Abstract：
Lytic bacteriophages are re-considered as a solution to resolve antibiotic-resistant rampage. Despite frequent foodborne outbreaks caused by the top six non-O157 Shiga-toxin-producing Escherichia coli (STEC), the current interventions are not sufficiently effective against each serogroup, particularly O45. Therefore, this study aimed to characterize a new short-tailed phage, vB_EcoP-Ro45lw (or Ro45lw), as an alternative antimicrobial agent for STEC O45 strains. Phage Ro45lw belongs to the Kayfunavirus genus within the Autographiviridae family and shares no close evolutionary relationship with any reference phages. Ro45lw contains a tail structure composed of a unique tail fiber and tail tubular proteins A and B, likely to produce enzymatic activity against the target bacterial cells besides structural function. Additionally, the phage genome does not contain virulent, antibiotic-resistant, or lysogenic genes. The phage has a latent period of 15 min with an estimated burst size of 55 PFU/CFU and is stable at a wide range of pH (pH4 to pH11) and temperatures (30 °C to 60 °C). Regardless of the MOIs (MOI = 0.1, 1, and 10) used, Ro45lw has a strong antimicrobial activity against both environmental (E. coli O45:H-) and clinical (E. coli O45:H2) strains at 25 °C. These findings indicate that phage Ro45lw has antimicrobial potential in mitigating pathogenic STEC O45 strains.
摘要：
裂解噬菌体被重新考虑为解决抗生素抗性横冲直撞的解决方案。尽管由前六种非O157产志贺毒素的大肠杆菌（STEC）引起的食源性暴发频繁，目前的干预措施对每个血清群都不够有效，尤其是O45。因此,这项研究旨在表征一种新的短尾噬菌体，vB_EcoP-Ro45lw(或Ro45lw),作为STECO45菌株的替代抗菌剂。噬菌体Ro45lw属于自拟病毒科中的Kayfunavirus属，与任何参考噬菌体都没有密切的进化关系。Ro45lw含有由独特的尾纤维和尾管状蛋白A和B组成的尾结构，除了结构功能外，还可能对目标细菌细胞产生酶活性。此外,噬菌体基因组不含有毒力，耐抗生素，或溶源性基因。噬菌体的潜伏期为15分钟，估计爆发大小为55PFU/CFU，并且在宽范围的pH（pH4至pH11）和温度（30°C至60°C）下稳定。不管使用的MOI（MOI=0.1、1和10），Ro45lw对环境(E.大肠杆菌O45：H-）和临床（E.大肠杆菌O45:H2)菌株在25℃这些发现表明噬菌体Ro45lw在减轻致病性STECO45菌株中具有抗微生物潜力。
