Introduction:
Antibiotic resistance is a critical public health issue, both clinically and economically. Klebsiella pneumoniae (K. pneumoniae) is a common cause of healthcare-associated infections and has worrying levels of antibiotic resistance. The antibiotic resistance of K. pneumoniae was investigated in the L’Aquila Hospital using the Drug Resistance Index (DRI), a measure of antibiotic effectiveness whose validity was subject of discussion.

Materials and methods:
DRI was calculated by multiplying proportion of consumption of selected antibiotic class and proportion of all K. pneumoniae resistant to that antibiotic class. The DRI in the L’Aquila Hospital for the years 2019 and 2020 have been calculated and then compared to national DRI. Local resistance and antibiotic consumption data were obtained by analysis laboratory of the L’Aquila Hospital, and by the Management Control Office. National data were obtained by the national surveillance system on antibiotic resistance, and by the Italian Medicines Agency.

Results:
The local prevalence of resistance to β-lactamases was higher than those to carbapenems in both years: 35.6% vs 15.7% in 2019; 32.0% vs 17.6% in 2020. Prevalence of resistance to β-lactamases showed a reduction from 35.6% to 32.0%; instead, prevalence of resistance to carbapenems increased from 15.7% to 17.6%. L’Aquila Hospital DRI was 29.9% in 2019 and 28.9% in 2020. In Italy, the prevalence of resistance against β-lactamases was higher than those to carbapenems in both years: 60.0% vs 34.7% in 2019 and 57% vs 33.0% in 2020. National DRI was 57.7% in 2019 and 54.3% in 2020. In 2019 and in 2020 the most consumed antibiotics were β-lactamases, the less were carbapenems.

Conclusions:
DRI calculated in LAquila Hospital was significantly lower than the national, but both showed a downward trend, indicating an improvement in the management of antibiotics.