A Study in the Clinical Characteristics of Stenotrophomonas Maltophilia Bacteremia in Hematological Patients

Abstract

Introduction: Stenotrophomonas maltophilia is an important nosocomial pathogen, particularly in immunocompromised patients, especially in patients with hematologic diseases.Methods: We reviewed the clinical characteristics and prognosis of patients with S. maltophilia bacteremia over a five-year period from January 2010 to December 2014. Species identification was performed using the automated Vitek 2 compact system (bioMe rieux).Results: The incidence of S. maltophilia bacteremia was 25.1 per 10 000 admissions in our study. Thirty-four patients (median age: 34 years; 64.7% males) with S. maltophilia bacteremia were analyzed. The S. maltophilia bacteremia related 30-day mortality was 44.1%. Risk factors associated with mortality in patients with S. maltophilia infection in the univariate and multivariate analysis were represented in Tables I and II. In the univariate analysis, risk factors included T>39.0¡æ, septic shock, respiratory failure and non-remission after treatment for primary hematological diseases (P <0.05). In the multivariate analysis, respiratory failure and non-remission status after treatment forhematological diseases were independent prognostic factors for mortality. In vitro susceptibility was higher to ciprofloxacin(82.4%), ceftazidime(70.6%), sulbactam and cefoperazone(58.8%), which was shown in Table III.Conclusion: Combination regimens with ciprofloxacin and ceftazidime, or sulbactam and cefoperazone could be alternative treatment. Novel antibiotics are required for treatment of S. maltophilia infection, as well as infection control practices of environmental reserves, rapid detection of pathogens, risk stratification strategy and appropriate treatment for primary hematologic malignancies, which might conjointly contribute to better survival outcome of S. maltophilia bacteremia.Univariate analysis of prognostic factors associated with mortality from S. maltophilia bacteremiaTable 1FactorMortalityHR95%CIP-valueWithfactorWithoutfactorT>39.0¡æ75%16.7%2.4901.318-4.7040.005Septic shock90.0%25.0%2.5441.473-4.3930.001Respiratory failure100%20.8%4.6722.366-9.2250.000Treatment outcome for hematological diseasesRemission10.0%85.7%0.2470.116-0.5260.000HR, hazard ratio; CI, confidence interval; HSCT, Hematopoietic stem cell transplantationTable 2Multivariate analysis of prognostic factors associated with mortality from S. maltophilia bacteremiaFactorHR95%CIP-valueRespiratory failure2.6881.297-5.5690.008Remission after treatment for hematological diseases0.3670.153-0.8790.025HR, hazard ratio; CI, confidence intervalTable 3Susceptibility pattern of the 34 patients with Stenotrophomonas maltophilia bacteremiaAntimicrobial agentsS (%)I (%)Ceftazidime24(70.6%)1(2.9%)Cefoperazone19(44.1%)6(17.6%)Sulbactam and Cefoperazone20(58.8%)5(14.7%)Piperacillin7(20.6%)6(17.6%)Piperacillin-Tazobactam11(32.3%)7(20.6%)Amikacin6(17.6%)0(0%)Ciprofloxacin28(82.4%)1(2.9%)S, susceptible; I, intermediately susceptible. DisclosuresNo relevant conflicts of interest to declare.