Objectives Multiple studies have identified cross-sectional relationships between antibiotic use and bacterial resistance. The aim of this study was to analyse the susceptibility of multidrug-resistant (MDR) and non-MDR (nMDR) isolates of Escherichia coli and Klebsiella spp to cephalosporins: ceftazidime (CTZ), ceftriaxone (CTX), cefepime (CEF) and fluoroquinolones: ciprofloxacin (CIP) and levofloxacin (LEV) in a tertiary healthcare centre from 2014 to 2018. In addition, we aimed to evaluate a correlation between the antibiotic utility and susceptibility of the selected enterobacteria.

Methods Antibiotics consumption and antimicrobial resistance were monitored in a tertiary care university hospital from 2014 to 2018. Utilisation of antibiotics in the observed period was expressed as defined daily dose (DDD) per 100 bed/days (DBD). Bacterial susceptibility was reported as the percentage of susceptible results among all tested isolates from all patient samples. In further analysis, bacterial strains were considered as MDR or nMDR species. An MDR bacterial strain was defined as one with acquired non-susceptibility to at least one agent in three or more antimicrobial categories.

Results Our results suggest that cephalosporins were the most used antibiotics, followed by fluoroquinolones, during the entire observed period 2014–2018. Our findings show that MDR isolates of E. coli had an increasing trend in susceptibility in relation to CTX (p=0.005), whereas a decreasing trend was observed for MDR isolates of E. coli susceptibility towards CIP and LEV (p<0.001). Klebsiella spp susceptibility for MDR isolates showed a decreasing trend in relation to CEF (p<0.001) and both fluoroquinolones (p<0.001). A significant negative association between CEF consumption and Klebsiella spp MDR isolates susceptibility was observed (p=0.045).

Conclusion Implementation of antimicrobial stewardship programmes with early detection and close monitoring of MDR bacterial strains of E. coli and Klebsiella spp may be a crucial step in reducing the menace of antimicrobial resistance, which is now a global problem.