Stenotrophomonas Maltophilia and Time to Appropriate Antibiotic Therapy

Abstract

Specific Aims: Determine time to appropriate therapy for S. maltophilia infection before implementation of mass spec. A second part of this project will evaluate the time to appropriate therapy after implementation of mass spec. The hypothesis is the time to appropriate therapy will decrease by > 2 days after implementation of mass spec. appropriate antibiotic therapy will be based on susceptibility data reported for each isolate of S. maltophilia. Potential appropriate therapy that will be evaluated includes high-dose sulfamethoxazole-trimethoprim (10-20 mg/kg/day based on TMP adjusted for renal function), ticarcillin- clavulanate plus aztreonam, moxifloxacin or levofloxacin, and ceftazidime. Methods: A retrospective chart review was done to evaluate time to identification and time to appropriate therapy for S. maltophilia as baseline data before implementation of mass spectrometry for earlier species identification. Subject selection included all patients between June 1, 2011 through May 31, 2012 with S. Maltophilia isolated from any source while admitted to the University of Arizona Medical Center-University Campus, Tucson, AZ. Patients with initial S. maltophilia isolated from a post-mortem sample or were colonizers were excluded. Main Results: There were 86 subjects included in the study based on inclusion and exclusion criteria. There were 60 subjects that received appropriate therapy for S. maltophilia coverage. The averaged time to initiation of appropriate antibiotic prior to the implementation of mass spectrometer was determined to be 6.5 days. Conclusion: Since S. maltophilia is not susceptible to many antibiotics used as empiric therapy, early identification of the pathogen via mass spectrometry, in addition to pharmacist intervention, may lead to initiation of appropriate antibiotics that is earlier than an average of 6.5 days found in this study.