Tajuddin Sofiah, Khan Asif M, Chong Li Chuin, Wong Chuan Loo, Tan Jia Sen, Ina-Salwany Md Yasin, Lau Han Yih, Ho Kok Lian, Mariatulqabtiah Abdul Razak, Tan Wen Siang
Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Selangor, 43400, UPM Serdang, Malaysia.
Centre for Bioinformatics, School of Data Sciences, Perdana University, 50490, Kuala Lumpur, Malaysia.
Appl Microbiol Biotechnol. 2023 Feb;107(2-3):749-768. doi: 10.1007/s00253-022-12312-3. Epub 2022 Dec 15.
Vibrio alginolyticus is a Gram-negative bacterium commonly associated with mackerel poisoning. A bacteriophage that specifically targets and lyses this bacterium could be employed as a biocontrol agent for treating the bacterial infection or improving the shelf-life of mackerel products. However, only a few well-characterized V. alginolyticus phages have been reported in the literature. In this study, a novel lytic phage, named ΦImVa-1, specifically infecting V. alginolyticus strain ATCC 17749, was isolated from Indian mackerel. The phage has a short latent period of 15 min and a burst size of approximately 66 particles per infected bacterium. ΦImVa-1 remained stable for 2 h at a wide temperature (27-75 °C) and within a pH range of 5 to 10. Transmission electron microscopy revealed that ΦImVa-1 has an icosahedral head of approximately 60 nm in diameter with a short tail, resembling those in the Schitoviridae family. High throughput sequencing and bioinformatics analysis elucidated that ΦImVa-1 has a linear dsDNA genome of 77,479 base pairs (bp), with a G + C content of ~ 38.72% and 110 predicted gene coding regions (106 open reading frames and four tRNAs). The genome contains an extremely large virion-associated RNA polymerase gene and two smaller non-virion-associated RNA polymerase genes, which are hallmarks of schitoviruses. No antibiotic genes were found in the ΦImVa-1 genome. This is the first paper describing the biological properties, morphology, and the complete genome of a V. alginolyticus-infecting schitovirus. When raw mackerel fish flesh slices were treated with ΦImVa-1, the pathogen loads reduced significantly, demonstrating the potential of the phage as a biocontrol agent for V. alginolyticus strain ATCC 17749 in the food. KEY POINTS: • A novel schitovirus infecting Vibrio alginolyticus ATCC 17749 was isolated from Indian mackerel. • The complete genome of the phage was determined, analyzed, and compared with other phages. • The phage is heat stable making it a potential biocontrol agent in extreme environments.
溶藻弧菌是一种革兰氏阴性菌，通常与鲭鱼中毒有关。一种能特异性靶向并裂解这种细菌的噬菌体可被用作生物防治剂，用于治疗细菌感染或延长鲭鱼产品的保质期。然而，文献中仅报道了少数特征明确的溶藻弧菌噬菌体。在本研究中，从印度鲭鱼中分离出一种新型裂解性噬菌体，命名为ΦImVa-1，它能特异性感染溶藻弧菌ATCC 17749菌株。该噬菌体的潜伏期很短，仅15分钟，每个被感染细菌的爆发量约为66个粒子。ΦImVa-1在较宽的温度范围（27-75°C）和pH值5至10的范围内2小时内保持稳定。透射电子显微镜显示，ΦImVa-1具有直径约60nm的二十面体头部和短尾巴，类似于裂病毒科的噬菌体。高通量测序和生物信息学分析表明，ΦImVa-1具有一个77479个碱基对（bp）的线性双链DNA基因组，G+C含量约为38.72%，预测有110个基因编码区（106个开放阅读框和4个tRNA）。该基因组包含一个极大的病毒体相关RNA聚合酶基因和两个较小的非病毒体相关RNA聚合酶基因，这是裂病毒的特征。在ΦImVa-1基因组中未发现抗生素基因。这是第一篇描述感染溶藻弧菌的裂病毒的生物学特性、形态和完整基因组的论文。用ΦImVa-1处理生鲭鱼肉片后，病原体载量显著降低，证明了该噬菌体作为食品中溶藻弧菌ATCC 17749生物防治剂的潜力。
• 从印度鲭鱼中分离出一种新型裂病毒，可感染溶藻弧菌ATCC 17749。
• 确定、分析了该噬菌体的完整基因组，并与其他噬菌体进行了比较。
• 该噬菌体具有热稳定性，使其成为极端环境下潜在的生物防治剂。
