326. Stenotrophomonas maltophilia Resistance in Military Trauma Patients
Session: Poster Abstract Session: HAI: Multi Drug Resistant Gram Negatives
Thursday, October 27, 2016
Room: Poster Hall
  • Micro steno ID Week poster.pdf (487.1 kB)
  • Background: Stenotrophomonas maltophilia is as an emerging pathogen in critically ill trauma patients. This study identifies S. maltophiliadistribution, susceptibility, and risk factors for resistance in a military trauma population.

    Methods: All S. maltophilia isolates prospectively collected during the Trauma Infectious Disease Outcomes Study (TIDOS ) were included (9/09-9/14). Unique initial isolates were defined as differing in site, resistance and pulse-field gel electrophoresis (PFGE) patterns; serial isolates as ≥7 days between isolation. BD Phoenix™BD Emerge™(NMIC300) panels were used for susceptibility testing. Clonality was assessed with PFGE. Demographics, trauma-related characteristics, isolate source, presence of polymicrobial infection, and antimicrobial exposure before and after initial isolation were evaluated. Susceptibilities were defined by CLSI criteria [trimethoprim-sulfamethoxazole (TS), ticarcillin-clavulanate (TC), ceftazidime (CZ), levofloxacin (LV) minocycline (MC)] or MIC [moxifloxacin (MX), ciprofloxacin (CP), tigecycline (TG)].

    Results: Of 2,699 TIDOS patients, 66 patients with 67 unique initial isolates were included. Sources were wound (62%), respiratory (27%), blood (7%), urine (1%), and other (3%) with 72% resistant to ≥1 antimicrobial. There was no evidence of clonal spread by PFGE. There was a trend towards increased resistance in wound isolates and patients with injury severity scores (ISS) >25 (p=0.05). Higher initial CP MICs were associated with increasing time from injury to initial isolate (p=0.01). CZ resistance was associated with LV resistance, and higher MX, CP, and TG MICs (p<0.01). Of 9 patients identified with 26 unique serial isolates, all had an ISS >25 and resistance to ≥1 antimicrobial. Comparing all initial to serial isolates, susceptibilities decreased for TS (from 99% to 81%), CZ (42% to 4%), LV (82% to 31%), and TC (67% to 31%). All isolates remained susceptible to MC. Initial and serial isolate MICs for CP, MX, and TG were ≤2µg/mL in 28% and 8%, ≤4µg/mL in 97% and 89% and ≤2µg/mL in 86% and 23% respectively.

    Conclusion: S. maltophilia resistance in trauma patients may be seen with higher injury severity, increased time from injury to isolation, and in serial isolates.

    Shane Patterson, M.D.1, Katrin Mende, PhD2, Ping Li, MS3, Dan Z. Lu, MS3, Clinton K. Murray, MD, FIDSA4, David R. Tribble, MD, DrPH, FIDSA5 and Dana M. Blyth, M.D.6, (1)San Antonio Military Medical Center, San Antonio, TX, (2)Infectious Disease Clinical Research Program, Uniformed Services University, Bethesda, MD, (3)Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, (4)Infectious Disease Service, Brooke Army Medical Center, Fort Sam Houston, TX, (5)Infectious Disease Clinical Research Program (IDCRP), Uniformed Services University of the Health Sciences, Bethesda, MD, (6)San Antonio Military Medical Center, JBSA Fort Sam Houston, TX


    S. Patterson, None

    K. Mende, None

    P. Li, None

    D. Z. Lu, None

    C. K. Murray, None

    D. R. Tribble, None

    D. M. Blyth, None

    Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.