Table_1.XLSX

The deteriorating effectiveness of antibiotics is propelling researchers worldwide towards alternative techniques such as phage therapy: curing infectious diseases using viruses of bacteria called bacteriophages. In a previous paper, we isolated phage EFDG1, highly effective against both planktonic and biofilm cultures of one of the most challenging pathogenic species, the vancomycin-resistant Enterococcus (VRE). Thus, it is a promising phage to be used in phage therapy. Further experimentation revealed the emergence of a mutant resistant to EFDG1 phage: EFDG1r. This kind of spontaneous resistance to antibiotics would be disastrous occurrence, however for phage-therapy it is only a minor hindrance. We quickly and successfully isolated a new phage, EFLK1, which proved effective against both the resistant mutant EFDG1r and its parental VRE, Enterococcus faecalis V583. Furthermore, combining both phages in a cocktail produced an additive effect against E. faecalis V583 strains regardless of their antibiotic or phage-resistance profile. An analysis of the differences in genome sequence, genes, mutations, and tRNA content of both phages is presented. This work is a proof-of-concept of one of the most significant advantages of phage therapy, namely the ability to easily overcome emerging resistant bacteria.抗生素的抗菌效力持续衰退，推动全球研究者转向噬菌体疗法等替代技术——即利用名为噬菌体（bacteriophages）的细菌病毒治疗感染性疾病。在过往研究中，我们分离出噬菌体EFDG1，其对极具临床挑战性的致病菌之一——耐万古霉素肠球菌（vancomycin-resistant Enterococcus, VRE）的浮游菌与生物膜培养物均表现出强效活性，因此该噬菌体是用于噬菌体疗法的极具潜力的候选株。后续实验发现了一株对EFDG1噬菌体产生抗性的突变株EFDG1r。这类对抗生素产生的自发性耐药本会是灾难性的情况，但在噬菌体疗法中仅为微小阻碍。我们随即成功分离出一株新噬菌体EFLK1，实验证实其对耐药突变株EFDG1r及其亲本VRE菌株——粪肠球菌V583（Enterococcus faecalis V583）均具有杀伤活性。此外，将两种噬菌体复配为噬菌体鸡尾酒时，可对粪肠球菌V583菌株产生累加杀菌效应，无论该菌株具备抗生素或噬菌体耐药表型。本研究对这两株噬菌体的基因组序列、基因组成、突变位点及tRNA含量差异进行了分析。本研究验证了噬菌体疗法最核心的优势之一，即可轻松应对新出现的耐药细菌，为其临床应用提供了概念验证（proof-of-concept）。