1461. Antimicrobial Susceptibility Patterns of Common Complicated Urinary Tract Infection Pathogens in US Hospitals, 2013–2018

BACKGROUND: In response to increasing rates of antimicrobial resistance, carbapenems have become first-line treatments for many infections. This, in turn, fosters the potential for resistance (CR). Efforts to mitigate the emergence of CR through carbapenem-sparing strategies must rest on a fundamental understanding of antibiotic resistance patterns among commonly encountered pathogens. Therefore, we examined the microbiology of complicated urinary tract infections (cUTI) in hospitalized patients in the United States. METHODS: We performed a multicenter retrospective cohort study in the Premier database of approximately 180 hospitals, 2013–2018. Using an ICD-9/10-based algorithm we identified all adult patients hospitalized with cUTI and included those with a positive blood or urine culture. Patients with carbapenem-resistant organisms were excluded. We examined the microbiology and susceptibilities to common cUTI antimicrobials (third-generation cephalosporin [C3], fluoroquinolones [FQ], trimethoprim-sulfamethoxazole [TMP/SMZ], fosfomycin [FFM], nitrofurantoin [NFT], and triple-resistant [TR]) over time. RESULTS: Among 28,057 organisms from 23,331 patients, the 3 most common pathogens were E. coli (EC, 41.0%), K. pneumoniae (KP, 12.1%), and P. aeruginosa (PA, 11.0%). Among these organisms, resistance to C3 was 10.4% among PA, 12.6% KP and 48.9% EC. EC was most likely to exhibit resistance to all agents of interest, and demonstrated the highest resistance rate to TMP/SMZ (61.5%), and lowest to NFT (10.4%). In contrast, KP had the highest rate of resistance to NFT (27.9%) and lowest to FQ (4.9%). The lowest rate of resistance among PA was to TMP/SMZ (1.9%), and highest to C3 (10.4%). The prevalence of TR in 2013–2014 and 2017–2018, respectively, was 34.2% and 37.4% for EC, 11.8% and 14.2% for KP, and 7.0% and 4.6% for PA. CONCLUSION: Among the most common pathogens isolated in hospitalized patients with cUTI, and particularly in EC, high and increasing single resistance and TR rates to common antimicrobials were evident, Current empiric treatment strategies may be insufficient against the growing threat of TR. DISCLOSURES: All authors: No reported disclosures.