Nguyen Tiep K, Peyrusson Frédéric, Dodémont Magali, Pham Nhung H, Nguyen Hoang A, Tulkens Paul M, Van Bambeke Françoise
Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université catholique de Louvain (UCLouvain), Brussels, Belgium.
Department of Pharmaceutical Industry, Hanoi University of Pharmacy, Hanoi, Vietnam.
Front Microbiol. 2020 Nov 23;11:587364. doi: 10.3389/fmicb.2020.587364. eCollection 2020.
may cause relapsing infections. We previously showed that SH1000 surviving intracellularly to bactericidal antibiotics are persisters. Here, we used 54 non-duplicate clinical isolates to assess links between persistence, resistance evolution, and intracellular survival, using moxifloxacin throughout as test bactericidal antibiotic. The relative persister fraction (RPF: percentage of inoculum surviving to 100× MIC moxifloxacin in stationary phase culture for each isolate relative to ATCC 25923) was determined to categorize isolates with low (≤10) or high (>10) RPF. Evolution to resistance (moxifloxacin MIC ≥ 0.5 mg/L) was triggered by serial passages at 0.5× MIC (with daily concentration readjustments). Intracellular moxifloxacin maximal efficacy (E) was determined by 24 h concentration-response experiments [pharmacodynamic model (Hill-Langmuir)] with infected THP-1 monocytes exposed to moxifloxacin (0.01 to 100× MIC) after phagocytosis. Division of intracellular survivors was followed by green fluorescence protein dilution (FACS). Most (30/36) moxifloxacin-susceptible isolates showed low RPF but all moxifloxacin-resistant ( = 18) isolates harbored high RPF. Evolution to resistance of susceptible isolates was faster for those with high vs. low RPF (with SOS response and topoisomerase-encoding genes overexpression). Intracellularly, moxifloxacin E was decreased (less negative) for isolates with high vs. low RPF, independently from resistance. Moxifloxacin intracellular survivors were non-dividing. The data demonstrate and quantitate persisters in clinical isolates of , and show that this phenotype accelerates resistance evolution and is associated with intracellular survival in spite of high antibiotic concentrations. Isolates with high RPF may represent a possible cause of treatment failure not directly related to resistance in patients receiving active antibiotics.
可能导致复发性感染。我们之前表明，在细胞内存活以抵抗杀菌性抗生素的SH1000是持留菌。在此，我们使用54株非重复临床分离株，以莫西沙星作为测试杀菌性抗生素，评估持留性、耐药性演变和细胞内存活之间的联系。确定相对持留菌比例（RPF：相对于ATCC 25923，每种分离株在稳定期培养中存活至100×莫西沙星MIC的接种物百分比），以将RPF低（≤10）或高（>10）的分离株分类。通过在0.5×MIC下连续传代（每日调整浓度）引发耐药性演变（莫西沙星MIC≥0.5mg/L）。细胞内莫西沙星最大效力（E）通过24小时浓度-反应实验[药效学模型（希尔-朗缪尔）]确定，实验中吞噬后感染的THP-1单核细胞暴露于莫西沙星（0.01至100×MIC）。通过绿色荧光蛋白稀释（流式细胞术）追踪细胞内存活菌的分裂。大多数（30/36）对莫西沙星敏感的分离株显示低RPF，但所有耐莫西沙星（=18）的分离株都具有高RPF。RPF高的敏感分离株比RPF低的敏感分离株耐药性演变更快（伴有SOS反应和拓扑异构酶编码基因过表达）。在细胞内，RPF高的分离株与RPF低的分离株相比，莫西沙星E降低（负值减小），与耐药性无关。莫西沙星细胞内存活菌不分裂。数据证明并量化了临床分离株中的持留菌，并表明这种表型加速了耐药性演变，并且尽管抗生素浓度很高，但仍与细胞内存活相关。RPF高的分离株可能是接受活性抗生素治疗的患者治疗失败的一个可能原因，而这与耐药性无直接关系。
