1株宽噬菌谱鸡白痢沙门氏菌噬菌体的分离及生物学特性分析

Isolation and Biological Properties Analysis of a Salmonella Pullorum Lytic Phage with Wide Host Range

本研究采用双层琼脂平板法从现代化肉鸡养殖场采集的粪便、污水和垫料样品中分离宽噬菌谱鸡白痢沙门氏菌烈性噬菌体,并通过透射电子显微镜观察、噬菌谱分析、热稳定性、pH稳定性、最佳感染复数及一步生长曲线等对分离纯化的噬菌体进行生物学特性分析。结果显示,试验成功分离纯化出一株鸡白痢沙门氏菌噬菌体,命名STP98-a。该噬菌体噬菌斑直径4~5mm,圆形透明,无晕圈,其头部偏椭圆形,长径约61nm,横径约67nm,尾长约112nm,直径约10nm,属于长尾噬菌体科;能裂解不同血清型鸡白痢沙门氏菌和肠炎沙门氏菌肠亚种,噬菌谱宽;在30~60℃保持高活性;在pH 3.0~12.0稳定;最佳感染复数为0.001;一步生长曲线结果显示,其感染宿主菌潜伏期为5min,裂解期为135min,裂解量为93。综上所述,STP98-a为一株宽噬菌谱鸡白痢沙门氏菌烈性噬菌体,可用于鸡白痢沙门氏菌噬菌体制剂的研发。

The study was aimed to separate a Salmonella Pullorum lytic phage with wide host range using the double-layer agar culture method.The feces,sewage and padding were collected from the modern broiler farms.And the biological parameters of the lytic phage were assayed,including the transmission electron microscopy observation,determination of host range,thermal stability,pH stability,optimal multiplicity of infection(MOI)and one-step growth curve drawing.The results showed that a lytic phage against Salmonella Pullorum was successfully isolated and purified which was named as STP98-a.Its plaques were round and transparent and the sizes were about 4 to 5 mm in diameter.It had an elliptical head with approximately 61 nm in diameter,67 nm in transverse diameter and had a long tail with 112 nm in length,10 nm in diameter,indicating it belonged to Siphoviridae.Phage STP98-a could lyse Salmonella Pullorum and Salmonella enterica subsp.enterica with a wide host range.The phage was stable with a wide range of temperature(30 to 60℃)and pH(3.0 to 12.0).The optimal MOI was 0.001.The one-step growth curve showed that the latent time and burst time of STP98-a were 5 and 135 min,respectively,and the burst size was 93.In conclusion,STP98-a was a Salmonella Pullorum lytic phage with wide host range that could serve as a promising phage preparations against Salmonella Pullorum.