Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona 60131, Italy.
Department of Materials, Environmental Sciences and Urban Planning, Polytechnic University of Marche, Ancona 60131, Italy.
J Nat Prod. 2021 Apr 23;84(4):993-1001. doi: 10.1021/acs.jnatprod.0c01151. Epub 2021 Apr 13.
The eradication of recurrent (PA) lung infection in cystic fibrosis (CF) patients may be hampered by the development of persistent bacterial forms, which can tolerate antibiotics through efflux pump overexpression. After demonstrating the efflux pump inhibitory effect of the alkaloid berberine on the PA MexXY-OprM efflux pump, in this study, we tested its ability (80/320 μg/mL) to enhance tobramycin (20xMIC/1000xMIC) activity against PA planktonic/biofilm cultures. Preliminary investigations of the involvement of MexY in PA tolerance to tobramycin treatment, performed on the isogenic pair PA K767 (wild type)/K1525 (Δ) growing in planktonic and biofilm cultures, demonstrated that the Δ mutant K1525 produced a lower (100 and 10 000 times, respectively) amount of tolerant cells than that of the wild type. Next, we grew broth cultures of PAO1, PA14, and 20 PA clinical isolates (of which 13 were from CF patients) in the presence of 20xMIC tobramycin with and without berberine 80 μg/mL. Accordingly, most strains showed a greater (from 10- to 1000-fold) tolerance reduction in the presence of berberine. These findings highlight the involvement of the MexXY-OprM system in the tobramycin tolerance of PA and suggest that berberine may be used in new valuable therapeutic combinations to counteract persister survival.
为了克服囊性纤维化（CF）患者肺部反复感染（PA）的问题，可能需要克服持久细菌形式的影响，这些细菌可以通过外排泵过度表达来耐受抗生素。在证明生物碱小檗碱对 PA MexXY-OprM 外排泵的外排泵抑制作用后，在本研究中，我们测试了其增强妥布霉素（20xMIC/1000xMIC）对 PA 浮游生物/生物膜培养物活性的能力（80/320μg/mL）。在 PA K767（野生型）/K1525（Δ）的同源对中进行的 MexY 参与 PA 对妥布霉素治疗的耐受性初步研究，该同源对在浮游生物和生物膜培养物中生长，表明Δ突变体 K1525 产生的耐受细胞数量低于野生型（分别为 100 倍和 10,000 倍）。接下来，我们在含有 20xMIC 妥布霉素和/或 80μg/mL 小檗碱的条件下，在肉汤培养物中培养 PAO1、PA14 和 20 株 PA 临床分离株（其中 13 株来自 CF 患者）。相应地，大多数菌株在存在小檗碱的情况下显示出更大的（从 10 到 1000 倍）耐受性降低。这些发现强调了 MexXY-OprM 系统在 PA 妥布霉素耐受性中的作用，并表明小檗碱可能用于新的有价值的治疗组合中，以对抗持久性生存。
