Zhao Qiqi, Shi Xinpu, Liu Mingshuai, Ji Lei
School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, 310000, Zhejiang, People's Republic of China.
State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China.
Virus Genes. 2025 Jun 21. doi: 10.1007/s11262-025-02170-2.
Mycobacterium, an opportunistic pathogen, is highly prone to causing infections in humans, and its resistance to antibiotics poses a significant challenge. Phage therapy has emerged as a highly promising alternative treatment. In this study, a bacteriophage infecting Mycobacterium smegmatis was isolated from soil, named MS619, and classified within the class Caudoviricetes. Phages have an icosahedral head (60 ± 2 nm in diameter) and a long, non-contractile tail with a size of 125 ± 2 nm. The genome of MS619 was found to be a double-stranded DNA composed of 48,955 bp, containing 76 open reading frames (ORFs), related to phage packaging, structure, lysin, regulation, and replication. The BLASTN results indicated that MS619 exhibits a high-sequence identity (93%) with Mycobacterium phage Georgie2, a known bacteriophage recorded in the NCBI GenBank database. A typical holin-lysin system was identified in the MS619 genome. The topology of holin was predicted to contain two transmembrane domains, which significantly contribute to antimicrobial activity. No antibiotic resistance- or virulence factor-related genes were detected in the phage. Moreover, the bacteriophage demonstrates biofilm growth inhibition capability. This study led to the isolation of MS619, a bacteriophage exhibiting potential antibacterial efficacy against Mycobacterium infections.
分枝杆菌是一种机会性病原体，极易在人类中引发感染，其对抗生素的耐药性构成了重大挑战。噬菌体疗法已成为一种极具前景的替代治疗方法。在本研究中，从土壤中分离出一种感染耻垢分枝杆菌的噬菌体，命名为MS619，归类于有尾噬菌体目。噬菌体有一个二十面体头部（直径60±2纳米）和一条长的、非收缩性的尾巴，大小为125±2纳米。发现MS619的基因组是由48,955个碱基对组成的双链DNA，包含76个开放阅读框（ORF），与噬菌体包装、结构、溶菌酶、调控和复制有关。BLASTN结果表明，MS619与分枝杆菌噬菌体Georgie2具有高度的序列同一性（93%），Georgie2是NCBI GenBank数据库中记录的一种已知噬菌体。在MS619基因组中鉴定出一个典型的孔蛋白-溶菌酶系统。预测孔蛋白的拓扑结构包含两个跨膜结构域，这对抗菌活性有显著贡献。在噬菌体中未检测到与抗生素耐药性或毒力因子相关的基因。此外，该噬菌体具有生物膜生长抑制能力。本研究导致分离出MS619，这是一种对分枝杆菌感染具有潜在抗菌功效的噬菌体。
