Synergistic Effects of Capric Acid and Colistin against Colistin-Susceptible and Colistin-Resistant <i>Enterobacterales</i>
Yi-Yun Liu,
Zong-Hua Qin,
Hui-Ying Yue,
Phillip J. Bergen,
Li-Min Deng,
Wan-Yun He,
Zhen-Ling Zeng,
Xian-Feng Peng,
Jian-Hua Liu
Affiliations
Yi-Yun Liu
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
Zong-Hua Qin
Guangzhou Insighter Biotechnology Co., Ltd., Guangzhou 510642, China
Hui-Ying Yue
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
Phillip J. Bergen
Biomedicine Discovery Institute, Department of Microbiology, School of Biomedical Sciences, Monash University, Clayton, VIC 3800, Australia
Li-Min Deng
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
Wan-Yun He
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
Zhen-Ling Zeng
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
Xian-Feng Peng
Guangzhou Insighter Biotechnology Co., Ltd., Guangzhou 510642, China
Jian-Hua Liu
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
Colistin is a last-line antibiotic against Gram-negative pathogens. However, the emergence of colistin resistance has substantially reduced the clinical effectiveness of colistin. In this study, synergy between colistin and capric acid was examined against twenty-one Gram-negative bacterial isolates (four colistin-susceptible and seventeen colistin-resistant). Checkerboard assays showed a synergistic effect against all colistin-resistant strains [(FICI, fractional inhibitory concentration index) = 0.02–0.38] and two colistin-susceptible strains. Time–kill assays confirmed the combination was synergistic. We suggest that the combination of colistin and capric acid is a promising therapeutic strategy against Gram-negative colistin-resistant strains.
