Impact of Antibiotic Consumption on Antimicrobial Resistance to Invasive Hospital Pathogens

The aim of our investigation is to correlate the wholesale data on antibiotic consumption expressed in daily doses per 1000 inhabitants per day (DID) with the resistance rate of invasive pathogen bacteria from 2017 to 2021. The data on antimicrobial resistance were collected from an analysis of the primary isolates of hospitalized patients. According to the CAESAR manual, the selected pathogens isolated from blood culture and cerebrospinal fluids were tested. The consumption of antibiotics for systematic use showed a statistically significant increasing trend (β = 0.982, p = 0.003) from 21.3 DID in 2017 to 34.5 DID in 2021. The ratio of the utilization of broad-spectrum to narrow-spectrum antibiotics increased by 16% (β = 0.530, p = 0.358). The most consumed antibiotic in 2021 was azithromycin (15% of total consumption), followed by levofloxacin (13%) and cefixime (12%). A statistically positive significant correlation was discovered between the percentage of resistant isolates of K. pneumoniae and consumption of meropenem (r = 0.950; p = 0.013), ertapenem (r = 0.929; p = 0.022), ceftriaxone (r = 0.924; p = 0.025) and levofloxacin (r = 0.983; p = 0.003). Additionally, the percentage of resistant isolates of E. coli and consumption of ertapenem showed significant correlation (r = 0.955; p = 0.011). Significant correlation with consumption of the antibiotics widely used at the community level, such as levofloxacin, and resistance isolated in hospitals indicates that hospital stewardship is unlikely to be effective without a reduction in antibiotic misuse at the community level.