Table 1.

Key biological aspects in phage–bacterium interaction that may affect clinical outcomes.

Biological mechanism	Biological role	Desired properties for therapy	Implications for therapy	Focus for improvement of clinical outcomes
Phage attachment	Infectivity (lytic activity)	High lytic activity: large burst size	Dosing and timing of administration	Diverse banks of characterized phages; genome engineering
Receptor specificity	Infectivity (lytic activity; host range)	Defined host range	Targeting; clinical spectrum of activity (target bacteria); resistance	Personalized therapy; curated phage/bacteria banks; AI/machine learning approaches; phage cocktails; phage “training”; genome engineering
Phage life cycle	Infectivity (lytic activity); transduction	High lytic activity; low transduction rates	Bacterial killing efficiency; transmission of virulence/resistance	Phage genomics; curated phage banks; genome engineering
Bacterial cell physiological state/ density	Niche colonization and invasion	High lytic activity; high penetration	Dosing and timing of administration; phage/antibiotic synergy; target diseases	Smart delivery
Bacterial lifestyle	Communal (biofilms); intracellular	High penetration	Penetration (target availability); clinical spectrum of activity (type of disease)	Smart delivery
Co‐adaptation	Microbial evolution	Poor ability to elicit resistance; stable high infectivity	Resistance development	Phage–phage and phage–antibiotic synergy