摘要
目的自地下生活污水中分离肺炎克雷伯菌的噬菌体,明确其生物学特性,观察其对小鼠多重耐药肺炎克雷伯菌所致败血症的疗效。方法电镜观察LH-01形态,调查其噬菌谱、生长曲线等生物学特性。建立小鼠败血症感染模型,观察LH-01的疗效。结果 LH-01在其宿主菌的菌苔上形成毒性噬菌体所具有的完全透明的噬菌斑,电镜观察LH-01具典型的有尾噬菌体目短尾病毒科病毒的形态特征。一步生长曲线显示LH-01的潜伏期约为10min,裂解量约为100PFU/细胞。稳定性试验显示LH-01在pH 5~10及50℃和60℃环境均具良好稳定性。LH-01治疗克雷伯菌感染败血症小鼠的存活率为90%,对照组存活率为0,差异有统计学意义(P〈0.001),且无毒副作用。结论 LH-01具有高效的裂菌活性和高稳定性,治疗克雷伯菌感染小鼠败血症有效且安全,有望成为生物抗菌剂,其有效成分有待进一步研究。
Objective This study characterized a novel virulent phage of Klebsiellaisolated from sewage and it examined the efficacy of phage therapy in treating fatal K.pneumoniae-induced septicemia. Methods The morphology of the Klebsiellaphage LH-01 was observed using electron microscopy.One-step growth kinetics,the host range,and the pharmacokinetics of the phage were determined.In an in vitro experiment,LH-01 was used to treat mice with bacteremia caused by clinical isolates of multidrug-resistant K.pneumoniae KP6. Results LH-01 exhibited lytic activity as indicated by clear areas on bacterial lawns.LH-01 was found to have an isometric icosahedral head of approximately 50×63nm connected to a short tail 10 nm long.Morphologically,LH-01 was classified as a member of the Podoviridae family and the Caudovirales order.The phage is highly infectious with a short latent period(10 min)and a large burst size(100PFU/cell).The phage is stable over a wide pH range(5to 10)and at extreme temperatures(between 50℃ and 60℃).Phage treatment significantly improved the survival of mice without any adverse reactions.Without treatment,all mice died within 3days of inoculation via intravenous injection of 107 CFU K.pneumoniae KP6(the LD100 for mice).In contrast,intravenous administration of 107 PFU of the LH-01 phage 2hours after inoculation resulted in a survival rate of90% after 10days(P0.001). Conclusion This study provides experimental evidence that LH-01 has significant efficacy against K.pneumoniaeinfection in mice without causing adverse reactions.The characteristics of the phage LH-01 mean that it is extremely useful as a biological bactericide.
出处
《中国病原生物学杂志》
CSCD
北大核心
2015年第1期25-28,33,共5页
Journal of Pathogen Biology
基金
河南省科技厅重点科技攻关项目(No.142102310440)
河南省医学科技攻关计划项目(No.201303199)