Wildlife as sentinel of antimicrobial resistance in Klebsiella spp. with genomic insights into Klebsiella pneumoniae in Northern Italy.

INTRODUCTION

Antimicrobial resistance (AMR) is a global concern, particularly worsened by the spread of multidrug-resistant (MDR) bacteria such as Klebsiella pneumoniae.

METHODS

This study investigated the presence of extended-spectrum β-lactamase (ESBL) and carbapenemase-producing K. pneumoniae in wild birds (corvids and waterfowl) and in red foxes in Northern Italy.

RESULTS AND DISCUSSION: Although the overall prevalence of K. pneumoniae in the present study was relatively low (2.0, 95% CI: 1.0-3.7%), its isolation from multiple wild species confirms the environmental circulation of this clinically relevant AMR bacterium in ecosystems not directly exposed to antibiotic pressure. In particular, the isolation of a carbapenemase-producing strain from a fox highlights the introduction of clinically significant carbapenemase genes into wildlife reservoirs. The phenotypic AMR profiles of K. pneumoniae isolates revealed a high prevalence of MDR strains that were largely confirmed by the genomic analysis. In-silico analyses of K. pneumoniae sequencing data led to the identification of the most frequent resistance genes and the in-silico typing reveals the prevalence of the ST307 high-risk clone. Remarkably, wildlife could be considered a significant AMR sentinel, serving as carriers of MDR K. pneumoniae in different and even distant geographic areas. These findings underscore the importance of integrating wildlife surveillance to monitor the environmental spread of AMR within a One Health approach.