Rapid Screening of Essential Oils as Substances Which Enhance Antibiotic Activity Using a Modified Well Diffusion Method
Ze-Hua Cui,
Hui-Ling He,
Shuai-Bin Wu,
Chun-Liu Dong,
Si-Ya Lu,
Ti-Jiang Shan,
Liang-Xing Fang,
Xiao-Ping Liao,
Ya-Hong Liu,
Jian Sun
Affiliations
Ze-Hua Cui
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Hui-Ling He
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Shuai-Bin Wu
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Chun-Liu Dong
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
Si-Ya Lu
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Ti-Jiang Shan
College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China
Liang-Xing Fang
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Xiao-Ping Liao
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Ya-Hong Liu
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Jian Sun
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Antimicrobial resistance is recognized as one of the major global health challenges of the 21st century. Synergistic combinations for antimicrobial therapies can be a good strategy for the treatment of multidrug resistant infections. We examined the ability of a group of 29 plant essential oils as substances which enhance the antibiotic activity. We used a modified well diffusion method to establish a high-throughput screening method for easy and rapid identification of high-level enhancement combinations against bacteria. We found that 25 essential oils possessed antibacterial activity against Escherichia Coli ATCC 25922 and methicillin-resistant Staphylococcus aureus (MRSA) 43300 with MICs that ranged from 0.01% to 2.5% v/v. We examined 319 (11 × 29) combinations in a checkerboard assay with E. Coli ATCC 25922 and MRSA 43300, and the result showed that high-level enhancement combinations were 48 and 44, low-level enhancement combinations were 214 and 211, and no effects combinations were 57 and 64, respectively. For further verification we randomly chose six combinations that included orange and Petitgrain essential oils in a standard time-killing assay. The results are in great agreement with those of the well diffusion assays. Therefore, the modified diffusion method was a rapid and effective method to screen high-level enhancement combinations of antibiotics and essential oils.
