Sporadic Stenotrophomonas maltophilia Respiratory Infections in Cancer Patients

Introduction:Stenotrophomonas maltophilia is a bacterium that increasingly causes respiratory and bloodstream infections, particularly in individuals with compromised immune systems, such as cancer patients.This study investigates a series of S. maltophilia respiratory infections among cancer patients at a large hospital, aiming to describe the clinical and microbiological characteristics of these cases.Methods: We investigated cancer patients presenting with respiratory symptoms between February 1 st and February 28 th , 2023 in ten of whom S. maltophilia isolates were recovered from clinical specimens through microbiological culture.Identification was initially based on colony morphology, oxidase reaction, glucose fermentation, motility, and other biochemical tests, followed by confirmation using the Vitek 2 system (BioMrieux).Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method.Results: Ten adult cancer patients (6 females, 4 males) developed S. maltophilia pneumonia between February 1 st and February 28 th , 2023.Eight patients had hematological malignancies, and two had solid tumors.All patients' infections were susceptible to treatment with trimethoprimsulfamethoxazole, and all patients recovered fully following treatment. Conclusion:We identified a cluster of S. maltophilia respiratory infections, but it did not meet the criteria for a true outbreak due to the lack of a common source and evidence of transmission between patients.Despite reinforced infection control measures, limitations in surveillance hindered identifying the source and implementing prevention strategies.This cluster emphasizes the need for vigilance in recognizing S. maltophilia infections in cancer patients, enabling timely, susceptibility-guided antimicrobial therapy.2025 Vol. 13 No. 1 primarily with trimethoprim-sulfamethoxazole, is essential for patients with weakened immune systems.This study aims to analyze the clinical, microbiological, and epidemiological characteristics of a cluster of sporadic S. maltophilia respiratory infections in cancer patients over a short span of one month at our institution.