Stenotrophomonas maltophilia: A Case Series and Review for an Uncommon Cause of Peritoneal-Dialysis-Associated Infection

Peritonitis is a common and potentially serious complication of peritoneal dialysis (PD). Common organisms include Staphylococcus Aureus, enterococci, and coagulase-negative staphylococcus. However, Stenotrophomonas maltophilia (S. maltophilia) is an uncommon cause of PD-related infection. We describe a series of three cases of S. maltophilia PD infection (two cases of PD peritonitis and one case of PD exit-site infection) that were identified over a seven-week period in a single centre. The cases were treated with antibiotics (the primary antibiotic being co-trimoxazole) for a mean duration of 30 ± 7.9 days. All of the patients required PD catheter removal due to treatment failure with antibiotics. Hospital admission was required in two of the cases and one case resulted in mortality, with the cause of death directly associated with complications from S. maltophilia infection. A multi-disciplinary team using root-cause analysis did not identify a common link between our cases but highlighted possible risk factors contributing to these presentations. Given the relative rarity of S. maltophilia, evidence on its management options remains limited. In this article, we draw upon our own experiences and examine the literature available from previously published case reports and series. These reports highlight S. maltophilia as a complex and challenging organism to treat. Our experience demonstrated the importance of early PD catheter removal in S. maltophilia PD infection, as this is likely more effective than prolonged antibiotic therapy and hence a safer management option, considering the resistant nature of S. maltophilia.