Title : Stenotrophomonas maltophilia endocarditis: A notorious pathogen with a rare presentation

Abstract:

Background:
Stenotrophomonas maltophilia is an emerging multidrug-resistant gram-negative bacillus associated with serious infections, particularly in immunocompromised hosts. Infective endocarditis due to S. maltophilia remains exceedingly rare and challenging to treat due to its intrinsic resistance and lack of consensus guidelines.

Case Presentation:
We report a case of a 32-year-old female with end-stage renal disease on maintenance hemodialysis via permcath who presented with fever, altered sensorium, and respiratory distress. Imaging revealed splenic and cerebral infarcts, and transthoracic echocardiogram demonstrated vegetations on the mitral and aortic valves. Blood cultures consistently grew S. maltophilia, sensitive to co-trimoxazole, levofloxacin, and minocycline. The permcath was promptly removed. The patient initially received ceftriaxone and vancomycin empirically, later transitioned to targeted therapy with co-trimoxazole and levofloxacin. Cytopenias led to substitution with minocycline. The patient improved clinically and biochemically without requiring valve surgery and completed six weeks of tailored antibiotic therapy.

Discussion:
S. maltophilia endocarditis, though rare, is associated with significant morbidity and mortality. Risk factors include hemodialysis, indwelling catheters, and immunosuppression. This case emphasizes the need for early recognition, catheter removal, and culture-guided therapy. Combination antibiotic therapy may be necessary in moderate to severe cases.

Conclusion:
This case highlights the diagnostic and therapeutic challenges of S. maltophilia endocarditis. A high index of suspicion in at-risk populations, prompt culture-based diagnosis, and individualized antibiotic selection are critical to favorable outcomes.