Growth Inhibition of epidermidis and Escherichia coli Using Various Anti-microbial Agents.

Domonique Jackson, Janecia Wilson, Railene Echevarria, Kijhauna Stevens Introduction

S. epidermidis – • Investigations: • Gram positive • Found on the skin 1. Listerine on S. epidermidis and E. coli E. coli • Found in the intestines, bad 2. Environmental Microbes when found in the blood • Gram negative 1. What agents can inhibit the growth of – used on living things S.epidermidis and E. coli? Detergent – used on fomites – products of living 2. What Antibiotics work on things (mold) yourself? Purpose

1. To determine if Listerine will inhibit the growth of S. epidermidis and E. coli

2. To analyze if bacterial growth on fomites

3. To determine which cleaning agents work better on bacteria

4. To determine the effectiveness of antibiotics on human natural flora Materials & Methods

Part 1: 1. Add 5 mL of Tryptic Soy Broth (TSB) into test tube marked control. 2. Add 5 mL of Listerine into another test tube. 3. Add 5 mL of stock of Staph into each of the two test tubes 4. After 1 minute, add 100 μL from the test tube containing Listerine and Staph into a flask containing 100 mL of TSB marked 1 minute. 5. After 5 minutes, add 100 μL from the test tube containing Listerine and Staph into another flask containing 100 mL of TSB marked 5 minutes. 6. Place 100 μL from control test tube into the flask containing 100 mL of TSB marked control. 7. Set the spectrophotometer to 550 nm and place the TSB blank in the machine to set to 0 absorbance. 8. Take 100 μL from control flask and place in a cuvette 9. Place into spectrophotometer and take absorbance reading 10. Repeat steps 7-9 for the 1 minute and 5 minute flasks 11. After recording the absorbance of all three flasks, place them in an incubator at 37°C for 48 hours total taking periodic measurements in the same fashion as described above. 12. Repeat steps 1-11 for E. coli. Part 2: 1. Dip a sterile cotton swab in water and swab a large area of the surface being tested (i.e. elevator button). 2. Then, wipe cotton swab all over a Tryptic Soy Agar (TSA) plate and cover. 3. Repeat for each designated place, then incubate the plates at 37 degrees Celsius for 24 hours. Materials & Methods

Part 3: 1. Swab each plate with a sterile cotton swab (as described in Part 4) containing stock solution of Staph or E-coli 2. Draw a line down the middle of plates 3. Get 8 disks and dip one in a corresponding cleaning agent 4. Place two disks, containing the cleaning agents, on each plate according to their number designation 5. Place all the plates in the incubator at 37°C or 98.6°F for 24 hours 6. Measure the diameter of the zones of inhibition after 24 hours Part 4: 1. Swab the area behind your ear using a cotton swab. Incubate on a TSA plate at 37 degrees Celsius. Recolonize after 24 hrs the bacteria onto 2 plates onto two TSA plates using the previous TSA plate. 2. Place the 6 disks containing 6 different antibiotics onto the plates (3 on each) 3. Incubate the plates for 24 hrs at 37 degrees Celsius 4. Then, the zones of inhibition were measured and compared against a table of data to determine resistivity, and intermediate effect, or sensitivity to each of the antibiotics 1.8 1.8

1.6 1.6

1.4 1.4 ) 1.2 m 1.2 n 0

5 1 1 5 Control

( Control

s 0.8 0.8 t 1 Minute 1 Minute n 5 Minute e 5 Minute 0.6 b 0.6 r o bsorbents (550nm) ss

0.4 AA 0.4 b A

0.2 0.2

0 0 0 1000 2000 3000 0 1000 2000 3000 -0.2 -0.2 Time (Minutes) Time (Minutes)

Figure 1: Inhibition of Growth using Listerine on Staph (left graph) and E. coli (right graph) 60 50 40 Staphepidermidis 30 E.coli 20 10

Zones Of inhibition (mm) inhibition Of Zones 0 o l x x e e o l p e s o le in id h a e t y o r i r x o o l L l T te o lc S p h s r A n m C L i P e o g a w C n in D l g e b ia o u b D r R y d H Cleaning Products

Figure 2: Inhibition of Growth using Different Cleaning Products Figure 3: Zone of Inhibition of Dawn (7) and Dial Complete Antibacterial Soap (8) Figure 4: Environmental Microbes Figure 5: Environmental Microbes Table 1: Zones Of Inhibition

Resistant Intermediate Sensitive

Ampicillin CD, LB, JW, KS, - >29 mm DJ, RE <28 mm Bacitracin CD, LB, JW, KS, 9-12 mm >13 mm DJ, RE <8 mm Chloramphenicol <17 mm RE 18-20 mm CD, LB, JW, KS, DJ >21 mm RE <12 mm JW 13-16 mm CD, LB, KS, DJ >17mm CD, LB, JW, KS, - >29 mm DJ, RE <28 mm Tetracycline CD, JW <18 mm DJ, RE 19-22 mm LB, KS >23 mm Conclusions

• Listerine may have had an effect on slowing the growth of E. coli and S. epidermidis • Anti-microbial agents differed in effectiveness based on gram positive versus gram negative • Be aware of what products used on which types of bacteria • Bacteria can be beneficial depending on location • All were resistant to and penicillin because they were same family Conclusions

• Sources of Error: • Contamination • Pipetting incorrectly

• Further Experiments: • Different volumes • Different cleaning agents, i.e. Natural cleaning products