Objective. To evaluate trends and association between antibiotic consumption and resistance during an eight-year period, from 2006 to 2013. Design. Prospective multicenter study. Setting and participants. Intensive Care Units (ICUs) participating in the four editions of the Italian nosocomial infections surveillance in the ICU Network (Sorveglianza Prospettica delle Infezioni Nosocomiali nelle Unità di Terapia Intensiva, SPIN-UTI project). Main outcome measures. The isolation density of selected species of microorganisms, antibiotic resistance rates (RRs), incidence density of resistant isolates and antimicrobial usage density were calculated. Results. RRs of carbapenem-resistant Acinetobacter baumannii, of carbapenem-resistant Klebsiella pneumoniae, of third-generation cephalosporin (3GC)-resistant K. pneumoniae and of 3GC-resistant Escherichia coli showed significant increasing trends (p ≤0.001). The consumption of each antibiotic class varied with years, although not significantly. Significant strongly positive correlations were detected between RRs and antibiotic consumption. Conclusions. The present study describes high RRs and increasing trends of resistant microorganisms and highlights the need for continuous comprehensive strategies targeting not only the prudent use of antibiotics, but also infection control measures to limit the epidemic spread of resistant isolates.
