Wang Yuzhi, Tong Guixiang, Jiang Xinglong, Tu Chuandeng, Cai Hongjiao, Fang Wenhong, Tan Honglian, Weng Qibiao, Wei Xinxian, Lin Mao
State Key Laboratory of Mariculture Breeding, Fisheries College of Jimei University, Xiamen, China.
Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Academy of Fishery Sciences, Nanning, China.
Front Vet Sci. 2024 Jul 18;11:1415685. doi: 10.3389/fvets.2024.1415685. eCollection 2024.
is particularly harmful to freshwater aquaculture, and the search for phage is an effective biological control method, but reports of possible temperate phages and their mutants are rare in this field. In this study, a virulent phage highly homologous to prophage in the genomes of was collected and preliminary biological characterization was carried out to understand its nature.
Water samples taken from eel ponds in Fujian, China were combined with the strain. Spot test method and double-layer agar plate assay was used for confirmation and purification. Phage virions were observed using transmission electron microscope. A total of 68 strains of . were used to determine the host range. MOI groups of 1,000, 100, 10, 1, 0.1, 0.01, 0.001, 0.0001, 0.00001 were prepared to detect the optimal MOI. The conditions of thermal stability assay were set as 30, 40, 50, 60, 70 and 80°C for 1 h, respectively, and conditions of acid and alkali stability assay were set as 2.0, 4.0, 6.0, 8.0, 10.0 and 12.0 of pH. MOI of 0.01 and 0.1, respectively, are set to determine the inhibitory capacity of phage.
A novel virulent phage designated phiA051 has been isolated from aquaculture water. Electron microscopic observation showed that the phage phiA051 was composed of an icosahedral capsid. The phage phiA051 possesses an optimal multiplicity of infection (MOI) of 0.01, and its burst size was 108 PFU/cell. The phage maintained a high viability at temperatures of 30-50°C or pH 6.0-10.0 for 1 h. Phage phiA051 has certain potentials in rapidly inhibiting the spread of pathogen early in the outbreak, and it has a linear dsDNA with GC content of 60.55% and a total length of 32,212 bp, including 46 ORFs.
The phage phiA051 behaved as a virulent phage. However, the BLASTN result showed that 23 of the top 25 hits were genomes of Aeromonas strains. It was suggested that phiA051 was probably derived from some prophage in the chromosome of Aeromonas. Further investigation of the mechanism how phage phiA051 transforms from a temperate phage to a virulent phage will provide a unique perspective and idea to explore the potential of prophages.
[具体物质或因素]对淡水养殖危害极大，寻找噬菌体是一种有效的生物防治方法，但在该领域关于可能的温和噬菌体及其突变体的报道很少。在本研究中，收集了一种与[相关细菌名称]基因组中的前噬菌体高度同源的烈性噬菌体，并进行了初步生物学特性分析以了解其性质。
将取自中国福建鳗鱼池塘的水样与[相关细菌名称]菌株混合。采用点滴试验法和双层琼脂平板测定法进行确认和纯化。使用透射电子显微镜观察噬菌体病毒粒子。总共使用68株[相关细菌名称]来确定宿主范围。制备感染复数（MOI）为1,000、100、10、1、0.1、0.01、0.001、0.0001、0.00001的组别以检测最佳MOI。热稳定性测定的条件分别设定为30、40、50、60、70和80°C处理1小时，酸碱稳定性测定的条件设定为pH值2.0、4.0、6.0、8.0、10.0和12.0。分别设定MOI为0.01和0.1来确定噬菌体的抑制能力。
从养殖水中分离出一种新型烈性[噬菌体名称]噬菌体，命名为phiA051。电子显微镜观察表明，噬菌体phiA051由二十面体衣壳组成。噬菌体phiA051的最佳感染复数（MOI）为0.01，其裂解量为108 PFU/细胞。该噬菌体在30 - 50°C或pH值6.0 - 10.0的条件下处理1小时仍保持高活性。噬菌体phiA051在病原体爆发早期快速抑制其传播方面具有一定潜力，它具有一条线性双链DNA，GC含量为60.55%，全长32,212 bp，包含46个开放阅读框。
噬菌体phiA051表现为烈性噬菌体。然而，BLASTN结果显示，前25个匹配项中有23个是气单胞菌属菌株的基因组。这表明phiA051可能源自气单胞菌染色体中的某些前噬菌体。进一步研究噬菌体phiA051如何从温和噬菌体转变为烈性噬菌体的机制，将为探索前噬菌体的潜力提供独特的视角和思路。
