Temporal evolution of antimicrobial resistance: insights from a decade-long surveillance of Klebsiella pneumoniae infections in the Comunitat Valenciana (Spain)

Background Klebsiella pneumoniae is a highly prevalent antimicrobial-resistant (AMR) pathogen in healthcare-settings worldwide, especially third-generation cephalosporin (3GC) and carbapenem-resistant strains. In the Comunitat Valenciana, Spain, these strains are a growing concern due to their increasing prevalence and limited treatment options. Fortunately, the Comunitat Valenciana has a well-established microbiological surveillance system, called RedMIVA, that gathers all tests performed at microbiology laboratories across the region, providing invaluable data for understanding resistance epidemiology. Methods We analyzed all K. pneumoniae test results from the RedMIVA between 2010 and 2022. We curated the susceptibility profiles, identified the total episodes attributable to C3G or carbapenem-resistant strains, and compared their relative abundance across time and hospitals. Additionally, we evaluated potential risk factors associated with the acquisition of resistant strains. Results Among the 131,159 identified cases, 23.7% were attributable to 3GC, or carbapenem-resistant isolates. 3GC-resistance was already prevalent (~ 12%) in the region at the start of the study (2010), whereas carbapenem-resistance emerged in 2016, with both showing differences in prevalence among hospitals. Notably, the initial rise of carbapenem resistance occurred in large hospitals, but by 2020, cases started to rise in smaller healthcare settings. Finally, we found that the elderly and male gender were risk factors for developing resistant infections, and that such episodes were associated with a higher hospitalization rate in the region. Conclusions This study demonstrates the power of comprehensive surveillance data to unravel the dynamics of AMR pathogens regionally. Our findings describe the overall prevalence of 3GC- and carbapenem resistant rates regionally and in each hospital, enhancing the development of effective control strategies. Notably, we describe the concerning spread of carbapenem resistance from larger hospitals to smaller settings. This critical finding highlights the urgent need for further research to elucidate the mechanisms behind this shift and develop effective strategies to prevent community transmission.