【摘要】 利用禽致病性大肠杆菌(avian pathogenic Escherichia coli,APEC)从鸡粪中分离出1株裂解性噬菌体，测定噬菌体相关生物学特性，对噬菌体高通量测序、克隆、表达并纯化得到噬菌体来源解聚酶，通过苯酚硫酸法和联合血清杀菌验证解聚酶的活性。结果显示，该噬菌体感染宿主菌潜伏期小于5 min,感染25 min后达到平台期，噬菌体源性的解聚酶可以特异性降解宿主菌表面多糖，同时可以大幅度提高猴血清对宿主菌的杀灭作用。本试验一方面验证了噬菌体源性解聚酶的活性，另一方面给抗生素替代物提供了一个新的选择。更多还原

【Abstract】 Escherichia coli is common opportunistic pathogenic bacteria in the environment.Pathogenic Escherichia coli has brought great economic losses to food hygiene and animal husbandry.Due to the abuse of antibiotics, bacterial drug for resistance is becoming increasinglysevere.More and more people are looking for natural alternatives toantibiotics.Phages are viruses that specifically infect host bacteria and are widely found in nature, and some phage-derived proteins specifically take part in the invading process.In this study, a lytic phage was isolated from chicken manure using avian pathogenic Escherichia coli(APEC) as host bacteria.Phage genome sequence was obtained through high-throughput sequencing.The activity of depolymerase was verified by phenol sulfuric method and combined serum sterilization.The results showed that the latent period of the phage to infect the host bacterium was less than 5 min, and the plateau phase reached after 25 min of infection, and the bacteriophage-derived depolymerase could specifically degrade the surface polysaccharides of host bacteria and greatly improve the killing effect of monkey serum on host bacteria.This study identified a phage-derived depolymerase that might provide an alternative to antibiotic.更多还原