Data_Sheet_1_vB-ApyS-JF1, the First Trueperella pyogenes Phage, Shows Potential as an Alternative Treatment Strategy for Trueperella pyogenes Infections.docx

Trueperella pyogenes (T. pyogenes) is an important opportunistic animal pathogen that causes huge economic losses to the animal husbandry industry. The emergence of bacterial resistance and the unsatisfactory effect of the vaccine have prompted investigators to explore alternative strategies for controlling T. pyogenes infection. Due to the ability of phages to kill multidrug-resistant bacteria, the use of phage therapy to combat multidrug-resistant bacterial infections has attracted attention. In this study, a T. pyogenes phage, vB-ApyS-JF1 (JF1), was isolated from sewage samples, and its whole genome and biological characteristics were elucidated. Moreover, the protective effect of phage JF1 on a mouse bacteremic model caused by T. pyogenes was studied. JF1 harbors a double-stranded DNA genome with a length of 90,130 bp (30.57% G + C). The genome of JF1 lacked bacterial virulence–, antibiotic resistance– and lysogenesis-related genes. Moreover, the genome sequence of JF1 exhibited low coverage (<6%) with all published phages in the NCBI database, and a phylogenetic analysis of the terminase large subunits and capsid indicated that JF1 was evolutionarily distinct from known phages. In addition, JF1 was stable over a wide range of pH values (3 to 11) and temperatures (4 to 50°C) and exhibited strong lytic activity against T. pyogenes in vitro. In murine experiments, a single intraperitoneal administration of JF1 30 min post-inoculation provided 100% protection for mice against T. pyogenes infection. Compared to the phosphate-buffered saline (PBS) treatment group, JF1 significantly (P < 0.01) reduced the bacterial load in the blood and tissues of infected mice. Meanwhile, treatment with phage JF1 relieved the pathological symptoms observed in each tissue. Furthermore, the levels of the inflammatory cytokines tumour necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and interleukin-6 (IL-6) in the blood of infected mice were significantly (P < 0.01) decreased in the phage-treated group. Taken together, these results indicate that phage JF1 demonstrated great potential as an alternative therapeutic treatment against T. pyogenes infection.

化脓隐秘杆菌（Trueperella pyogenes，简称T. pyogenes）是一种重要的机会性动物病原菌，给畜牧业造成了巨大经济损失。细菌耐药性的出现以及疫苗防控效果不佳，促使研究者探索防控化脓隐秘杆菌感染的替代策略。由于噬菌体（phage）可杀灭多重耐药菌，利用噬菌体疗法对抗多重耐药细菌感染已受到广泛关注。本研究从污水样本中分离得到一株化脓隐秘杆菌噬菌体vB-ApyS-JF1（简称JF1），解析了其全基因组序列与生物学特性，并研究了JF1对化脓隐秘杆菌致小鼠菌血症模型的保护作用。
JF1的基因组为双链DNA，全长90130 bp，G+C含量为30.57%。该基因组未携带细菌毒力、抗生素耐药及溶源性相关基因。JF1的基因组序列与NCBI数据库中已收录的所有噬菌体的同源覆盖度均低于6%；通过末端酶大亚基（terminase large subunits）与衣壳蛋白（capsid）的系统发育分析显示，JF1与已知噬菌体的进化关系较远。此外，JF1在宽泛的pH范围（3~11）与温度范围（4~50℃）内均保持稳定，且在体外对化脓隐秘杆菌具有极强的裂解活性。
小鼠实验结果显示，感染后30分钟单次腹腔注射JF1，可使小鼠完全抵御化脓隐秘杆菌感染。与磷酸盐缓冲液（phosphate-buffered saline，简称PBS）处理组相比，JF1可显著降低感染小鼠血液与组织中的细菌载量（P < 0.01）。同时，JF1治疗可缓解各组织的病理损伤症状。此外，噬菌体治疗组感染小鼠血液中的炎症因子肿瘤坏死因子-α（tumour necrosis factor-α，TNF-α）、干扰素-γ（interferon-γ，IFN-γ）与白细胞介素-6（interleukin-6，IL-6）水平均显著降低（P < 0.01）。
综上，本研究结果表明，噬菌体JF1有望成为防控化脓隐秘杆菌感染的新型治疗手段。