Molecular Microbiology Laboratory, Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, India.
Interdisciplinary School of Life Sciences, Institute of Science, Banaras Hindu University, Varanasi, India.
Front Cell Infect Microbiol. 2023 Jul 21;13:1173894. doi: 10.3389/fcimb.2023.1173894. eCollection 2023.
Mycobacteriophages are viruses that infect members of genus . Because of the rise in antibiotic resistance in mycobacterial diseases such as tuberculosis, mycobacteriophages have received renewed attention as alternative therapeutic agents. Mycobacteriophages are highly diverse, and, on the basis of their genome sequences, they are grouped into 30 clusters and 10 singletons. In this article, we have described the isolation and characterization of a novel mycobacteriophage Kashi-VT1 (KVT1) infecting mc 155 () and isolated from Varanasi, India. KVT1 is a cluster K1 temperate phage that belongs to family as visualized in transmission electron microscopy. The phage genome is 61,010 base pairs with 66.5% Guanine/Cytosine (GC) content, encoding 101 putative open reading frames. The KVT1 genome encodes an immunity repressor, a tyrosine integrase, and an excise protein, which are the characteristics of temperate phages. It also contains genes encoding holin, lysin A, and lysin B involved in host cell lysis. The one-step growth curve demonstrated that KVT1 has a latency time of 90 min and an average burst size of 101 phage particles per infected cell. It can withstand a temperature of up to 45°C and has a maximum viability between pH 8 and 9. Some mycobacteriophages from cluster K are known to infect the pathogenic (); hence, KVT1 holds potential for the phage therapy against tuberculosis, and it can also be engineered to convert into an exclusively lytic phage.
分枝杆菌噬菌体是感染 属成员的病毒。由于分枝杆菌病（如肺结核）中抗生素耐药性的增加，分枝杆菌噬菌体作为替代治疗剂重新受到关注。分枝杆菌噬菌体高度多样化，根据它们的基因组序列，它们被分为 30 个聚类和 10 个单倍体。在本文中，我们描述了一种新型分枝杆菌噬菌体 Kashi-VT1（KVT1）的分离和特性，该噬菌体感染 mc 155（）并从印度瓦拉纳西分离出来。KVT1 是一种聚类 K1 的温和噬菌体，在透射电子显微镜下观察到属于 家族。噬菌体基因组长 61,010 个碱基对，GC 含量为 66.5%，编码 101 个推定的开放阅读框。KVT1 基因组编码免疫抑制剂、酪氨酸整合酶和外切酶，这是温和噬菌体的特征。它还包含编码参与宿主细胞裂解的 holin、lysin A 和 lysin B 的基因。一步生长曲线表明，KVT1 的潜伏期为 90 分钟，平均每个感染细胞释放 101 个噬菌体颗粒。它可以承受高达 45°C 的温度，在 pH8 到 9 之间具有最大的生存能力。一些聚类 K 的分枝杆菌噬菌体已知感染致病性 （）；因此，KVT1 具有用于结核病噬菌体治疗的潜力，并且可以被工程改造为专门的裂解噬菌体。
