Characterization of antibiotic resistance of isolates of Klebsiella pneumoniae causing health care-associated infections (HAIs) in hospitals in the Department of Nariño.

Introduction: Klebsiella pneumoniae is a critical priority pathogen that causes healthcare-associated infections (HAIs). The bacterium demonstrates intrinsic or acquired antimicrobial resistance (AMR). Objective: The resistance and genomic variability of K.pneumoniae in HAIs in the Department of Nariño (2021-2023) were analyzed. Methodology: 44 isolates were identified at the 16S rRNA gene level, which were evaluated for resistance to 13 antibiotics. Genetic variability was determined by in silico restriction enzyme cutting and with the BOX-A1R-based repetitive extragenic palindromic-PCR (BOX-PCR) and Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR) markers. Subsequently, a presence-absence matrix was constructed using resistance data, microbiological data, and origin of infection. A dendrogram was constructed using the dice similarity coefficient. Results: 44 isolates were identified as K.pneumoniae (% identity>97%, e≈0, coverage>96%), 95% of these presented multidrug resistance, >80% were resistant to fluoroquinolones, beta-lactams and combination antibiotics. High genomic variability and a higher frequency of isolates from ICUs and blood samples were demonstrated; coinfection with COVID was observed in 20% of the samples. Conclusion: There is marked AMR and genomic variability among K.pneumoniae. This study corroborates the alarming challenges that public health may face due to AMR and reinforces the need to promote the implementation of a robust epidemiological surveillance system in the region to inform treatment decisions, guide policy recommendations, and assess the impact of resistance containment interventions.