The Regional Antibiogram Is an Important Public Health Tool to Improve Empiric Antibiotic Selection, Stenotrophomonas maltophilia As A Case Example

Background Early appropriate antibiotic selection is life saving in sepsis. Facility-level antibiograms inform antibiotic selection after pathogen identification and before susceptibility results are available, but only if ≥ 30 isolates from a given species are tested in the prior year. Stenotrophomonas maltophilia (SM) has a complex resistance profile and is associated with an 8-fold mortality increase. We hypothesized that a regional antibiogram may help inform clinical decision-making for severe SM infections. Methods To generate a regional SM antibiogram, we conducted a cross-sectional, voluntary survey of 2015 cumulative facility-level antibiograms from all hospitals in LA county. Non-respondents were contacted to improve response rates. Isolates from sterile sources were pooled. Susceptibility was aggregated and percent susceptible was calculated only when all isolates were tested, i.e. not reflex testing. To identify optimal combination empiric therapy for SM infections, we generated a combination antibiogram using broth microdilution results from a single tertiary care facility in LA. Results Antibiograms were submitted by 85/100 (85%); 50 hospitals (59%) reported SM (n = 1719 isolates, Table 1). Hospitals commonly (25/50) reported data for