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 bacteremia

Table 1.
FactorMortalityHR95%CIP-value
With
factor 
Without
factor 
T>39.0¡æ 75% 16.7% 2.490 1.318-4.704 0.005 
Septic shock 90.0% 25.0% 2.544 1.473-4.393 0.001 
Respiratory failure 100% 20.8% 4.672 2.366-9.225 0.000 
Treatment outcome for hematological diseases 
Remission 10.0% 85.7% 0.247 0.116-0.526 0.000 
FactorMortalityHR95%CIP-value
With
factor 
Without
factor 
T>39.0¡æ 75% 16.7% 2.490 1.318-4.704 0.005 
Septic shock 90.0% 25.0% 2.544 1.473-4.393 0.001 
Respiratory failure 100% 20.8% 4.672 2.366-9.225 0.000 
Treatment outcome for hematological diseases 
Remission 10.0% 85.7% 0.247 0.116-0.526 0.000 

HR, hazard ratio; CI, confidence interval; HSCT, Hematopoietic stem cell transplantation

Table 2.

Multivariate analysis of prognostic factors associated with mortality from S. maltophilia bacteremia

FactorHR95%CIP-value
Respiratory failure 2.688 1.297-5.569 0.008 
Remission after treatment for hematological diseases 0.367 0.153-0.879 0.025 
FactorHR95%CIP-value
Respiratory failure 2.688 1.297-5.569 0.008 
Remission after treatment for hematological diseases 0.367 0.153-0.879 0.025 

HR, hazard ratio; CI, confidence interval

Table 3.

Susceptibility pattern of the 34 patients with Stenotrophomonas maltophilia bacteremia

Antimicrobial agentsS (%)I (%)
Ceftazidime 24(70.6%) 1(2.9%) 
Cefoperazone 19(44.1%) 6(17.6%) 
Sulbactam and Cefoperazone 20(58.8%) 5(14.7%) 
Piperacillin 7(20.6%) 6(17.6%) 
Piperacillin-Tazobactam 11(32.3%) 7(20.6%) 
Amikacin 6(17.6%) 0(0%) 
Ciprofloxacin 28(82.4%) 1(2.9%) 
Antimicrobial agentsS (%)I (%)
Ceftazidime 24(70.6%) 1(2.9%) 
Cefoperazone 19(44.1%) 6(17.6%) 
Sulbactam and Cefoperazone 20(58.8%) 5(14.7%) 
Piperacillin 7(20.6%) 6(17.6%) 
Piperacillin-Tazobactam 11(32.3%) 7(20.6%) 
Amikacin 6(17.6%) 0(0%) 
Ciprofloxacin 28(82.4%) 1(2.9%) 

S, susceptible; I, intermediately susceptible.

Disclosures

No relevant conflicts of interest to declare.

Author notes

*

Asterisk with author names denotes non-ASH members.

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