鲫鱼源维氏气单胞菌噬菌体的分离及生物学特性

Isolation and Biological Charcteristics of Aeromonas veronii-specific Lytic Phage from Crucian Carp(Carassius aumtus)

本试验以鲫鱼源维氏气单胞菌为宿主菌,采用双层平板法从发病鲫鱼肠道中分离维氏气单胞菌的烈性噬菌体,并通过透射电子显微镜对噬菌体的形态进行了观察;同时还对噬菌体的生物学特性进行了测定,包括最适感染复数(MOI)、一步生长曲线、热稳定性、pH稳定性等。结果显示,本试验成功分离获得了1株鲫鱼源维氏气单胞菌噬菌体SJTJYCA01,该噬菌体的噬菌斑圆形透明,边缘清晰整齐,无晕环,其头部直径在45~60 nm,尾部长16~26 nm,属于短尾噬菌体科;噬菌体的最适MOI为0.1;感染宿主菌的潜伏期为20 min,裂解期为40 min,裂解量为57;在温度40℃以下和pH 5~10较为稳定。综上所述,SJTJYCA01为1株鲫鱼源维氏气单胞菌烈性噬菌体,该噬菌体能很好的适应水产养殖环境,在水生动物细菌性疾病防控中具有极大的应用价值。本试验丰富了水产致病菌噬菌体的菌种资源,并为进一步探索噬菌体防控技术提供了科学依据。

A lytic phage was isolated and amplified from the intestine of the diseased Crucian carp(Carassius aumtus)by double-layer plate method,using Aeromonas veronii as the host bacterial.The morphological structures of phage were observed by transmission electron microscope(TEM),and the biological characteristics of the phages,including optimal multiplicity of infection(MOI),one-step growth curve,thermal stability,and pH stability were determined.The resulting Aeromonas veronii-specific phage named SJTJYCA01 formed round and transparent plaque,clear and neat edge,no halo ring.The phage had an head of about 45-60 nm in diameter and a short tail with about 16-26 nm in length,indicating it belonged to Podoviridae.The optimal MOI was 0.1 and the one-step growth curve showed that the latent time and burst time of SJTJYCA01 was 20 and 40 min,respectively,and the burst size was 57.It remained stable between temperature below 40℃ and pH 5-10.Thus,SJTJYCA01 was a virulent phage of Aeromonas veronii from Crucian carp which could adapt to the aquaculture environment and had great possibility in the prevention and control of aquatic animal bacterial diseases.These results help enrich the resources of the lytic bacteriophages against aquatic pathogenic bacteria,and lay a foundation for further exploration of phage control technology.