Post on 01-Feb-2020
Joseph Brugger Central Catholic High School
11th Grade
Does Lysol affect viral infectivity?
Substances that are applied to non-living objects to destroy microorganisms that are living on the objects.
Work by destroying the cell wall of microbes or interfering with the metabolism.
Frequently used in hospitals, dental surgeries, kitchens, and bathrooms to kill infectious organisms.
Some encompass a wide spectrum, while others are more specific.
First marketed as an effective countermeasure to the Spanish Influenza
All-purpose cleaner
Active Ingredients that compromise cell activity: ◦ Ethanol
◦ Potassium Hydroxide
◦ Lactic Acid
◦ Isopropyl alcohol
Small infectious agents that can replicate only inside the living cells of organisms.
Particles consist of two primary parts: proteins and nucleic acids.
Ubiquitous, they hold the largest biomass in the world.
Disinfectants have been known to alter interaction between viruses and their hosts.
A virus that infects E. coli.
Cannot reproduce extracellularly.
Needs a host cell in which to replicate its genetic material.
Can quickly turn an E. coli cell into a T2-producing factory that releases phages when the cell ruptures.
The first phage that was studied in detail and serves as a common viral model.
Viruses of the lytic cycle are called virulent viruses.
Six-stage cycle.
Large and diverse group of gram (-) bacteria
Free living symbiotes, or pathogens
Live in the intestinal tract of many mammals.
Most strains are not pathogenic
Serve as a common prokaryotic cell model.
Recent studies in toxicology and virology are concerned with the detailed behavior of cultures of Escherichia coli C.
A bacterial strain that has been maintained for many years, mainly in laboratories concerned with bacteriophage synthesis and behavior.
Characterized by its unusual sensitivity to several harmful agents, including the T series of E. coli bacteriophages.
To assess the effects of Lysol on viral infectivity.
Lysol Effects on Viral infectivity was assessed by the growth of plaques within a confluent E. coli C lawn grown on an LB agar plate.
LB (Luria Broth) ◦ 1% tryptone ◦ 0.5% yeast extract ◦ 1% NaCl
Microtubes Micropipettes + Tips Incubator Lysol Gloves + Safety glasses LB agar plates E. coli C T2 Bacteriophage Thermometer Side-arm flask Klett Spectrophotometer
Sterile dilution fluid – 10 mM KH2PO4
– 10 mM K2HPO4
– 1 mM MgSO4
– 0.1 mM CaCl2
– 100 mM NaCl
Macropipettes Water Baths 15 mL Conicles Test Tubes Test Tube racks Top agar
– 10 g tryptone – 5 g yeast extract – 5 g NaCl – 7 g agar
Null Hypothesis: Lysol will not significantly affect the survivorship of the T-2 Virus.
Alternative Hypothesis: Lysol will significantly reduce the survivorship of the T-2 Virus.
1. E. coli C was grown in a sidearm flask to a reading of 60 – 100 K.U. (mid-log phase).
2. The Virus was diluted from 105 to 103 by serial dilution and SDF.
3. The chosen experimental concentrations of 0%, 0.1%, 0.5%, 1%, 5%, and 10% were then created from a solution of Lysol and SDF and placed in 6 respective microtubes.
4. 0.1 mL of phage was then added to the 6 microtubes. 5. The top agar was then melted and kept molten at a
temperature of 47°C in hot water baths. 6. 0.1 mL from each tube, 0.4 mL E. coli, and 2.5 mL top
agar were then mixed in sterile 15mL conical tubes and immediately poured onto LB agar plates.
7. Plates were incubated overnight at 37˚ C. 8. Plaques were counted and recorded.
Tube 1 Tube 2 Tube 3 Tube 4 Tube 5 Tube 6
0% 0.1% 0.5% 1% 5% 10%
Lysol 0 mL 0.001 mL
0.005 mL
0.01 mL
0.05 mL
0.1 mL
SDF 0.9 mL 0.899 mL
0.895 mL
0.89 mL
0.85 mL
0.8 mL
Virus 0.1 mL 0.1 mL
0.1 mL
0.1 mL
0.1 mL
0.1 mL
Final Volume
1 mL 1 mL
1 mL
1 mL
1 mL
1 mL
0
10
20
30
40
50
60
70
80
90
100
0% Lysol 0.1% Lysol 0.5% Lysol 1% Lysol 5% Lysol 10% Lysol
Surv
ivin
g N
um
ber
of
Pla
ques
Concentration of Lysol
P-Value: 6.64*10-35
Concentration T-value Evaluation
0.1% Lysol 11.52 Significant
0.5% Lysol 17.56 Significant
1% Lysol 25.44 Significant
5% Lysol 33.68 Significant
10% Lysol 39.75 Significant
T-Critical = 2.88 Alpha= 0.05
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8 9 10
Surv
ivin
g N
um
ber
of
Pla
ques
% Concentration of Lysol
LD50~ 0.65%
Increased concentrations of Lysol lowered the amount of T-2 plaques that formed.
The results highly suggest that Lysol is an effective disinfectant due to its ability to disrupt the T-2 virus in small concentrations.
The Null Hypothesis can therefore be rejected for all experimental concentrations used as they all significantly varied from the control.
Limitations and Extensions
Limitations Extensions
Plating could have been unsynchronized.
Technical errors in acquiring proper bacteria.
Top Agar technique can vary.
Using more concentrations.
Using different types or brands of disinfectants.
Testing on multiple types of viruses.
Testing for synergistic relationships.
Clark, David. Molecular Biology Simple and Fun. New York: Warner, 2007. Print.
Ferguson, L.R., ed. "Mutation Research." Fundamental and Molecular Mechanisms of Mutagenesis 12.1 (2007): 1+. Print.
"Nutrigenomics." ScienceDirect - Home. Ed. L.R. Ferguson. Elsevier. Web. 05 Nov. 2009. <http://www.ScienceDirect.com>.
"The Newcombe Experiment." The Newcombe Experiment. N.p., 12 Feb. 2008. Web. 2 Jan. 2013.
"E. Coli Bacteria Infection Symptoms, Causes, Treatments." WebMD. WebMD, 14 Mar. 2009. Web. 2 Jan. 2013.
Number of Plaques per Plate
Plate 1
Plate 2
Plate 3
Plate 4
Plate 5
Plate 6
Plate 7
Plate 8
Mean
0% 93 87 89 98 92 88 85 88 90
0.1% 55 74 65 68 70 58 59 64 64.13
0.5% 47 52 58 45 50 54 50 49 50.63
1% 35 38 24 28 32 37 33 36 32.88
5% 15 12 19 22 8 11 16 12 14.38
10% 0 0 0 0 0 1 3 2 0.75
Anova: Single Factor
Concentration of Lysol vs. Plaque Growth
SUMMARY Groups Count Sum Average Variance
0% Lysol 8 720 90 17.14286 0.1% Lyso 8 513 64.125 42.125 0.5% Lysol 8 405 50.625 16.55357 1% Lysol 8 263 32.875 22.98214 5% Lysol 8 115 14.375 20.83929 10% Lysol 8 6 0.75 1.357143
ANOVA Source of Variation SS df MS F P-value F crit Between Groups 43326.25 5 8665.25 429.6818 6.64E-35 2.437693 Within Groups 847 42 20.16667
Total 44173.25 47