Vancomycin-Resistant Enterococcus in Wild Animals: A Global Scoping Review.

Abstract

Antimicrobial resistance is a global One Health concern, and vancomycin-resistant Enterococcus (VRE) remains one of the clinically important resistant bacterial groups. Although VRE has been extensively studied in clinical and livestock settings, it has been investigated far less often in free-ranging wild animals. This scoping review maps the published evidence on VRE in wild animals, with emphasis on reported prevalence, host and environmental correlates, anthropogenic exposures, and laboratory detection methods rather than quantifying pooled effect sizes. A structured search of PubMed, ScienceDirect, Scopus, Web of Science, and Google Scholar was conducted from database inception to the final search stage used for this review, with only peer-reviewed English-language primary studies contributing empirical wildlife VRE data included in the synthesis. Eligibility was guided by the Population-Concept-Context framework, and the mapped evidence included mammals plus one reptile study retained in the review scope. Twenty-five studies met the inclusion criteria. Most were conducted in Europe, with substantially fewer studies from Africa and South America, indicating major geographical gaps. Reported prevalence ranged from 1.08% in feral pigs in Brazil to 100% in wild rabbits in Spain, although several striking estimates were based on very small samples and should be interpreted cautiously. Culture-based methods were most frequently used, whereas PCR-based approaches were particularly useful for confirming resistance genes. Overall, the evidence suggests that wild animals can act as reservoirs or sentinels of VRE exposure in anthropogenically influenced environments. Standardized surveillance, clearer reporting, and broader One Health monitoring that explicitly includes wildlife are needed.