en Diagnostic/screening methods and protocols Diagnostic/screening methods and protocols Original article Original article <div style="text-align: justify;"><b><span style="font-size:10.0pt"><span style="line-height:107%"><span new="" roman="" style="font-family:" times="">Introduction</span></span></span></b><span style="font-size:10.0pt"><span style="line-height:107%"><span new="" roman="" style="font-family:" times="">: <i>Stenotrophomonas maltophilia</i> 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 <i>S. maltophilia</i> respiratory infections among cancer patients at a large hospital, aiming to describe the clinical and microbiological characteristics of these cases. <b>Methods</b>: We investigated cancer patients presenting with respiratory symptoms between February 1^st and February 28^th, 2023 in ten of whom <i>S. maltophilia</i> 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&reg; 2 system (BioM&eacute;rieux). Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method. <b>Results</b>: Ten adult cancer patients (6 females, 4 males) developed <i>S. maltophilia</i> pneumonia between February 1^st and February 28^th, 2023. Eight patients had hematological malignancies, and two had solid tumors. All patients&#39; infections were susceptible to treatment with trimethoprim-sulfamethoxazole, and all patients recovered fully following treatment. <b>Conclusion:</b> We identified a cluster of <i>S. maltophilia</i> 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 <i>S. maltophilia</i> infections in cancer patients, enabling timely, susceptibility-guided antimicrobial therapy.</span></span></span></div> Cancer patients, Immunocompromised, Non-fermenting Gram-negative bacilli, Respiratory infections, Sporadic, Stenotrophomonas maltophilia 50 56 http://jommid.pasteur.ac.ir/browse.php?a_code=A-10-472-1&slc_lang=en&sid=1 Mahua Sinha mahuasinha@gmail.com 0000-0002-4155-817X No Department of Microbiology, Kidwai Memorial Institute of Oncology, Bengaluru, India Sumathi BG iimationsumathi@gmail.com 0009-0000-5083-5346 Yes Department of Microbiology, Kidwai Memorial Institute of Oncology, Bengaluru, India Priyanka Shivashankar priyavij2202@gmail.com 0009-0006-0868-8526 No Department of Microbiology, Kidwai Memorial Institute of Oncology, Bengaluru, India Junia Joseph juniajoseph22@gmail.com 0009-0003-2302-6449 No Department of Microbiology, Kidwai Memorial Institute of Oncology, Bengaluru, India Sahana Shetty sahanashettyns@gmail.com 0009-0003-5283-2669 No Department of Microbiology, Kidwai Memorial Institute of Oncology, Bengaluru, India