Bloodstream infections caused by Stenotrophomonas maltophilia: a seven-year review

SummaryBackgroundStenotrophomonas maltophilia is a significant nosocomial pathogen, responsible for an increasing number of infections, particularly in immunocompromised patients.AimThis study describes the clinical and microbiological characteristics of patients with Stenotrophomonas maltophilia bacteraemia.MethodsWe reviewed the charts of 102 patients with Stenotrophomonas maltophilia bacteraemia over a seven-year period from 2001 to 2007 in two tertiary care centres in New York, USA.FindingsThere were 79 episodes (77.5%) related to nosocomial acquisition, 21 (20.6%) were healthcare-associated and two episodes (2%) were community-acquired. The most common source of bacteraemia was an infected central catheter in 44 patients (43.1%); 17 (16.6%) were related to neutropenic sepsis; nine (8.8%) were from an abdominal source; six (5.9%) were from a respiratory source, and the source of the bacteraemia was unclear in 26 cases (25.5%). The majority (94.1%) of the patients had central venous access devices. Intensive care unit stay, intubation, septic shock, neutropenia at the time of bacteraemia or carbapenem antibiotic use within 30 days of the episode were associated with mortality according to univariate analysis. By multivariate analysis, hypotensive shock and carbapenem use within 30 days of the episode were factors significantly correlated with mortality. The 102 isolates were mostly susceptible in vitro to trimethoprim–sulfamethoxazole (97.1%), levofloxacin (92.9%), ceftazidime (53.0%) and ticarcillin–clavulanic acid (49.2%).ConclusionOur data describe the characteristics of patients with Stenotrophomonas maltophilia bacteraemia and emphasize the importance of careful evaluation of vascular access devices in those patients.