Insights for the Growth of Stenotrophomonas maltophilia in a Diabetic Patient with Long-Term Antibiotic Use: A Case Study.

Background: Stenotrophomonas maltophilia is an uncommon gram-negative bacterium often found in individuals with long-standing broad-spectrum antibiotic use or catheter use; individuals undergoing hemodialysis; and individuals with prolonged respiratory disease, specifically, cystic fibrosis. To our knowledge, there are few reported cases of S maltophilia being the causative pathogen of infection in a diabetic foot wound.

Methods: Following multiple surgical procedures and deep tissue cultures, S maltophilia was determined to be a secondary opportunistic colonizer of the wound, necessitating a change in antibiotic therapy.

Results: The cultured pathogen was sensitive to ceftazidime, levofloxacin, and trimethoprim-sulfamethoxazole. The treatment team chose to use ceftazidime, as it also provided antibiotic coverage for the initial wound and blood cultures. Change in antibiotic therapy was initiated following multiple surgical procedures and angioplasty of the lower limb. The patient was discharged with a peripheral intravenous central catheter for outpatient antibiotic therapy.

Conclusions: Prolonged exposure to broad-spectrum antibiotics in individuals with multiple comorbidities including diabetes mellitus provides an advantageous environment for growth of uncommon multidrug-resistant organisms. Stenotrophomonas maltophilia may complicate the treatment of diabetic foot infections as an opportunistic pathogen. Understanding the implication of long-term broad-spectrum antibiotic treatment in the diabetic patient is important in managing postoperative complications and determining the correct course of treatment. The emergence of atypical pathogens in diabetic wounds must be managed appropriately.