Phage Therapy in Combating Multidrug-Resistant Gram-Negative Pathogens: A Scoping Review.

Area of Science:

• * Microbiology
• * Infectious Diseases
• * Pharmacology

Background:

• * Rising threat of multidrug-resistant (MDR) Gram-negative pathogens: Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Helicobacter pylori.
• * Urgent need for novel therapeutic alternatives to combat these resistant infections.

Purpose of the Study:

• * To review current evidence on the efficacy of lytic bacteriophages against critical MDR Gram-negative pathogens.
• * To identify research gaps and challenges in the implementation of phage therapy.

Main Methods:

• * Scoping review of literature from 2015-2025, searching PubMed, Web of Science, and Scopus AI.
• * Inclusion of experimental and human studies on phage therapy for MDR, extensively drug-resistant (XDR), or pan-drug-resistant (PDR) strains.
• * Analysis of 172 selected articles.

Main Results:

• * Increasing research trend from 2015-2025, predominantly on K. pneumoniae, P. aeruginosa, and A. baumannii.
• * No eligible studies found for MDR H. pylori.
• * All studies confirmed lytic activity; phage cocktails were superior to single phages in some cases.
• * Demonstrated antibiofilm activity and successful bacterial reduction in animal models.
• * 87.5% of human case studies reported patient improvement or infection clearance.

Conclusions:

• * Lytic bacteriophages present a strong potential as a novel therapeutic strategy.
• * Significant challenges remain: lack of data for MDR H. pylori, heterogeneity in animal models, and limited large-scale human trials.
• * Future research should focus on standardization, mechanistic studies, and robust clinical trials for regulatory acceptance.