Epidemiology, resistance genomics and susceptibility of species: results from the 2020 Spanish nationwide surveillance study.

BackgroundAs increasing antibiotic resistance in poses a global healthcare challenge, understanding its evolution is crucial for effective control strategies.AimWe aimed to evaluate the epidemiology, antimicrobial susceptibility and main resistance mechanisms of spp. in Spain in 2020, and to explore temporal trends of .MethodsWe collected 199 single-patient spp. clinical isolates in 2020 from 18 Spanish tertiary hospitals. Minimum inhibitory concentrations (MICs) for nine antimicrobials were determined. Short-read sequencing was performed for all isolates, and targeted long-read sequencing for . Resistance mechanisms, phylogenetics and clonality were assessed. Findings on resistance rates and infection types were compared with data from 2000 and 2010.ResultsCefiderocol and colistin exhibited the highest activity against , although colistin susceptibility has significantly declined over 2 decades. non- strains were highly susceptible to most tested antibiotics. Of the isolates, 47.5% (56/118) were multidrug-resistant (MDR). Phylogeny and clonal relationship analysis of revealed five prevalent international clones, notably IC2 (ST2, n = 52; ST745, n = 4) and IC1 (ST1, n = 14), and some episodes of clonal dissemination. Genes , and were identified in 49 (41.5%), eight (6.8%) and one (0.8%) isolates, respectively. IS1 was found upstream of the gene (a -like in 10 isolates.ConclusionsThe emergence of OXA-23-producing ST1 and ST2, the predominant MDR lineages, shows a pivotal shift in carbapenem-resistant (CRAB) epidemiology in Spain. Coupled with increased colistin resistance, these changes underscore notable alterations in regional antimicrobial resistance dynamics.