West Asia Organization for Cancer Prevention (WAOCP), APOCP's West Asia Chapter. Asian Pacific Journal of Cancer Prevention 1513-7368 25 10 2024 10 01 Cytotoxic Effect of Stenotrophomonas maltophilia Isolated from Prostate and Bladder Cancer Patients in Iraq 3701 3705 91373 10.31557/APJCP.2024.25.10.3701 EN Enas Ammar Alnukhba University Collage, Medical Laboratory Department, Baghdad, Iraq. Nada Al-Mudallal Al-Iraqia University, College of Medicine, Medical Microbiology Department, Baghdad, Iraq. Sura Mouaid Abbas Department of Biology, College of Science, Al-Mustansiriyah university, Baghdad, Iraq. 0000-0001-5132-0504 Journal Article 2024 06 16 Objective: This study investigated the cytotoxic effects of Stenotrophomonas maltophilia on normal human cells. Methods: Seven isolates of S. maltophilia were obtained from 120 urine samples collected from prostate and bladder cancer patients, with diagnoses confirmed via Vitek. The cytotoxicity of these bacterial isolates was assessed on normal human fibrocyte cells (NHF) using various concentrations of bacterial filtrate (3.125, 6.25, 12.5, 25, 50, and 100 μg/ml). Results: The bacterial filtrate exhibited significant toxicity to NHF cells, with the highest cell death rate of 68% and the lowest optical density (OD) of 0.25 at a concentration of 100 μg/ml. The IC50 value, indicating the concentration at which 50% inhibition of cell viability occurred, was determined to be 49.35 μg/ml. Further research is necessary to explore the potential role of these bacterial isolates in promoting cancer through inflammation. Conclusion: The clinical isolates of S. maltophilia demonstrated substantial cytotoxic activity against normal human fibrocyte cells, leading to a notable reduction in both cell number and optical density, with the highest percentage of cell death observed. These findings suggest the need for further investigation into the specific toxins or enzymes involved, which could pave the way for future studies. https://journal.waocp.org/article_91373_5c89274565f842be38621a8d3a70da86.pdf