Department of Biological Chemistry, Regional University of Cariri, URCA, Crato, CE, Brazil.
Goncalo Moniz Institute, Oswaldo Cruz Foundation, IGM-FIOCRUZ/BA, Salvador, BA, Brazil.
Curr Drug Metab. 2021;22(2):110-113. doi: 10.2174/1389200221999210104204718.
This study aimed to investigate the potential of limonene as an efflux pump (EP) inhibitor in Staphylococcus aureus strains, RN-4220 and IS-58, which carry EPs for erythromycin (MrsA) and tetracycline (TetK), respectively.
The evolution of bacterial resistance mechanisms over time has impaired the action of most classes of antibiotics. Staphylococcus aureus is a notable bacterium, with high pathogenic potential and demonstrated resistance to conventional antibiotics. Considering the importance of discovering novel compounds to combat antibiotic resistance, our group previously demonstrated the antibacterial properties of limonene, a compound present in the essential oils of several plant species.
This study aimed to investigate the potential of limonene as an efflux pump (EP) inhibitor in Staphylococcus aureus strains RN-4220 and IS-58, which carry EPs for erythromycin (MrsA) and tetracycline (TetK), respectively.
The minimum inhibitory concentrations (MIC) of limonene and other efflux pump inhibitors were determined through the broth microdilution method. A reduction in the MIC of ethidium bromide was used as a parameter of EP inhibition.
While limonene was not shown to exhibit direct antibacterial effects against EP-carrying strains, in association with ethidium bromide and antibiotics, this compound demonstrated enhanced antibacterial activity, indicating the inhibition of the MrsA and TetK pumps.
In conclusion, this pioneering study demonstrated the effectiveness of limonene as an EP inhibitor in S. aureus strains, RN-4220 and IS-58. Nevertheless, further studies are required to characterize the molecular mechanisms associated with limonene-mediated EP inhibition.
本研究旨在探讨柠檬烯作为一种外排泵（EP）抑制剂在分别携带红霉素（MrsA）和四环素（TetK）外排泵的金黄色葡萄球菌 RN-4220 和 IS-58 菌株中的潜力。
随着时间的推移，细菌耐药机制的演变已经削弱了大多数类别的抗生素的作用。金黄色葡萄球菌是一种具有高致病性和对传统抗生素表现出耐药性的重要细菌。考虑到发现新型化合物来对抗抗生素耐药性的重要性，我们的研究小组之前已经证明了柠檬烯的抗菌特性，柠檬烯是几种植物精油中的一种化合物。
本研究旨在探讨柠檬烯作为一种外排泵（EP）抑制剂在分别携带红霉素（MrsA）和四环素（TetK）外排泵的金黄色葡萄球菌 RN-4220 和 IS-58 菌株中的潜力。
通过肉汤微量稀释法测定柠檬烯和其他外排泵抑制剂的最小抑菌浓度（MIC）。溴化乙锭 MIC 的降低被用作 EP 抑制的参数。
虽然柠檬烯本身对携带 EP 的菌株没有直接的抗菌作用，但与溴化乙锭和抗生素联合使用时，这种化合物表现出增强的抗菌活性，表明 MrsA 和 TetK 泵被抑制。
综上所述，这项开创性的研究表明柠檬烯作为金黄色葡萄球菌 RN-4220 和 IS-58 菌株的 EP 抑制剂是有效的。然而，需要进一步的研究来表征与柠檬烯介导的 EP 抑制相关的分子机制。
