The Role of Stenotrophomonas Maltophilia in Refractory Chronic Rhinosinusitis

Background Stenotrophomonas maltophilia is a multidrug-resistant Gram-negative bacillus that has been implicated in serious nosocomial infections. This microbe has also been isolated from sinus cultures in refractory chronic rhinosinusitis (CRS). The goal of this study was to elucidate the implications of S. maltophilia–positive cultures in the setting of CRS. The objectives of the study were (1) to define clinical and microbiological characteristics and (2) to assess management strategy and overall outcomes of S. maltophilia–positive sinus cultures in CRS patients. Methods A retrospective review was performed of 101 patients over a 5-year period. Results The mean age was 56.9 years with a female/male ratio of 1.1:1. Previous sinus surgery had been performed in 90.1% of patients. Greater than 97% of patients had been given antibiotics in the previous 6 months. The most common presenting symptom was discolored nasal drainage (76.2%) with endoscopic evidence of pus or crusting in 83.2% of cases. Monotherapy with trimethoprim sulfamethoxazole (TMX) or fluoroquinolones was used in 41 and 26%, respectively. This intervention resulted in overall symptom and endoscopic improvement in 70% of cases. Conclusion The presence of S. maltophilia isolates on culture are associated with clinically relevant symptoms and endoscopic findings in patients with refractory CRS. Despite its multidrug-resistant nature, monotherapy with TMX or fluoroquinolones appears to be effective in providing patients with bacterial infection with symptom relief in a majority of cases.