1456. Increase in Resistance to Antibiotics in Enterobacteriaceae from Ambulatory Urinary Samples in Buenos Aires City

BACKGROUND: During the last years, an increase in the rates of resistance among causal agents of urinary tract infection (UTI) has been reported, even in community-acquired infections. This increase in resistance is problematic since it affects most therapeutic agents used in the ambulatory setting and often implies the lack of oral options for treatment. The aim of this study was to determine whether there were changes in the prevalence of resistance among samples from patients with UTI in the ambulatory setting caused by the most common Enterobacteriaceae. METHODS: We analyzed the resistance profiles of the three most common Enterobacteriaceae recovered in cultures from urinary samples of ambulatory adult patients, processed in a reference Laboratory in Buenos Aires City; according to calendar year, from January 1, 2010 till December 31, 2017. Sensitivity to antibiotics was determined using disk-diffusion methods and interpreted according to CLSI guidelines. RESULTS: A total of 26774 urinary samples were processed in the mentioned period and were analyzed for this study. Of these, 84% were from women, mean (SD) age was 59.7(20.4) years. Distribution according to bacterial genus and species was: E. coli: 84.6%; Klebsiella pneumoniae: 9.9%; Proteus sp.: 5.5% There were no significant differences in gender, mean age or bacterial genus/species distribution according to calendar year. When comparing 2010 to 2017 we found significant differences in the prevalence of resistance to fluoroquinolones: 26.6% vs. 33.6% respectively, P < 0.01; third G cephalosporins: 5.2% vs. 10.0%, P < 0.01; carbapenems: 0.2% vs. 0.4%, P < 0.01. Prevalence of resistance to TMS (39.0% vs. 40.2%) and nitrofurans (11.9% vs. 10.3%) remained stable. Results of analysis of resistance according to bacterial genus/species comparing results from 2010 to results from 2017 are shown on the table. CONCLUSION: Resistance to antibiotics in Enterobacteriaceae recovered from urinary samples has increased significantly in the last years, especially for quinolones, third G cephalosporins (100% increase) and carbapenems (100% increase). Resistance to TMS was high but remained stable. E coli shows very good sensitivity to nitrofurantoin. It is key to improve and amplify the measures to prevent emergence of resistance and aim to revert this increasing trend in urinary tract infections from the community. [Image: see text] DISCLOSURES: All authors: No reported disclosures.