Clinical characteristics, risk factors, and clinical outcomes of hospitalized patients with Stenotrophomonas maltophilia bacteremia at Imam Reza Hospital, Mashhad, during 2021–2022

Document Type : Original article

Authors

1 Associate Professor of Infectious Diseases and Tropical Medicine, Faculty of Medicine, Department of Infectious Diseases, Mashhad University of Medical Sciences, Mashhad, Iran.

2 Professor of Infectious Diseases and Tropical Medicine, Faculty of Medicine, Department of Infectious Diseases, Mashhad University of Medical Sciences, Mashhad, Iran

3 Infectious Diseases Specialist, Faculty of Medicine, Department of Infectious Diseases, Mashhad University of Medical Sciences, Mashhad, Iran.

10.22038/nnj.2026.94411.1541

Abstract

Background and Aims: Stenotrophomonas maltophilia, an opportunistic, intrinsically multidrug-resistant Gram-negative bacillus, is an emerging and lethal pathogen in hospital settings. This study aimed to detemine clinical characteristics, risk factors, and outcomes of patients with S. maltophilia bacteremia at Imam Reza Hospital, Mashhad, Iran (2021–2022).
Materials and Methods: In this retrospective study, demographic data, underlying diseases, clinical findings, antibiotic susceptibility patterns, and clinical outcomes of 100 patients with S. maltophilia-positive blood cultures were extracted and analyzed using SPSS software version 26. Statistical analysis was performed using Chi-square, Fisher’s exact, t-test, and Mann–Whitney tests (significance level set at p < 0.05).
Results: The mean age of the patients was 50.78 ± 18.89 years, and 57 (57%) were male. The most common underlying conditions were diabetes (28%), malignancy (19%), chronic wounds (18%), and renal disease (15%). Fever and leukocytosis (45%) were common clinical findings. The highest antibiotic susceptibility was observed for fluoroquinolones (67%) and sulfonamides (44%), while the highest resistance was noted against cephalosporins and carbapenems. The mortality rate was 12.2%. Organ transplantation (P=0.027), tachypnea (P=0.002), and thrombocytopenia (P=0.007) were significantly associated with an increased risk of mortality.
Conclusion: Stenotrophomonas maltophilia bacteremia primarily occurs in patients with underlying risk factors and is associated with significant mortality. Extensive resistance to beta-lactams and carbapenems, alongside relative susceptibility to fluoroquinolones and co-trimoxazole, was confirmed. Therefore, rational antibiotic use and early identification of high-risk patients are essential to improve clinical outcomes.

Keywords

References

 

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Navid No
Volume 29, Issue 97
June 2026
Pages 21-33

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