Phages possess the ability to selectively eliminate pathogenic bacteria by recognizing bacterial surface receptors. Since their discovery, phages have been recognized for their potent bactericidal properties, making them a promising alternative to antibiotics in the context of rising antibiotic resistance. However, the rapid emergence of phage-resistant strains (generally involving temperature phage) and the limited host range of most phage strains have hindered their antibacterial efficacy, impeding their full potential. In recent years, advancements in genetic engineering and biosynthesis technology have facilitated the precise engineering of phages, thereby unleashing their potential as a novel source of antibacterial agents. In this review, we present a comprehensive overview of the diverse strategies employed for phage genetic engineering, as well as discuss their benefits and drawbacks in terms of bactericidal effect.

In this study, we conducted the morphological observation, biological and genomic characterization, evolutionary analysis, comparative genomics description, and proteome identification of a recently isolated mycobacteriophage, WIVsmall. Morphologically, WIVsmall is classified as a member of the Siphoviridae family, characterized by a flexible tail, measuring approximately 212 nm in length. The double-stranded phage genome DNA of WIVsmall spans 53,359 base pairs, and exhibits a G + C content of 61.01%. The genome of WIVsmall comprises 103 protein-coding genes, while no tRNA genes were detected. The genome annotation unveiled the presence of functional gene clusters responsible for mycobacteriophage assembly and maturation, replication, cell lysis, and functional protein synthesis. Based on the analysis of the phylogenetic tree, the genome of WIVsmall was classified as belonging to subgroup F1. A comparative genomics analysis indicated that the WIVsmall genome exhibited the highest similarity to the phage SG4, with a percentage of 64%. The single-step growth curve analysis of WIVsmall revealed a latent period of 120 min, and an outbreak period of 200 min.