942. Comparison of Antibiotic Susceptibility Across Minnesota Hospitals in 2019 and 2020 Using a New Statewide Antibiogram

Abstract

Abstract Background Surveillance is imperative to successful antibiotic stewardship, but active surveillance is resource-intensive. Regional antibiograms provide a supplementary method of surveillance while conserving resources. We developed the first statewide antibiograms to track susceptibility across the state of Minnesota and compared 2019 and 2020 data. Methods Hospital antibiograms for 2019 and 2020 were submitted to the Minnesota Department of Health in January 2022. Twelve organisms (Enterococcus faecalis, Enterococcus faecium, methicillin-resistant Staphylococcus aureus, methicillin-susceptible S. aureus, S. aureus, Acinetobacter spp., Enterobacter spp., Escherichia coli, Klebsiella aerogenes, K. oxytoca, K. pneumoniae, and Pseudomonas aeruginosa) were selected for analysis against 32 drugs, leading to a total of 142 unique organism/agent combinations. The number of isolates and percent susceptibility from each antibiogram were used to calculate a weighted average percent susceptibility as the state-level susceptibility. Chi-square analysis compared the proportion of susceptible to non-susceptible isolates between the years. Results Submitted antibiograms (n=40) represented 30% of Minnesota hospitals. The total number of isolates reported decreased by 5% from 2019 (n=85,010) to 2020 (n=80,781), with E. coli having the greatest proportion (2019=41.7%, 2020=39.5%) of the total isolates. Significant changes in susceptibility proportions occurred in 33% of analyzed organism/agent combinations, with 68% of these showing increased susceptibility in 2020 compared to 2019. All antibiotics tested against P. aeruginosa demonstrated a statistical increase in susceptibility from 2019 to 2020 (Figure 1). Figure 1 Statewide susceptibility profile of P. aeruginosa in Minnesota, 2019 and 2020. Antimicrobial agents grouped by class from narrow spectrum to broad spectrum, cephalosporins ordered by generation. *denotes statistical significance (p<0.05). Conclusion Analysis of statewide antibiograms for 2019 and 2020 demonstrated overall stability in antimicrobial susceptibility, with two-thirds of organism/agent combinations showing no significant changes. In those with significant changes, the majority exhibited an increase in susceptibility. Susceptibility changed more frequently in gram-negative organisms than gram-positive organisms. Ongoing collection of antibiograms will be used to assess regional and statewide susceptibility trends across Minnesota. Disclosures Elizabeth B. Hirsch, PharmD, FCCP, FIDSA, Melinta: Advisor/Consultant|MeMed: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support.