摘要
目的了解肺炎克雷伯菌裂解性噬菌体PF23的生物学特性,观察其对小鼠全身感染的疗效。方法电镜观察噬菌体PF23的形态,一步生长曲线以及对温度和pH的敏感性;提取噬菌体基因组,酶切法鉴定其核酸类型,并初步估算其基因组大小;建立小鼠全身感染模型,观察PF23的治疗效果。结果 PF23的噬菌斑为有晕清晰透明圆斑,直径约2mm;电镜观察PF23具有尾噬菌体目,长尾病毒科病毒的形态特征;其在〈50℃的温度下及pH 4～9范围内稳定性好。一步生长曲线显示其潜伏期约为11min,裂解量约为41PFU/细胞。其基因组核酸不能被双链DNA限制性内切酶KpnI、EcoRI和HindIII切开,但能被BamHI切开,且酶片段大小合计〉27kb。用PF23治疗由其宿主菌所致全身感染小鼠,小鼠的生存期均〉2d,7d存活率为37.5%;未治疗对照组小鼠1d内均死亡。结论肺炎克雷伯菌的噬菌体PF23潜伏期短,有较好的热稳定性和酸碱稳定性,治疗小鼠肺炎克雷伯菌全身感染效果显著,值得进一步研究。
Objective The characterization of PF23 that infects multi-drug resistant Klebsiella pneumoniae clinical isolates was studied.Moreover,the curative effect of treating systemic infection caused by K.pneumoniain mice was also investigated. Methods The morphology of phage PF23 was observed with electron microscope.The one-step growth curve,host range,and stability of PF23 were also investigated.In order to indentify the type of nucleic acid and the size of its genome,the phage nucleic acid was extracted and digestion by enzyme.The curative effect of PF23 was also investigated by mice model with fatal K.pneumoniae-induced systemic infection. Results PF23 could form clear and transparent plaque（2mm）with halo on the bacterial lawns.The results of electron microscope show that it belongs to caudovirales,Styloviridae.PF23 was stable under 50 ℃ and a wide range of pH（4to 9）.One step growth curve shows that PF23 has a short latent period（about 11min）,approximately 41PFU/cells burst size.The genome of PF23 is greater than 27 kb in length according to the result of digesting by BamHI,but it was difficult to be digested by KpnI,EcoRI and HindIII.The survival of systemic infection mice treated with PF23 was significant increased.All mice were alive more than two days,and the survival rate was 37.5%after 7days.While the control group without treatment all died within 1day. Conclusion PF23,a strain of K.pneumoniae lytic phage,exhibited a short latent period and resistance to both pH and temperature.Moreover,it shows significant treatment efficacy against systemic infection caused by K.pneumoniain mice.Apparently,further research on it should be carried out.
出处
《中国病原生物学杂志》
CSCD
北大核心
2016年第9期808-811,共4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)
关键词
肺炎克雷伯菌
噬菌体
生物学特性
噬菌体治疗
全身感染
Klebsiella pneumoniae
bacteriophage
characterization
phage therapy
systemic infection
