Engineered bacteriophages for therapeutic and diagnostic applications.

Antimicrobial resistance represents one of the most serious threats to both public health and economic sustainability. One of the promising approaches to address this problem is phage therapy - treatment of pathogenic bacterial infections using bacteriophages. Bacteriophages have a narrow host spectrum of activity, minimal side effects and self-replication at the infection site, which positions them as promising candidates to complement or replace conventional antibiotics. Moreover, they can be easily genetically modified to enhance their effectiveness and safety. In this At a Glance article, we highlight the timely relevance of engineered phages as an innovative solution in a rapidly evolving healthcare landscape. First, we introduce bacteriophages' life cycle, ecology and therapeutic history, emphasizing their role in One Health strategies. Then, we describe advanced engineering techniques that can be used to expand bacteriophages' functionalities. Finally, we discuss innovative applications of engineered bacteriophages in biotechnological applications and as a potential countermeasure for antimicrobial resistance, including serving as a shuttle for delivering genes and drugs to the targeted bacterial and eukaryotic cells, targeting intracellular bacteria, contributing to vaccine development, facilitating advancements in tissue engineering and improving bacteriophages' antibacterial properties.