A One Health Perspective: Occurrence Study of Carbapenem-Resistant Bacteria and Other Emerging Pathogens from Recycled Wastewater Used in Agriculture

Recycled wastewater is vital for the circular economy, especially on water-scarce islands. This study explored the presence of Carbapenem-Resistant Enterobacterales and other emerging pathogens in irrigation water on four Canarian Islands, applying a One Health perspective. Using membrane filtration and MALDI-TOF mass spectrometry, 69 bacterial isolates were identified. The findings revealed that 78% were Gram-negative bacilli like <i>Pseudomonas aeruginosa</i>, <i>Acinetobacter</i> spp., Enterobacteriaceae, etc., while 22% were Gram-positive bacteria, including <i>Enterococcus</i> spp. The main mechanisms of carbapenem resistance in <i>Pseudomonas</i> spp. and <i>Acinetobacter</i> spp. were oxacillinases, followed by metallo-β-lactamases (MBL). In Enterobacteriaceae, characterization of carbapenemase types was less frequent, with oxacillinase 48 (OXA-48) being the most prevalent. The detection of multidrug-resistant organisms in recycled wastewater highlights an urgent need for routine microbiological monitoring in water management to protect both public health and agricultural sustainability.