Monitoring antimicrobial resistance trends and emerging carbapenemases in Enterobacterales causing companion animal infections: a four-year study

A Portuguese surveillance study analyzed 4,155 Enterobacterales isolates from companion animal infections (2020–2023) to track antimicrobial resistance (AMR) trends and identify carbapenemase-producing Enterobacterales (CPE). Klebsiella and Enterobacter species showed significantly higher resistance levels than E. coli. Most resistance patterns remained stable or declined over time, although fluoroquinolone resistance increased toward the end of the study period. The researchers detected 18 CPE strains carrying major carbapenemase genes (e.g., blaKPC-3, blaNDM-5, blaOXA variants) linked to globally disseminated high-risk clones. Genomic analysis suggested possible recent transmission events between unrelated cases. The findings highlight that companion animals can harbor and potentially spread clinically important AMR pathogens, underscoring the need to include pets in One Health surveillance and stewardship efforts.