Susceptibility of Antibacterial Chemicals on Pseudomonas aeruginosa

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Susceptibility of Antibacterial Chemicals on
Pseudomonas aeruginosa

• Research performed by
• Clayton Brady
• Health Science Biology Major
• Tennessee Technological University

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Introduction

• Many diseases arise from bacteria that grow
  resistant to the agents that are made to combat
  them. 
• Through new research, scientists can develop new
  antimicrobial agents and antibiotics to ensure
  the elimination of a bacterium for a limited
  period of time. 
•   Pseudomonas  aeruginosa is responsible for 16
  of nosocomial pneumonia cases , 12 of
  hospital-acquired urinary tract infections , 8
  of surgical wound infections , and 10 of
  bloodstream infections.

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Objective/Hypothesis

• The objective of my research is to determine if
  chemicals commonly found in the antibacterial
  sprays we use so abundantly today can in fact
  render potentially hazardous bacteria, such as
  Pseudomonas aeruginosa, non-viable. 
• I believe that the chemicals will have no effect
  on Pseudomonas aeruginosa.

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Materials

• This experiment required Petri dishes, a
  synthetic stock of Pseudomonas aeruginosa, an
  inoculation loop, and a sterilizer (incinerator)
  for streaking the plates.
• For my chemicals I used Isopropyl Alcohol, 1 M
  Hydrochloric Acid, 5 Hypochlorite Bleach, and
  Vesphene.
• In order to have the bacteria to grow we needed
  an incubation device.
• A ruler was needed to measure the zone of
  inhibition around the discs.
• Finally an autoclave was required to sterilize
  the tools after use.

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Methods

• Using aseptic techniques, the experiment began
  with taking an inoculating loop, sterilizing it
  by way of heating it, and obtaining a sample of
  the bacteria being used.
• The bacteria were then exposed to discs dipped in
  each of the four chemicals.  The dishes were
  separated into quadrants for each of the four
  chemicals tested.
• The bacteria were given a day to grow and on the
  third day the zone of inhibition was observed and
  measured for results.

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Results

• After careful aseptic experimentation, I was able
  to kill Pseudomonas aeruginosa with the
  antibacterial chemicals used in the experimental
  process.
• Vesphene, Isopropyl Alcohol and the 1 M
  Hydrochloric Acid were unable to kill the
  bacteria.

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Results Cont.
Pseudomonas aeruginosa Disk Diffusion Chart Pseudomonas aeruginosa Disk Diffusion Chart Pseudomonas aeruginosa Disk Diffusion Chart Pseudomonas aeruginosa Disk Diffusion Chart
Disc Diffusion Assays      
  Susceptible Resistant Zone of Inhibition
Isopropyl Alcohol    
1 M HCl    
5 hypochlorite bleach   21 millimeters
Vesphene    
       
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Discussion

• The other chemicals, perhaps effective on other
  types of bacteria, were ineffective against
  Pseudomonas aeruginosa.
• I originally wanted to test household sprays
  against this bacteria, but after closer
  examination I realized that the same chemicals
  are in most of the sprays.
• In order to continue my research I changed the
  sprays to specific chemicals commonly used to
  sterilize equipment and tools in hospitals.

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Project Summary

• Pseudomonas aeruginosa is an opportunistic
  pathogen that engages in a plasmid exchange with
  other bacteria making it very hard to kill
  because of its ability to build resistance to
  many cleaners and medicines.
• By subjecting Pseudomonas aeruginosa to chemicals
  found in many hospitals and often used to
  sterilize equipment, I learned that many
  chemicals claiming to kill bacteria do not work
  on Pseudomonas aeruginosa.

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Conclusions

• Bleach (5 hypochlorite solution) was found to be
  an effective antibacterial agent proving my
  hypothesis wrong.
• Although Isopropyl alcohol, vesphene, and HCL
  (1M) may disinfect some bacteria it is not
  effective as an antibacterial agent against
  Pseudomonas aeruginosa.

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Thank you
ANY QUESTIONS??
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