Clinical Outcomes associated with Multidrug-Resistant Gram-Negative Bacterial Infections in Chronic Wound Infections: an Umbrella Review and Meta-analysis

Chronic wound infections caused by multidrug-resistant gram-negative bacteria (MDR-GNB), particularly carbapenem-resistant Enterobacterales (CRE), extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E), carbapenem-resistant Acinetobacter baumannii (CRAB), and multidrug-resistant Pseudomonas aeruginosa (MDR-PsA), represent a major clinical challenge.This umbrella review aimed to evaluate the quality of evidence and estimate infection and mortality rates following colonization with these pathogens in chronic wound patients.An umbrella review and meta-analysis were conducted using PubMed, Scopus, Web of Science, and Cochrane databases up to August 2025.Systematic reviews and meta-analyses reporting colonization and infection by CRE, ESBL-E, CRAB, or MDR-PsA in chronic wounds were included.Study quality was assessed with AMSTAR 2, and pooled infection proportions were analyzed using Jamovi statistical software (version 2.3.28) with a random-effects model.Twenty-three reviews comprising more than 60,000 isolates were analyzed.Most studies were of low to critically low quality.The pooled incidence of infection following colonization was 23% (95% CI: 0.11-0.35)for ESBL-E and 54% (95% CI: 0.28-0.81)for MDR-PsA, while CRAB and CRE showed higher rates approaching 90%.Mortality among infected patients ranged from 66% to 91%.Despite high heterogeneity, a consistent association between colonization and subsequent infection was observed.Colonization with CRE, ESBL-E, CRAB, and MDR-PsA markedly increases the risk of infection and death in chronic wound patients.These findings underscore the urgent need for standardized definitions, stronger infection control, and innovative therapeutic strategies to reduce the MDR-GNB burden.