The effect of phenolic compounds (benzoic acid) on the susceptibility of gram-positive and gram-negative bacteria exposed to antibiotics.

School Name

Spring Valley High School

Grade Level

11th Grade

Presentation Topic

Microbiology

Presentation Type

Mentored

Mentor

Mentor: Xiaoming Yang, University of South Carolina School of Microbiology

Oral Presentation Award

1st Place

Written Paper Award

1st Place

Abstract

Benzoic acid is a common phenolic phytochemical found in the natural environment. This phenol has been found to increase the susceptibility of resistant microbes, making it more feasible to kill the microbials by antibiotics. The experiment modeled the effects of phenolic acids by placing them into an agar medium and exposing them to gram-positive and gram-negative bacteria. The antibiotics [Bactrim and Ciprofloxacin] discs were placed on the top of the agar medium and then the inhibition zone was measured after 24 hours to determine the antimicrobial effects of the phenols. It was hypothesized that higher concentrations of phenols would increase the susceptibility of the microbe, allowing the antibiotics to inhibit the gram-positive and gram-negative bacteria. The groups consisting solely of the antibiotic and bacteria served as a controls for the experiment. The concentrations of the phenols in the experimental group increased at similar levels for each phenol, from 0 µg/ml- 800 µg/ml. The hypothesis was partially supported. The gram-positive microbe Staphylococcus aureus was sensitized to both CIP and SXT when exposed to benzoic acid concentrations yielding a p < 0.01 at an α=0.05. Similarly, the gram-negative microbe Pseudomonas aeruginosa was sensitized significantly to CIP when exposed to phenol, having a p < 0.01 at an α=0.05. In comparison, gram-negative microbe Escherichia Coli, proved no statistical significance with a p > 0.01 at an α=0.05. Conclusions were not drawn in comparison to both strains of bacteria, but evidence suggests that bacteria can be sensitized with benzoic acid, as indicated by the successes with antibiotic application.

Location

Wall 224

Start Date

3-25-2017 12:15 PM

Presentation Format

Oral and Written

Group Project

No

COinS
 
Mar 25th, 12:15 PM

The effect of phenolic compounds (benzoic acid) on the susceptibility of gram-positive and gram-negative bacteria exposed to antibiotics.

Wall 224

Benzoic acid is a common phenolic phytochemical found in the natural environment. This phenol has been found to increase the susceptibility of resistant microbes, making it more feasible to kill the microbials by antibiotics. The experiment modeled the effects of phenolic acids by placing them into an agar medium and exposing them to gram-positive and gram-negative bacteria. The antibiotics [Bactrim and Ciprofloxacin] discs were placed on the top of the agar medium and then the inhibition zone was measured after 24 hours to determine the antimicrobial effects of the phenols. It was hypothesized that higher concentrations of phenols would increase the susceptibility of the microbe, allowing the antibiotics to inhibit the gram-positive and gram-negative bacteria. The groups consisting solely of the antibiotic and bacteria served as a controls for the experiment. The concentrations of the phenols in the experimental group increased at similar levels for each phenol, from 0 µg/ml- 800 µg/ml. The hypothesis was partially supported. The gram-positive microbe Staphylococcus aureus was sensitized to both CIP and SXT when exposed to benzoic acid concentrations yielding a p < 0.01 at an α=0.05. Similarly, the gram-negative microbe Pseudomonas aeruginosa was sensitized significantly to CIP when exposed to phenol, having a p < 0.01 at an α=0.05. In comparison, gram-negative microbe Escherichia Coli, proved no statistical significance with a p > 0.01 at an α=0.05. Conclusions were not drawn in comparison to both strains of bacteria, but evidence suggests that bacteria can be sensitized with benzoic acid, as indicated by the successes with antibiotic application.