Evaluation of the Activity of a Combination of Three Bacteriophages Alone or in Association with Antibiotics on Staphylococcus aureus Embedded in Biofilm or Internalized in Osteoblasts
Evaluation of the Activity of a Combination of Three Bacteriophages Alone or in Association with Antibiotics on Staphylococcus aureus Embedded in Biofilm or Internalized in Osteoblasts
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DOI：
10.1128/aac.02231-19
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发表时间：
2020-03-01
影响因子：
4.9
通讯作者：
Laurent, Frederic
中科院分区：
文献类型：
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作者：
Kolenda, Camille;Josse, Jerome;Laurent, Frederic
金黄色葡萄球菌会导致难以治疗的骨和关节感染（BJIs）。这与其形成生物膜、内化并在成骨细胞内持续存在的能力有关。最近，噬菌体疗法已成为改善此类感染治疗的一种有希望的选择，但关于其对上述特定细菌生活方式的活性的数据仍然很少。我们评估了最近在法国用于同情治疗的三种噬菌体的组合在葡萄球菌生物膜模型和成骨细胞感染模型中对金黄色葡萄球菌HG001的活性，单独或与万古霉素或利福平联合使用。噬菌体对生物膜包埋金黄色葡萄球菌的活性呈剂量依赖性。此外，当噬菌体与最低浓度的抗生素联合使用时，观察到协同效应。只有当细胞被感染时，噬菌体才会渗透到成骨细胞中，这表明噬菌体内化是一种依赖金黄色葡萄球菌的特洛伊木马机制。用噬菌体和万古霉素处理的受感染的成骨细胞的细胞内细菌数量明显高于用溶葡萄球菌素（作为对照条件）处理的细胞，这是由于细胞内缺乏活性，并且在受感染细胞死亡后释放的细菌被迅速杀死。这些结果表明，噬菌体在被感染的成骨细胞内内化后，在细胞内隔室中失活，并且对细胞裂解后释放到细胞外隔室的细菌呈现延迟杀伤作用，从而避免了它们感染其他成骨细胞。所测试的噬菌体组合对嵌入在生物膜中的金黄色葡萄球菌具有高度活性，但对所使用的细胞模型中的细胞内细菌没有活性。
Staphylococcus aureus is responsible for difficult-to-treat bone and joint infections (BJIs). This is related to its ability to form biofilm and to be internalized and persist inside osteoblasts. Recently, bacteriophage therapy has emerged as a promising option to improve treatment of such infections, but data on its activity against the specific bacterial lifestyles presented above remain scarce. We evaluated the activity of a combination of three bacteriophages, recently used for compassionate treatment in France, against S. aureus HG001 in a model of staphylococcal biofilm and a model of osteoblasts infection, alone or in association with vancomycin or rifampin. The activity of bacteriophages against biofilm-embedded S. aureus was dose dependent. In addition, synergistic effects were observed when bacteriophages were combined with antibiotics used at the lowest concentrations. Phage penetration into osteoblasts was observed only when the cells were infected, suggesting a S. aureus-dependent Trojan horse mechanism for internalization. The intracellular bacterial count of bacteria in infected osteoblasts treated with bacteriophages as well as with vancomycin was significantly higher than in cells treated with lysostaphin, used as a control condition, owing to the absence of intracellular activity and the rapid killing of bacteria released after the death of infected cells. These results suggest that bacteriophages are both inactive in the intracellular compartment after being internalized in infected osteoblasts and present a delayed killing effect on bacteria released after cell lysis into the extracellular compartment, which avoids preventing them from infecting other osteoblasts. The combination of bacteriophages tested was highly active against S. aureus embedded in biofilm but showed no activity against intracellular bacteria in the cell model used.