Lee Dongwook, Im Jintaek, Na Hongjun, Ryu Sangryeol, Yun Cheol-Heui, Han Seung Hyun
Department of Oral Microbiology and Immunology, DRI, and BK21 Plus Program, School of Dentistry, Seoul National University, Seoul, South Korea.
Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, Center for Food and Bioconvergence, Seoul National University, Seoul, South Korea.
Front Microbiol. 2019 Dec 17;10:2877. doi: 10.3389/fmicb.2019.02877. eCollection 2019.
is a Gram-positive, facultative anaerobic bacterium frequently found in the gastrointestinal tract, oral cavity, and periodontal tissue. Although it is considered a commensal, it can cause bacteremia, endocarditis, endodontic infections, and urinary tract infections. Because antibiotics are cytotoxic not only to pathogens, but also to health-beneficial commensals, phage therapy has emerged as an alternative strategy to specifically control pathogenic bacteria with minimal damage to the normal flora. In this study, we isolated a novel phage, phage vB_EfaS_HEf13 (phage HEf13), with broad lytic activity against 12 strains of among the three laboratory strains and 14 clinical isolates of evaluated. Transmission electron microscopy showed that phage HEf13 has morphological characteristics of the family . Phage HEf13 was stable at a wide range of temperature (4-60°C) and showed tolerance to acid or alkaline (pH 3-12) growth conditions. Phage HEf13 had a short latent period (25 min) with a large burst size (approximately 352 virions per infected cell). The lytic activity of phage HEf13 at various multiplicities of infection consistently inhibited the growth of diverse clinical isolates of without any lysogenic process. Moreover, phage HEf13 showed an effective lytic activity against on human dentin infection model. Whole genome analysis demonstrated that the phage HEf13 genome contains 57,811 bp of double-stranded DNA with a GC content of 40.1% and 95 predicted open reading frames (ORFs). Annotated functional ORFs were mainly classified into four groups: DNA replication/packaging/regulation, phage structure, host cell lysis, and additional functions such as RNA transcription. Comparative genomic analysis demonstrated that phage HEf13 is a novel phage that belongs to the lineage. Furthermore, the results of multiple sequence alignment showed that polymorphism of phage infection protein of (PIP) contributes to determine the host specificity of phage HEf13 against various strains. Collectively, these results suggest that phage HEf13 has characteristics of a lytic phage, and is a potential therapeutic agent for treatment or prevention of -associated infectious diseases.
是一种革兰氏阳性兼性厌氧菌，常见于胃肠道、口腔和牙周组织。尽管它被认为是共生菌，但它可引起菌血症、心内膜炎、牙髓感染和尿路感染。由于抗生素不仅对病原体具有细胞毒性，而且对有益健康的共生菌也有影响，噬菌体疗法已成为一种替代策略，可在对正常菌群造成最小损害的情况下特异性控制病原菌。在本研究中，我们分离出一种新型噬菌体，噬菌体vB_EfaS_HEf13（噬菌体HEf13），对评估的3株实验室菌株和14株临床分离株中的12株具有广泛的裂解活性。透射电子显微镜显示噬菌体HEf13具有该噬菌体科的形态特征。噬菌体HEf13在较宽的温度范围（4-60°C）内稳定，并且对酸性或碱性（pH 3-12）生长条件具有耐受性。噬菌体HEf13潜伏期短（25分钟），裂解量较大（每个感染细胞约352个病毒粒子）。噬菌体HEf13在不同感染复数下的裂解活性持续抑制各种临床分离株的生长，且无任何溶原过程。此外，噬菌体HEf13在人牙本质感染模型上对具有有效的裂解活性。全基因组分析表明，噬菌体HEf13基因组包含57,811 bp的双链DNA，GC含量为40.1%，预测有95个开放阅读框（ORF）。注释的功能性ORF主要分为四组：DNA复制/包装/调控、噬菌体结构、宿主细胞裂解以及RNA转录等其他功能。比较基因组分析表明噬菌体HEf13是一种属于该噬菌体谱系的新型噬菌体。此外，多序列比对结果表明，粪肠球菌噬菌体感染蛋白（PIP）的多态性有助于确定噬菌体HEf13对各种粪肠球菌菌株的宿主特异性。总体而言，这些结果表明噬菌体HEf13具有裂解性噬菌体的特征，是治疗或预防粪肠球菌相关传染病的潜在治疗剂。
