Aim: To decrease the incidence and resistance rates of extended-spectrum β-lactamases (ESBL) Klebsiella pneumoniae (KP) by restriction of the use of third-generation cephalosporins (3GCs) and fluoroquinolones. Methods: Consumption of 3GCs, fluoroquinolones, and carbapenems in association with ertapenem and fluoroquinolone-resistant KP isolates, were analyzed in 21 months by autoregressive integrated moving average models. A follow-up analysis was performed 5 years later. Results: Consumption of 3GCs decreased significantly during the postintervention period. Their restriction was associated with a decrease in ertapenem-resistant KP isolates by 17.5%. Fluoroquinolone, 3GCs, and carbapenem use did not significantly predict the percentage of ertapenem-resistant KP isolates. Fluoroquinolone, but not cephalosporin use, significantly predicted the percentage of fluoroquinolone-resistant isolates, with an increase of 1 defined daily dose (DDD) of fluoroquinolone/100 occupied bed-days (OBDs) corresponding to a 0.32% increase of fluoroquinolone-resistant isolates (p = 0.008). A decrease of 1 DDD of carbapenem/100 OBD was associated with a 16.94% increase of fluoroquinolone-resistant isolates (p = 0.007). Five years later, the consumption of all three antimicrobial classes increased significantly compared with the 2011-2013 period, whereas ertapenem-resistant KP rates significantly decreased. Conclusion: This study may bring a valuable contribution to the understanding of the intricate association between antibiotic consumption and bacterial resistance. Reporting a spectrum of different results could present a useful basis for more profound research of various interventions' effects.
