宽噬菌谱肠炎沙门氏菌噬菌体的生物学特性

摘要

以肠炎沙门氏菌为宿主菌,对从鸡场粪尿污水中分离到的肠炎沙门氏菌噬菌体PSA-6a进行生物学特性鉴定.利用双层平板法分离裂解性噬菌体,并采用噬菌斑形态观察、透射电镜分析、噬菌谱测定、最佳感染复数和一步生长曲线等试验对分离到的噬菌体进行生物学特性鉴定.结果表明该噬菌体在宿主菌ATCC 13076平板上形成的噬菌斑为透亮的空斑,直径为0.5～1.0 mm,边缘清晰,无晕环;它具有宽噬菌谱的特性,不仅可强裂解宿主菌ATCC 13076,还可裂解其他4株沙门氏菌和1株大肠杆菌K88;透射电镜观察显示此噬菌体头部呈圆形,直径约81 nm,有一长尾,尾长约200 nm;一步生长曲线显示PSA-6a潜伏期为60 min,爆发期为50 min,裂解量为22;最佳感染复数为1.%This experiment aimed to isolate a Salmonella enterilidis lytic phage from chicken feces and urine sewage , and study its biological properties. The phage was isolated using double-layer plate method. Its properties were identified by plaque morphology, transmission electron microscopy, detection of host range, maximum multiplicity of infection ( MOI) and one-step growth experiment. A Salmonella enteritidis lytic phage was successfully isolated, named PSA-6a. Its plaque against host strain ATCC 13076 was bright and clear, and the diameter was 0.5-1.0 mm. PSA-6a had broad host range. It not only strongly caused bacteriolysis to host strain, but also lysed another 4 strains of Salmonella and one of Es-herichia coli K88. The ultrastructure under transmission electron microscope showed that PSA-6a had round head with 81nm in diameter, and a long tail with 200 nm in length. One step growth curve showed that the incubation period was 60 min, the burst period was 50 min and the lysis efficiency was 22. Its optimal multiplicity of infection was 1.