title: Stenotrophomonas maltophilia bloodstream infection in patients with hematologic malignancies: a retrospective study and in vitro activities of antimicrobial combinations.
abstract: BACKGROUND
  Stenotrophomonas maltophilia causes serious infections in immunocompromised hosts. Here, we analyzed the clinical characteristics of S. maltophilia bloodstream infection (BSI) in patients with hematologic malignancies and evaluated in vitro synergistic effects of antimicrobial combinations.
  
  
  METHODS
  We retrospectively reviewed all consecutive episodes of S. maltophilia BSIs in adult hematologic patients from June 2009 to May 2014, with in vitro susceptibility and synergy tests using high-throughput bioluminescence assay performed for available clinical isolates.
  
  
  RESULTS
  Among 11,004 admissions during 5-year period, 31 cases were identified as S. maltophilia BSIs. The incidence rate of S. maltophilia BSI was 0.134 cases/1,000 patient-days. Overall and attributable mortality of S. maltophilia BSI was 64.5% and 38.7%, respectively. Severe neutropenia (adjusted hazard ratio [HR] 5.24, p =0.013), shock at the onset of BSI (adjusted HR 6.05, p <0.001), and pneumonia (adjusted HR 3.15, p =0.017) were independent risk factors for mortality. In vitro susceptibilities to ceftazidime, levofloxacin, ticarcillin-clavulanic acid (TIM) and trimethoprim-sulfamethoxazole (SXT) were 11.1%, 44.0%, 40.7%, and 88.9%, respectively. MIC50/MIC90 for moxifloxacin and tigecycline were 1/4 mg/L and 4/8 mg/L. The 50% and 90% fractional inhibitory concentrations (FIC(50)/FIC(90)) of clinical isolates against a combination of SXT and TIM were 0.500/0.750. For SXT plus levofloxacin or moxifloxacin, FIC(50)/FIC(90) were 0.625/1.000 and 0.625/0.625, respectively.
  
  
  CONCLUSIONS
  S. maltophilia BSIs show high mortality, which is related to severe neutropenia, shock, and S. maltophilia pneumonia. Based upon drug susceptibility testing, the primary treatment of choice for S. maltophilia BSIs should be SXT in hematologic patients, rather than quinolones, with combination therapies including SXT serving as a feasible treatment option.
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. yeon3120@naver.com.|Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. yeon3120@naver.com.
authors.forename: Sung-Yeon
authors.initials: SY
authors.lastname: Cho
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. symonlee@catholic.ac.kr.|Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. symonlee@catholic.ac.kr.|The Catholic Blood and Marrow Transplantation Center, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. symonlee@catholic.ac.kr.
authors.forename: Dong-Gun
authors.initials: DG
authors.lastname: Lee
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. sumichoi@catholic.ac.kr.|Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. sumichoi@catholic.ac.kr.
authors.forename: Su-Mi
authors.initials: SM
authors.lastname: Choi
authors.affiliation: Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. micropak@catholic.ac.kr.
authors.forename: Chulmin
authors.initials: C
authors.lastname: Park
authors.affiliation: Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. onlyjhs75@naver.com.
authors.forename: Hye-Sun
authors.initials: HS
authors.lastname: Chun
authors.affiliation: Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. yjpk@catholic.ac.kr.
authors.forename: Yeon-Joon
authors.initials: YJ
authors.lastname: Park
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. mdcjk@catholic.ac.kr.|Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. mdcjk@catholic.ac.kr.
authors.forename: Jae-Ki
authors.initials: JK
authors.lastname: Choi
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. happyjinns@catholic.ac.kr.|Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. happyjinns@catholic.ac.kr.
authors.forename: Hyo-Jin
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. zenithbr@catholic.ac.kr.|Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. zenithbr@catholic.ac.kr.
authors.forename: Sun Hee
authors.initials: SH
authors.lastname: Park
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. cmcjh@catholic.ac.kr.|Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. cmcjh@catholic.ac.kr.
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. jhyoo@catholic.ac.kr.|Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, 222, Banpo-daero, Seocho-gu, Seoul, Republic of Korea. jhyoo@catholic.ac.kr.
authors.forename: Jin-Hong
authors.initials: JH
authors.lastname: Yoo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D016470:Bacteremia / Q000188:drug therapy* / Q000276:immunology / Q000401:mortality; D004338:Drug Combinations; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy* / Q000276:immunology / Q000401:mortality; D019337:Hematologic Neoplasms / Q000150:complications / Q000276:immunology*; D006801:Humans; D016867:Immunocompromised Host; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012189:Retrospective Studies; D020615:Stenotrophomonas maltophilia / Q000302:isolation & purification; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D004338:Drug Combinations