Stenotrophomonas maltophilia ventilator-associated pneumonia. A retrospective matched case-control study

Johannes B. J. Scholte*, Tan Lai Zhou, Dennis C. J. J. Bergmans, Gernot G. U. Rohde, Bjorn Winkens, Helke A. Van Dessel, Tom P. J. Dormans, Catharina F. M. Linssen, Paul M. H. J. Roekaerts, Paul H. M. Savelkoul, Walther N. K. A. van Mook

*Corresponding author for this work

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Background: Stenotrophomonas maltophilia is increasingly identified in critically ill patients, but it is considered a pathogen with limited pathogenicity and it is therefore infrequently targeted. This study explores whether S. maltophilia may cause ventilator-associated pneumonia (VAP) and whether it affects intensive care unit (ICU) mortality and 28-day mortality when compared to VAP caused by other Gram-negative bacilli.Methods: Retrospective analysis of a 19-year prospectively collected database. Stenotrophomonas maltophilia as a cause was considered in VAP-suspected cases when S. maltophilia growth of 10(4) cfu/ml was detected in bronchoalveolar lavage fluid analysis. Cases were matched on hospital, gender, age and acute physiology and chronic health evaluation II score in a 1:3 ratio with controls from the same database suffering from VAP caused by other Gram-negative bacilli.Results: Eight cases met the inclusion criteria, of which three were labelled as probable' SM-VAP and three as possible' SM-VAP. These six patients constitute 1.8% of all VAPs in the studied period. No significant differences in baseline characteristics and duration of mechanical ventilation (p=0.68), length of stay in the ICU (p=0.55) and hospital (p=0.84) between cases and controls were identified between cases and controls. Intensive care unit mortality odds ratio was 1.7 (p=0.55; 95% CI 0.3-10.5) and 28-day mortality odds ratio was 1.4 (p=0.70; 95% CI 0.2-9.1).Conclusions:Stenotrophomonas maltophilia is a possible, yet infrequent cause of VAP. No outcome differences were found when compared to matched VAP caused by other Gram-negative bacilli.
Original languageEnglish
Pages (from-to)738-743
Number of pages6
JournalInfectious Diseases
Issue number10
Publication statusPublished - 2016


  • Intensive care unit
  • mechanical ventilation
  • mortality
  • multidrug-resistant
  • Stenotrophomonas maltophilia
  • ventilator-associated pneumonia

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