Abstract:
Vibrio anguillarum is a pathogen for several fish and shellfish species. Its ecology is influenced by diverse factors, including bacteriophages. Here, we identify and characterize a new temperate bacteriophage (Valp1) of V. anguillarum. Valp1 is a myovirus with a 60 nm head and a 90 nm contractile tail. Its double-stranded DNA genome of 42,988 bp contains 68 genes, including a protelomerase gene, typical of telomeric phages. Valp1 inhibits the growth of the virulent strain of V. anguillarum PF4, while the derived lysogenic strain P1.1 presents a slight reduction in its growth but is not affected by the presence of Valp1. Both strains present similar virulence in a larval zebrafish (Danio rerio) model, and only slight differences have been observed in their biochemical profile. Co-culture assays reveal that PF4 and P1.1 can coexist for 10 h in the presence of naturally induced Valp1, with the proportion of PF4 ranging between 28% and 1.6%. By the end of the assay, the phage reached a concentration of ~108 PFU/mL, and all the non-lysogenic PF4 strains were resistant to Valp1. This equilibrium was maintained even after five successive subcultures, suggesting the existence of a coexistence mechanism between the lysogenic and non-lysogenic populations of V. anguillarum in conjunction with the phage Valp1.
摘要:
anguillarum弧菌是几种鱼类和贝类的病原体。它的生态受到多种因素的影响,包括噬菌体.这里,我们鉴定并鉴定了一种新的温带噬菌体(Valp1)。Valp1是具有60nm头部和90nm收缩尾部的肌病毒。其42,988bp的双链DNA基因组包含68个基因,包括原核端粒酶基因,典型的端粒噬菌体。Valp1抑制了V.anguillarumPF4的强毒株的生长,而衍生的溶原菌株P1.1的生长略有降低,但不受Valp1的影响。两种菌株在幼体斑马鱼(Daniorerio)模型中表现出相似的毒力,在它们的生化特征中只观察到微小的差异。共培养实验表明,在天然诱导的Valp1存在下,PF4和P1.1可以共存10h,PF4的比例在28%至1.6%之间。在实验结束时,噬菌体浓度达到~108PFU/mL,所有非溶源性PF4菌株均对Valp1耐药。即使经过五次连续的继代培养,这种平衡仍得以维持,表明在与噬菌体Valp1结合的anguillarum的溶源性和非溶源性种群之间存在共存机制。