BackgroundAntibiotic-resistant healthcare-associated infections (HAI) threaten patient safety and public health. HAI reported by California hospitals to the National Healthcare Safety Network include pathogen and antibiotic susceptibility information. We analyzed HAI data to measure regional changes in antibiotic resistance (AR) over time among select bacteria.MethodsWe analyzed central line-associated bloodstream infection (CLABSI) data using log binomial regression models to estimate annual change in the proportion of pathogens resistant to carbapenems, extended-spectrum cephalosporins, methicillin/oxacillin, and multidrug (MDR) combinations for the reporting years 2011–2017. We aggregated HAI CLABSI, catheter-associated urinary tract infection (CAUTI), and surgical site infection (SSI) data in 2-year increments (i.e., 2014–2015, 2016–2017) to assess changes in percent resistance by county when data for 30 or more pathogens were available.ResultsAmong CLABSI reported from 2011 to 2017, there were no significant changes in the proportion of carbapenem-resistant Enterobacteriaceae (CRE) (Figure 1; risk ratio [RR]: 0.97, 95% CI: 0.92, 1.03; P = 0.32), methicillin/oxacillin-resistant S. aureus (MRSA) isolates (RR: 0.98, 95% CI: 0.96, 1.00; P = 0.06) or Pseudomonas aeruginosa with an MDR phenotype (RR: 1.02, 95% CI: 0.95, 1.10; P = 0.54). The proportion of E. coli with MDR and extended-spectrum β-lactamase (ESBL) phenotypes increased by 7% (RR: 1.07, 95% CI: 1.02, 1.12; P < 0.01) and 4% (RR: 1.04, 95% CI: 1.01, 1.08; P = 0.02) per year, respectively. Percentages of AR among aggregated CAUTI, CLABSI and SSI pathogens varied by county and time period (Figures 2 and 3).Figure 1.Figure 2.Figure 3.ConclusionIncreases in antibiotic resistant phenotypes among E. coli, and unchanged prevalence of MDR Pseudomonas aeruginosa, CRE, and MRSA among reported HAI underscore the need for continued infection prevention and antibiotic stewardship efforts in California. Local public health departments can use these analyses to target coordinated AR prevention initiatives with healthcare facilities in their regions.Disclosures All authors: No reported disclosures.