Transcript No Slide Title

• Many people in hospitals die every year
from catheter infections.
• A catheter is a perfect breeding ground for
infectious bacteria because the immune
system cannot reach it to defend the body.
• Through all the handling, it is almost
impossible to prevent the contamination.
• Catheter: a flexible tube inserted into the body for medical uses
such as injection or withdrawal of fluids
• Ampicillin: this drug has been proved to terminate hazardous
germs
• DTAB: surfactant with a positive charge (cationic)
• Surfactant: a surface active agent
• Lysozyme: commercially available protein that exhibits
antimicrobial activity at an interface
• Nisin: an antimicrobial protein that inhibits the growth of Grampositive cells and spores
• SDS: a surfactant with a negative charge (anionic)
• We created two concentrations
of DTAB, Beta Lactoglobulin,
Lysozyme, SDS, Nisin.
• We cut pieces of catheter tubing
and then dipped them in the
different concentrations of our
antibiotics. We held them in the
antibiotic for 60 seconds and
then rinsed them in sodium
phosphate.
• Next we placed them in one of
two bioassay plates containing
either pediococcus or e-coli.
•
We inserted our plates in the
incubator to give the bacteria a
chance to grow and be killed. We
knew if an antibacterial agent had
worked if there was kill zone.
• The kill zone is an area that is
discolored or is a circle with no
living bacteria present.
• We noted how our control
substances, Ampicillin and water,
did as predicted. The Ampicillin
was the positive control and the
water the negative.
• A bioassay plate is a petri
dish that often holds agar
to grow bacteria. In our
project, we used e-coli
and pediococcus in the
agar to see what would
kill bacteria. This would
be indicated by a clearer
area in the agar.
• We were trying to coat the
catheter with an
antibacterial agent to fend
off bacteria that could be
harmful. This would
prevent infections in
people when they have a
catheter.
Antibiotics
DTAB
Beta Lactoglobulin
Lysozyme
SDS
Nisin
Low er Concentration Higher Concentration
.31 mg/ml
.1 mg/ml
.11 mg/ml
.285 mg/ml
.1 mg/ml
31 mg/ml
1 mg/ml
1 mg/ml
28.5 mg/ml
1 mg/ml
Antibiotics
Concentration (mg/ml)
DTAB
0.31
DTAB
31.00
Beta Lactoglobulin
0.10
Beta Lactoglobulin
1.00
Lysozyme
0.11
Lysozyme
1.00
SDS
0.29
SDS
28.50
Nisin
0.10
Nisin
1.00
Ampicillin
1.00
Water
Kill Zone (mm)
none
11
none
none
8
none
none
1
3
4
13
none
Antibiotics
Concentration (mg/ml)
DTAB
0.31
DTAB
31.00
Beta Lactoglobulin
0.10
Beta Lactoglobulin
1.00
Lysozyme
0.11
Lysozyme
1.00
SDS
0.29
SDS
28.50
Nisin
0.10
Nisin
1.00
Ampicillin
1.00
Water
Kill Zone (mm)
none
8
none
none
none
none
none
none
none
none
4.5 mm
none
Since different bacteria have different types of
cell walls, certain antibiotics will have more of an
affect on one bacteria than another. For this reason
our antibiotics were more affective on
pediococcus than e-coli. The only antibiotic that
killed e-coli, other than our positive control, was
the higher concentration of DTAB. Nisin, SDS,
lysozyme, and DTAB all had a kill zone in the
pediococcus plate. Our control, ampicillin, was
by far the most effective antibiotic on that plate.
There are a lot of drugs that will do many things
to different bacterium. The first question we
had was, “What is most effective on both
plates?” We found that DTAB worked well in
both bacterium, sometimes with better kill zones
than our control. In this experiment we have
decided that DTAB would do best in the use of
coating catheters.
A special thanks to our mentor, Clayton Jeffries and Dr. Michelle Bothwell for allowing
us to use her lab.