背景:开发噬菌体疗法和制造噬菌体产品的主要挑战之一是对其疗效的可靠评估,性能,和质量。由于噬菌体毒力本质上很难完全捕获,研究人员已经转向快速但部分不足的评估方法。材料和方法:本研究证明了一种基于三个参数评估噬菌体毒力的标准化定量方法:毒力指数(VP)-定量噬菌体对宿主的毒力,局部毒力(vi)-评估在给定感染复数(MOI)下的杀伤潜力,和MV50-噬菌体达到其最大理论毒力的50%时的MOI。这通过对噬菌体T4、T5和T7的毒力的比较分析表明。结果:在测试条件下,噬菌体T7显示出最高的毒力,其次是噬菌体T4和,最后,噬菌体T5。显示了每个噬菌体的参数如温度和培养基组成对毒力的影响。使用该方法评估噬菌体组合的毒力-例如,对于鸡尾酒配方-也显示有噬菌体T5和T7。结论:该方法为噬菌体毒力的高通量定量评估和噬菌体产品的质量控制提供了平台。它也可以应用于噬菌体筛选,噬菌体菌株的评估,噬菌体突变体,感染条件和/或宿主菌株的易感性,和噬菌体混合物的配方。
Background: One of the main challenges in developing phage therapy and manufacturing phage products is the reliable evaluation of their efficacy, performance, and quality. Since phage virulence is intrinsically difficult to fully capture, researchers have turned to rapid but partially inadequate methods for its evaluation. Materials and Methods: This study demonstrates a standardized quantitative method to assess phage virulence based on three parameters: the virulence index (VP )-quantifying the virulence of a phage against a host, the local virulence (vi )-assessing killing potential at given multiplicities of infection (MOIs), and MV50 -the MOI at which the phage achieves 50% of its maximum theoretical virulence. This was shown through comparative analysis of the virulence of phages T4, T5, and T7. Results: Under the conditions tested, phage T7 displayed the highest virulence, followed by phage T4 and, finally, by phage T5. The impact of parameters such as temperature and medium composition on virulence was shown for each phage. The use of the method to evaluate the virulence of combinations of phages-for example, for cocktail formulation-is also shown with phages T5 and T7. Conclusions: The method presented provides a platform for high-throughput quantitative assessment of phage virulence and quality control of phage products. It can also be applied to phage screening, evaluation of phage strains, phage mutants, infection conditions and/or the susceptibility of host strains, and the formulation of phage cocktails.