Antimicrobial resistance prevalence in clinical and aquatic environmental ESKAPE: a systematic review with meta-analysis

Antimicrobial resistance (AMR) in ESKAPE pathogens represents a major global health threat. Although these organisms are well established as causes of healthcare-associated infections, aquatic environments may function as reservoirs and transmission pathways for resistance. This systematic review aimed to estimate the prevalence of AMR in ESKAPE pathogens isolated from water and wastewater and to compare resistance patterns with those observed in human clinical isolates. The review followed PRISMA guidelines and was registered in PROSPERO (CRD420251020930). PubMed, Embase, and the Cochrane Library were searched to January 14, 2025. Eligible studies were original research reporting antimicrobial susceptibility data for ESKAPE pathogens isolated from both aquatic environmental matrices and clinical samples. Pooled resistance prevalence was estimated using generalized linear mixed models, with heterogeneity assessed using {tau}{superscript 2} and I{superscript 2} statistics and small-study effects evaluated by funnel plots and Eggers test. Of 304 records identified, 18 studies met the inclusion criteria. The pooled overall resistance prevalence was 0.46 (95% CI: 0.36-0.57), with heterogeneity (I{superscript 2} = 98.8%). Resistance was higher in clinical isolates (0.67; 95% CI: 0.55-0.77) than in environmental isolates (0.24; 95% CI: 0.14-0.39), and environmental resistance was greater in effluent-impacted waters than in non-effluent sources. Interpretation is limited by methodological heterogeneity, selective isolation approaches in environmental studies, and imprecision due to small and unevenly distributed samples. Overall, AMR in ESKAPE pathogens remains more prevalent in clinical settings, but aquatic environments, particularly wastewater, represent resistance reservoirs, underscoring the need for standardized methodologies within a One Health framework. Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/view/CRD420251020930, CRD420251020930 HighlightsAntimicrobial resistance was higher in clinical isolates than in aquatic isolates. Resistance patterns showed extreme heterogeneity across studies. Effluent-impacted waters showed higher resistance than non-effluent sources. Higher environmental resistance in some classes reflected methodological artifacts.