antiseptics
Each try five agents against both organisms:
S. aureus
P. aeruginosa
SAME five agents for both to compare Gram+ vs. Gram - bacteria