Klebsiella pneumoniae is a Gram-negative bacterium capable of causing severe infections, particularly in hospital settings. Although it is part of the normal microbiota, its dissemination and antibiotic resistance represent major challenges for treatment and public health. The increasing resistance to antimicrobials, especially carbapenems, poses significant difficulties in clinical practice. This study aimed to analyze the prevalence and carbapenem resistance profile of K. pneumoniae isolates from a clinical laboratory in Concórdia, Santa Catarina (SC), emphasizing cases in non-hospitalized patients.

A retrospective analysis was performed on 1,932 positive bacterial cultures (2023–2024) from a clinical laboratory in Concórdia (SC). Identification of K. pneumoniae was conducted using standard microbiological methods. Carbapenem susceptibility (ertapenem, meropenem, imipenem) was assessed by disk diffusion, with confirmation by MIC testing when indicated, following BrCAST 2023 criteria. Qualitative or quantitative cultures were used depending on sample type. Confidence intervals were calculated using the Wilson method.

Among the 1,932 bacterial cultures analyzed, 217 (11.2%; 95% CI 9.8–12.7%) were identified as K. pneumoniae, consistent with national estimates (10–15%). Of these, 13 isolates (6.0%; 95% CI 3.2–9.9%) exhibited carbapenem resistance, all from outpatient samples, suggesting potential community dissemination of this resistance mechanism.

The data highlight an alarming emergence of carbapenem-resistant K. pneumoniae among ambulatory patients, indicating probable community spread. This phenomenon underscores the urgent need for continuous surveillance and integrated infection-control strategies to preserve antimicrobial effectiveness and safeguard public health. A multidisciplinary approach is essential to mitigate the propagation of resistance and ensure effective therapeutic options for infections caused by this pathogen.