Transcript McKinstry Presentation - Central Catholic High School

Does Vicks VapoRub
Affect Staphylococcus
epidermidis
Survivorship?
Robert McKinstry
Central Catholic High School
Staphylococcus epidermidis
Infections
• Staphylococcus epidermidis infections are
associated with intravascular devices such
as prosthetic heart valves, shunts,
prosthetic joints, and catheters.
• Catheter infections lead to serious
inflammation and septicemia.
• Can also cause endocarditis
S. epidermidis Virulence and
Treatment
• S. epidermidis produces slime layers
which form a hydrophobic biofilm.
• The biofilm acts as a diffusion barrier to
antibiotics and host defenses.
• S. epidermidis commonly found on the
skin may be resistant to several commonly
used antibiotics.
• These antibiotics include penicillin,
amoxicillin, and methicillin.
Staphylococcus epidermidis
• Gram (+) bacteria, coagulase-negative
cocci, that is part of normal flora
• Opportunistic pathogen
• Leading pathogen of nosocomial infections
• Produces a glycocalyx “slime” that acts as
a glue which adheres the bacteria to
plastics and cells and contributes to
antibiotic resistance.
Vicks VapoRub
• Is used to relieve chest or throat
congestion
• Is used to alleviate sore muscles
• Has some antibacterial properties
• Has and is being used to treat
toenail and fingernail fungal
infections.
Vicks VapoRub Ingredients
• Active Ingredients:
• camphor 4.8% (cough suppressant and topical
analgesic),
eucalyptol 1.2% (cough suppressant),
menthol 2.6% (cough suppressant and topical
analgesic)
• Inactive ingredients:
• cedarleaf oil, nutmeg oil, petrolatum, thymol,
and turpentine oil
Purpose
To determine if Vick’s VapoRub
has an effect on
Staphylococcus epidermidis
survivorship in vitro.
Hypotheses
• Null hypothesis: Vicks VapoRub does
not affect Staphylococcus epidermidis
survivorship in vitro.
• Alternative hypothesis: Vicks
VapoRub does affect Staphylococcus
epidermidis survivorship in vitro.
Materials
•Vicks
VapoRub
• Labeling tape
• Ethanol
• Latex gloves
• Staphylococcus epidermidis
•Micropipettes
•Ten micro tubes
• LB media (0.5% yeast
extract, 1% tryptone, 1%
sodium chloride).
•Permanent marker
•Liquid ampicillin
•
•
•
•
•
•
•
•
Sterile Dilution Fluid
(100mM KH2PO4, 100mM
K2HPO4, 10mM MgSO4,
1mM NaCl)
Turntable
80 Luria Broth agar plates
Bunsen burner
Spread bar
Incubator
Klett Spectrophotometer
Matches
Concentrations of VapoRub on
S. epidermidis
Type of
Procedure
Surface
Contact
(Liquid)
[1/10]
0%
Infusion(5g/1L)
Infusion (1g/1L)
Surface
contact
(Spread)
Infused Directly into LB
Agar
Infused directly
into LB Agar
Melted and
plated
Spread on
Top
Control
May have
blocked cell
access to
LB
N/A
9
9
Limitations
Margin of error in
concentration
Margin of error in
concentration
Irregular
surface
exposure
Number of
Replicates
9
9
5
Variables
N.R. = nonresistant
R. = resistant
Number of Replicates
N.R. Strain on LB
(control)
9
R. Strain on LB
(positive control)
9
N.R. Strain on
VapoRub/LB Agar
9
R. Strain on
VapoRub/LB Agar
9
P = 8.24E-7 (Significant)
Nonresistant Staph.
Response to VapoRub
90
P > .05
80
70
P > .05
60
50
P > .05
P > .05
Liquid Spread
Solid Spread
40
30
20
10
0
High Infused
Low Infused
Method of Application
Control
Ampicillin Resistant Staph. Response
to VapoRub
P = 0.53
P = .003
(Significant)
(Insignificant)
84
82
80
78
76
74
72
70
68
Amp. Resistant
on LB
Lab Strain on
LB
Amp. Resistant
on VapoRun
Lab Strain on
VapoRub
Conclusions
• Vicks VapoRub did not significantly affect the
survivorship of non-ampicillin resistant Staphylococcus
epidermidis.
•
The null hypothesis was accepted.
• Ampicillin resistance itself did not significantly improve
Staphylococcus epidermidis survivorship in LB media.
• Staphylococcus epidermidis treated with Vicks VapoRub
had significantly improved survivorship when made
Ampicillin resistant.
Limitations, Extensions, and Future
Studies
Limitations
•
The Staphylococcus epidermitis plating was not exactly synchronized,
possibly contributing to varying colony counts.
•
A larger sample size may have indicated significance.
•
Infusion was the only reliable method of exposing Staphylococcus epidermidis
to Vicks VapoRub.
Extensions and Future Studies
• Larger sample sizes will be employed in the next round of testing.
• Infusion only will be used.
• Thymol could be used in place of Vicks VapoRub, because literature
sources suggest that thymol is ingredient in VapoRub that kills toenail
fungus.