Abstract：
The emerging global crisis of antibiotic resistance demands new alternative antibacterial solutions. Although bacteriophages have been used to combat bacterial infections for over a century, a dramatic boost in phage studies has recently been observed. In the development of modern phage applications, a scientific rationale is strongly required and newly isolated phages need to be examined in detail. In this study, we present the full characterization of bacteriophages BF9, BF15, and BF17, with lytic activity against extended-spectrum β-lactamases (ESBLs)- and AmpC β-lactamases (AmpC)-producing Escherichia coli, the prevalence of which has increased significantly in livestock in recent decades, representing a great hazard to food safety and a public health risk. Comparative genomic and phylogenetic analysis indicated that BF9, BF15, and BF17 represent the genera Dhillonvirus, Tequatrovirus, and Asteriusvirus, respectively. All three phages significantly reduced in vitro growth of their bacterial host and retained the ability to lyse bacteria after preincubation at wide ranges of temperature (-20-40 °C) and pH (5-9). The results described herein indicate the lytic nature of BF9, BF15, and BF17, which, along with the absence of genes encoding toxins and bacterial virulence factors, represents an undoubted asset in terms of future phage application.
摘要：
正在出现的全球抗生素耐药性危机需要新的替代抗菌解决方案。尽管噬菌体已经被用于对抗细菌感染超过一个世纪，最近观察到噬菌体研究的急剧增加。在现代噬菌体应用的发展中，迫切需要科学的理由，新分离的噬菌体需要详细检查。在这项研究中,我们介绍了噬菌体BF9，BF15和BF17的全部特征，具有对产超广谱β-内酰胺酶（ESBLs）和AmpCβ-内酰胺酶（AmpC）的大肠杆菌的裂解活性，近几十年来，这种疾病在牲畜中的流行率显著上升，对食品安全和公共卫生风险构成极大危害。比较基因组和系统发育分析表明，BF9，BF15和BF17代表Dhillonvirus属，Tequatrovirus,和Asteriusvirus,分别。在广泛的温度范围（-20-40°C）和pH（5-9）下预孵育后，所有三种噬菌体均显着降低了其细菌宿主的体外生长，并保留了裂解细菌的能力。本文所述的结果表明BF9、BF15和BF17的裂解性质，随着编码毒素和细菌毒力因子的基因的缺失，就未来的噬菌体应用而言，这是一项毋庸置疑的资产。
