Evolving strategies of intracellular Hypervirulent Klebsiella pneumoniae during phage therapy: Reducing host autophagy and inflammation.

Hypervirulent Klebsiella pneumoniae (hvKp) presents challenges in infection management due to antibiotic resistance associated with its intracellular persistence. This study investigates the efficacy of phage therapy against intracellular hvKp using a two-stage murine model. We assessed changes in virulence, host survival, and immune responses through phagocytosis assays, transmission electron microscopy, and Western blotting, complemented by transcriptomic and proteomic analyses. Results indicate that phage therapy reduces mortality and modulates bacterial virulence by downregulating capsule production. Following phage exposure, hvKp adapts by enhancing its oxidative stress resistance. Crucially, these adaptations weaken host inflammatory and autophagy responses, enabling better survival within host cells. These adaptations suggest that while phage therapy can mitigate infection severity, the capacity of hvKp to modulate host pathways underscores the complexity of treating intracellular infections and highlights the importance of targeting both bacterial and cellular responses.