The Effectiveness of Disinfectants on

Pseudomonas fluorescens

Michelle Alvarez, Kadija Bangurah &

Paige StoxDepartment of Microbiology

North Carolina State University

Inspiration• How effective

are your everyday household cleaners against bacteria?

• Does it really kill 99% of germs?

Pseudomonas fluorescens

O Gram-Negative

O Rod- Shaped

O Multiple flagella

O Soil and marine environments

O Obligate aerobe

O The optimum growth temperature is 25-30 degrees Celsius

O Produces the antibiotic Mupirocin which treat skin, ear, and eye disorders

O Nonpathogenic and lack virulence factors

Problem/ Hypothesis

O Problem: Which disinfectant will be the most effective on killing Pseudomonas fluorescens?

O Hypothesis: Clorox Bleach Gel will be the most effective on killing Pseudomonas fluorescens.

(9) Disinfectants used: 1. Vinegar- Acetic Acid

2. Hand Sanitizer- ethyl alcohol

3. Clorox Gel Bleach- Sodium Hypoclorite

4. Pine Sol- Pine Oil

5. Hand Soap- Sodium Laureth Sulfate

6. Clorox Wipes- n- Alkyl-Dimethyl Benzyl Ammonium Chlorde

7. Lysol Spray- Hydrogen Peroxde

8. Dish Detergent- Triclosan

9. Shampoo- Ammonium Laureth Sulfate

O Bioscreen C instrument

O 10x Nutrient BrothO dH20O Culture: Pseudomonas

fluorescens

Series of Dilutions: O 1: 20O 1: 30O 1: 50O 1: 100O 1: 1,000O 1: 10,000O 1: 1,000,000O Optimal Density is

measured by the bioscreen C instrument for 60 hours

Method/Materials

Preliminary Trial 1

1 14 27 40 53 66 79 92 1051181311441571701831962092222352482612740

0.5

1

1.5

2

2.5

Vinegar 1

Vinegar 2

Shampoo 1

Shampoo 2

Hand San-itizer 1

Hand San-itizer 2

Clorox Gel 1

Clorox gel 2

Pine Sol 1

Pine Sol 2

Hand Soap 1

Hand Soap 2

Clorox Wipes 1

Clorox Wipes 2

Lysol 1

Lysol 2

Dish De-tergent 1

Dish De-tergent 2

Control Time ( minutes)

Opti

cal D

ensit

y

1:10,000 dilution

1 15 29 43 57 71 85 99 1131271411551691831972112252390

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1:10,000 Dilution

Hand Sanitzer 1Hand Sanitzer 2Pine sol 1Pine sol 2Hand Soap 1Hand Soap 2Clorox gel 1Clorx gel 2Control 1Control 2

Time (Minutes)

Opti

cal D

ensit

y

1:100,000 dilution

1 14 27 40 53 66 79 92 1051181311441571701831962092222350

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1:100,000

Pine Sol 1Pine Sol 2Clorox gel 1Clorox gel 2Control 1Control 2

time(minutes)

Opti

cal D

ensit

y

Conclusion

O The top two disinfectants that worked the best at inhibiting bacteria growth were Pine Sol and Clorox Bleach Gel.

O At 1:100,000 dilution our culture started to grow and both disinfectants were no longer capable of killing our bacteria. Therefore our hypothesis was supported!

Why?

OPine Sol: Pine Oil

OClorox Bleach Gel: Sodium Hypochlorite

Questions?