Molecular characterization and antimicrobial susceptibility of 
extended-spectrum b-lactamases (ESBL) producing enterobactericiaceae (ESBLPE) causing urinary tract infections (UTI): Results from the Study for Monitoring Antimicrobial Resistance Trends (SMART), 2010–2015, South Africa

BACKGROUND: To better inform infection control and antibiotic stewardship programs, we investigated antimicrobial susceptibility trends and assessed the molecular characteristics of ESBLPE, particularly of Escherichia coli (EC) and Klebsiella pneumoniae (KP) isolates, from patients with UTI treated at 6 local healthcare centers. METHODS: Consecutive isolates from 147 patients were send to a central laboratory for species identification and drug susceptibility tests (Fig). Cochran-Armitage test was used to examine trends in susceptibility. EUCAST version 7.1 Minimum inhibitory concentration (MIC) interpretive criteria were used to identify susceptible isolates. RESULTS: All isolates were ESBL-producers based on phenotypic tests. EC and KP were the most frequent organisms identified comprising 138/147 (94%): there was no significant association between organism and LOS (Fig). We did not find any bla(KPC) genes; however, bla(CTX-M-15) genes, which were encountered in CAI as frequently as they were in HAI, was present in 5/6 (83%) EC and KP isolates not susceptible to carbapenems. 9/10 (90%) isolates not susceptible to carbapenems were also not susceptible to quinolones. CONCLUSION: Quinolones should be abandoned as empiric therapy for UTI with ESBLPE. TZP is not an ideal substitute that can protect carbapenems in South Africa. DISCLOSURES: All authors: No reported disclosures.