Eur J Clin Microbiol Infect Dis (1998) 17:353-356 9 Springer-Verlag 1998 Note Infective Endocarditis due to Stenotrophomonas (Xanthomonas) maltophilia R.G. Munter, A.M. Yinnon, Y. Schlesinger, C. Hershko Abstract Stenotrophomonas maltophilia (formerly Xanthomonas maltophilia) is a gram-negative bacillus increasingly associated with serious nosocomial infec- tions. Here, the case of a 69-year-old female patient who developed prosthetic valve endocarditis associated with this organism is described. A review of the litera- ture revealed only 18 previous reports; eight involved native valves, the remainder prosthetic valves. Most cases were associated with risk factors, including intra- venous drug abuse (6 patients), infected intravenous lines (4 patients) or a recent invasive procedure (3 patients). The course of the disease appears to be indo- lent, but is otherwise similar to infective endocarditis associated with other gram-negative organisms. Anti- microbial therapy is complicated by multiple drug resistance of the organism; cotrimoxazole may be bene- ficial, if the isolate is susceptible, in combination with another agent. Five of nine (55%) patients who under- went valve replacement survived, as compared to three of seven (43%) who received antibiotic therapy only. Hence, surgery is not essential for survival in every case and depends as much on the individual patient's course as on established criteria for valve replacement in pros- thetic valve endocarditis. Introduction Stenotrophornonas rnaltophilia (previously named Xanthomonas rnaltophilia) is a gram-negative, nonfer- mentative bacillus that is ubiquitous in the environment [1]. It is increasingly recognized as a cause of serious infections in hospitalized patients [2-9]. These infec- tions are particularly common in patients who are immunocompromised due to underlying illness; as such, they have a significant morbidity and mortality. Infective endocarditis secondary to Stenotrophornonas maltophilia has been rarely described. We report a R.G. Munter, A.M. Yinnon (l~), Y. Schlesinger, C. Hershko Department of Medicine and InfectiousDisease Unit, Shaare Zedek Medical Center, P.O. Box 3235, Jerusalem 91031, Israel patient who developed prosthetic valve endocarditis and review 18 previously described cases from the liter- ature. Case Report A 69-year-old female patient was admitted to our hospital because of suspected infective endocarditis. Three months prior to admission the patient underwent aortic and mitral valve replacement because of severe rheumatic valvular disease. The postoperative course was complicated by a cerebrovascular accident and the ensuing need for prolonged mechanical ventilation. The patient developed nosocomial pneumonia; sputum cultures grew Pseudomonas aeruginosa and methicillin- resistant Staphylococcus aureus, and a 3 week course of ceftazidime and vancomycin was administered. Over the next 6 weeks the patient was successfully weaned from the respirator, and at the time of transfer to a rehabilitation hospital she had moderate residual hemi- paresis. Six weeks after transfer, the patient developed a fever of 38.5 ~ On examination, the patient looked fatigued, but did not appear to be in distress. There were no septic embolic phenomena. Cardiac examination revealed a 2/6 midsystolic ejection murmur radiating to the neck and a 1/4 diastolic murmur at the left sternal border. The leukocyte count was 13, 600 cram, the erythrocyte sedimentation rate (ESR) 80 mm/h. Blood cultures repeatedly grew Stenotrophomonas malto- philia. A transesophageal echocardiogram (TEE) revealed a 1.5xl cm mass attached to the anterior aspect of the prosthetic mitral valve. Prosthetic valve endocarditis was diagnosed. Antibiotic therapy consisted of ceftazidime and gentamicin, and subse- quently ciprofloxacin and cotrimoxazole. Treatment was changed in accordance with the varying antimicro- bial susceptibilities of the bacteria, as detected in blood cultures. Surgery with valve replacement was recom- mended, but the patient refused. During the subse- quent 40 days the patient's temperature fluctuated