Efflux pumps and β-lactamases are mechanisms of bacterial resistance that exist in Staphylococcus aureus, where both mechanisms are expressed simultaneously in the SA K4100 strain, with its efflux pump being characterized as QacC (Quaternary Ammonium Compounds C). The search for inhibitors of these mechanisms has grown gradually, with research on isolated compounds, including terpenes, which have innumerable biological activities, being common. This study sought to evaluate the antibacterial activity of Terpinolene against the S. aureus K4100 strain, carrying a QacC efflux pump and β-lactamase, as well as to evaluate its toxicity in the Drosophila melanogaster arthropod model. Determination of the Minimum Inhibitory Concentration (MIC) was performed by broth microdilution. Efflux pump inhibition was evaluated by the MIC reduction of Oxacillin and Ethidium Bromide (EtBr). β-Lactamase inhibition was analyzed by the MIC reduction of Ampicillin with Sulbactam. Toxicity was verified by mortality parameters and locomotor assays in D. melanogaster. The results demonstrated that Terpinolene did not present a direct antibacterial activity (MIC ≥ 1024 μg/mL). However, a reduction in MIC was observed when Terpinolene was associated with Oxacillin (161.26–71.83 μg/mL) and EtBr (45.25–32 μg/mL), possibly by a β-lactamase and efflux pump inhibition, thus evidencing a modulatory activity. Terpinolene presented D. melanogaster mortality with an EC₅₀ of 34.6 μL/L within 12 h of exposure. Additionally, Terpinolene presented damage to the locomotor system after the second hour of exposure, with the effect increasing in a concentration-dependent manner. In conclusion, new tests should be carried out to investigate the Terpinolene reinforcement of antibiotic activity and toxic activity mechanisms of action.

外排泵和β-内酰胺酶是金黄色葡萄球菌中存在的细菌抗性机制，其中两种机制在SA K4100菌株中同时表达，其外排泵的特征是QacC（季铵化合物C）。对这些机制的抑制剂的研究已逐渐发展，对具有无数生物活性的分离的化合物，包括萜烯的研究也很普遍。这项研究试图评估萜品洛烯对带有QacC外排泵和β-内酰胺酶的金黄色葡萄球菌K4100菌株的抗菌活性，并评估其在果蝇中的毒性。节肢动物模型。最低抑菌浓度（MIC）的测定是通过肉汤微量稀释进行的。通过MIC降低奥沙西林和溴化乙锭（EtBr）评估外排泵抑制。β-内酰胺酶抑制作用通过舒巴坦的MIC降低氨苄西林来分析。通过死亡率参数和运动试验验证了D. melanogaster的毒性。结果表明，萜品洛烯不具有直接的抗菌活性（MIC≥1024μg/ mL）。但是，当萜品洛烯与奥沙西林（161.26–71.83μg/ mL）和EtBr（45.25–32μg/ mL）结合时，观察到的MIC降低，可能是β-内酰胺酶和外排泵抑制作用，从而证明了其调节活性。萜品洛烯与EC一起表现出D. melanogaster死亡率暴露后12小时内₅₀的34.6μL/ L。另外，在暴露第二小时后，萜品洛烯对运动系统造成损害，其作用以浓度依赖性方式增加。总之，应该进行新的试验来研究萜品洛烯增强抗生素活性和毒性活性的作用机理。