Genesis Apeh

Nigeria

Phage Engineering: A Next-Gen Solution to Antibiotic-Resistant Infectious Diseases

Genesis Apeh [1] , Chinedum Mgbemena [2]

1Department of Biochemistry, University of Nigeria Nsukka, Enugu state Nigeria
2Faculty of Pharmaceutical sciences, University of Nigeria Nsukka, Enugu state Nigeria

Abstract

Background

The rise of antimicrobial resistance (AMR) and persistence of intracellular infections such as Salmonella enterica and Mycobacterium tuberculosis have created a global treatment gap. Conventional antibiotics poorly penetrate mammalian cells, leaving intracellular bacteria unharmed and leading to recurrent infections. Bacteriophages, viruses that infect bacteria, are now being engineered to overcome this limitation. Leveraging synthetic biology, these natural bacterial predators can be transformed into programmable, cell-invasive nanomachines capable of eradicating pathogens hiding within mammalian cells.
This review examines and synthesizes current evidence on phage engineering strategies that enable mammalian cell invasion, focusing on representative studies involving three model phages with distinct infection mechanisms, eliminating intracellular bacterial infections, offering a novel preventive and therapeutic model against infectious diseases.

Methods

A systematic review of peer-reviewed literature published between 2010 and 2024 was conducted using PubMed, Scopus, and ScienceDirect databases. Articles were screened for reports on engineered or naturally internalized phages with demonstrated or proposed mammalian cell interactions. Three model phages – M13, T4, and E. Coli K1F – were observed, genetically modified using CRISPR-Cas9 and molecular cloning techniques. Their capsid and tail proteins were fused with cell-penetrating peptides (CPPs) and epidermal growth factor (EGF) ligands to promote receptor-mediated entry. Phages were further engineered to deliver antimicrobial peptides and CRISPR-Cas systems targeting essential intracellular bacterial genes. Uptake and bacterial clearance were analysed in macrophage and epithelial infection models via fluorescence microscopy, qPCR, and CFU assays.

Results

Reviewed studies revealed that engineered phages exhibited a 3.2-fold increase in mammalian cell uptake and over 85% intracellular bacterial clearance compared to wild-type strains. EGF-K1F phages avoided phagocytic degradation and reduced intracellular E. Coli K1 by 92% within 12 hours, while CRISPR-loaded M13 phages achieved 80–90% gene disruption in Salmonella-infected cells. Combined with low-dose antibiotics, this therapy produced a synergistic bactericidal effect (FIC index = 0.38) and delayed resistance development.

Conclusions

The reviewed evidence underscores that engineering bacteriophages to invade mammalian cells represents a groundbreaking approach to combating intracellular and drug-resistant infections. By merging virology, synthetic biology, and precision medicine, this study presents a future-forward strategy for preventive infectious disease management and the global AMR crisis.