Xi Haishen, Fu Benzhong, Sheng Qiang, Luo Ming, Sun Liying
The Department of Plant Pathology, College of Agronomy at Xinjiang Agricultural University/Key Laboratory of Detection and Control of Agricultural and Forest Pests, Urumqi 830052, China.
Ministry of Agriculture and Rural Affairs Key Laboratory for Pests and Diseases Control of Northwest Arid Oasis Agricultural Foreign Invasion Species, Urumqi 830052, China.
Viruses. 2024 Mar 26;16(4):509. doi: 10.3390/v16040509.
Fire blight, caused by the bacterium , is a major threat to pear production worldwide. Bacteriophages, viruses that infect bacteria, are a promising alternative to antibiotics for controlling fire blight. In this study, we isolated a novel bacteriophage, RH-42-1, from Xinjiang, China. We characterized its biological properties, including host range, plaque morphology, infection dynamics, stability, and sensitivity to various chemicals. RH-42-1 infected several strains but not all. It produced clear, uniform plaques and exhibited optimal infectivity at a multiplicity of infection (MOI) of 1, reaching a high titer of 9.6 × 10 plaque-forming units (PFU)/mL. The bacteriophage had a short latent period (10 min), a burst size of 207 PFU/cell, and followed a sigmoidal one-step growth curve. It was stable at temperatures up to 60 °C but declined rapidly at higher temperatures. RH-42-1 remained viable within a pH range of 5 to 9 and was sensitive to extreme pH values. The bacteriophage demonstrates sustained activity upon exposure to ultraviolet radiation for 60 min, albeit with a marginal reduction. In our assays, it exhibited a certain level of resistance to 5% chloroform (CHCl), 5% isopropanol (CHO), and 3% hydrogen peroxide (HO), which had little effect on its activity, whereas it showed sensitivity to 75% ethanol (CHOH). Electron microscopy revealed that RH-42-1 has a tadpole-shaped morphology. Its genome size is 14,942 bp with a GC content of 48.19%. Based on these characteristics, RH-42-1 was identified as a member of the family, genus. This is the first report of a bacteriophage in this genus with activity against .
由细菌引起的火疫病是全球梨生产的主要威胁。噬菌体是一种感染细菌的病毒，是控制火疫病的一种有前景的抗生素替代品。在本研究中，我们从中国新疆分离出一种新型噬菌体RH - 42 - 1。我们对其生物学特性进行了表征，包括宿主范围、噬菌斑形态、感染动力学、稳定性以及对各种化学物质的敏感性。RH - 42 - 1能感染几种菌株，但并非全部。它产生清晰、均匀的噬菌斑，在感染复数（MOI）为1时表现出最佳感染性，达到9.6×10噬菌斑形成单位（PFU）/mL的高滴度。该噬菌体潜伏期短（10分钟），裂解量为207 PFU/细胞，并遵循S型一步生长曲线。它在高达60°C的温度下稳定，但在更高温度下迅速下降。RH - 42 - 1在pH值5至9的范围内仍具活力，对极端pH值敏感。该噬菌体在暴露于紫外线辐射60分钟后仍表现出持续活性，尽管略有降低。在我们的试验中，它对5%氯仿（CHCl）、5%异丙醇（CHO）和3%过氧化氢（HO）表现出一定程度的抗性，这些对其活性影响不大，而它对75%乙醇（CHOH）敏感。电子显微镜显示RH - 42 - 1具有蝌蚪状形态。其基因组大小为14,942 bp，GC含量为48.19%。基于这些特征，RH - 42 - 1被鉴定为 科 属的成员。这是该属中具有抗 活性的噬菌体的首次报道。
