沙门氏菌噬菌体ΦSHDA-1生物学特性及基因组学初步研究

A Preliminary Study on the Characteristics and Genomics Analysis of Salmonella PhageΦSHDA-1

以鼠伤寒沙门氏菌(CMCC50115)为宿主菌,采用双层平板的方法从污水中分离得到一株裂解性噬菌体,命名为ΦSHDA-1,并对其生物学特性及基因组进行了初步研究。结果表明:ΦSHDA-1噬菌斑透亮且边缘清晰,无晕圈;透射电镜观察ΦSHDA-1头部直径为(53±8)nm,尾部长(112±12)nm,属于长尾噬菌体科;最佳感染复数为0.00001;一步生长曲线结果显示潜伏期为25 min,爆发期为30 min,平均裂解量为36.52 PFU/cell;在30~50℃和pH为2~10条件下稳定;且裂解曲线表明,其对鼠伤寒沙门氏菌有良好的裂解效果。全基因组测序共得到6个重叠群,总长度为40523 bp,GC含量为51%。通过Prokka注释,共得到59个编码序列,不含tRNA及rRNA,含有一个裂解酶基因,通过对开放阅读框与CARD以及VFDB进行分析,未发现携带耐药基因和毒力基因。

A virulent phage,named asΦSHDA-1,was isolated from sewage by a double-layer plate method using Salmonella typhimurium(CMCC50115)as the host strain.The preliminary study of its biological characteristics and genome was conducted.The results showed thatΦSHDA-1 plaque was bright and the edge was clear.The transmission electron microscopy showed thatΦSHDA-1 had a head diameter of(53±8)nm and a tail length of(112±12)nm which belong to the Siphoviridae family.The best multiplicity of infection was 0.00001.The one-step growth curve showed the latent period was 25 min and the burst period was 30 min with an average lysis amount of 36.52 PFU/cell.ΦSHDA-1 was stable at 30~50℃and pH 2~10,exhibiting a good lysis effect on Salmonella typhimurium.A total of 6 coutig with length of 40523 bp and 51%of GC were obtained by whole-genome sequence.A total of 59 coding sequences were obtained by Prokka annotation,which contained an lysin gene without tRNA and rRNA.Through the open reading frame and the analysis of CARD and VFDB,no drug resistance genes and virulence genes were detected.