The present and the future of antimicrobial resistance surveillance in Catalonia (Spain), 2024: from manual to...

Antimicrobial resistance (AMR) remains a major global public health concern requiring coordinated surveillance and technological innovation. In Catalonia, AMR surveillance is conducted through the Microbiological Reporting System of Catalonia (MRSC) and will be integrated into the Epidemiological Surveillance Information System (SIVEC), enabling automated and real-time monitoring. This study aimed to evaluate the current landscape of AMR surveillance and laboratory capacity across clinical microbiology laboratories (CMLs).

All CMLs participating in the MRSC were invited to complete a structured survey assessing diagnostic capacity, resistance mechanism (RM) detection, laboratory information systems (LIS), and reporting practices. Surveillance data from invasive isolates (one per patient and episode) collected between 2016 and 2023 were analysed. CMLs were classified by complexity (L1-L3) according to phenotypic, molecular and genomic capabilities. Temporal trends in resistance were assessed using logistic regression models.

By 2023, 53 CMLs participated compared with 28 in 2016, reflecting a marked increase in coverage. A total of 87,556 invasive isolates and 694,289 susceptibility tests were reported. Escherichia coli was the most frequently notified microorganism (37,999 isolates), followed by Klebsiella pneumoniae (12,626) and methicillin-susceptible Staphylococcus aureus (10,464). All laboratories followed EUCAST criteria, although only 56.6% had implemented the 2023 version. Most CMLs (92.5%) detected RMs and 73.6% monitored multidrug resistance. Based on complexity, 18.9% were L1, 66.0% L2, and 15.1% L3; most notifications were reported by L2 (57.4%) and L3 laboratories (39.4%). Carbapenem resistance decreased in Pseudomonas aeruginosa (21.7 to 12.9%) and K. pneumoniae (6.3% to 3.2%), whereas E. coli increased (0.07 to 0.52%). Vancomycin resistance increased in Enterococcus faecium (0.27 to 2.30%) and remained low in E. faecalis. Third-generation cephalosporin resistance increased in E. coli (14.4 to 17.8%) and decreased in K. pneumoniae (36.0 to 26.6%), while MRSA declined (33.1 to 20.6%).

AMR surveillance in Catalonia provides robust and representative data across a heterogeneous network. Further efforts are needed to ensure consistent EUCAST implementation and expand RM detection. The implementation of SIVEC will enable integrated, real-time surveillance and support timely, evidence-based public health decision-making.