A 4-Year Antimicrobial Stewardship Program Successfully Reduces Antibiotic Resistance

Antimicrobial resistance (AMR) poses a significant and growing threat to public health. The main driver of these pathogens becoming increasingly difficult to treat is an over-prescription of antibiotics.

Antimicrobial stewardship programs aim to make antibiotic prescriptions more intentional. One study, presented at the IDWeek 2022 conference, analyzed whether a successfully implemented antimicrobial stewardship program (ASP) could reduce antimicrobial resistance.

The investigators monitored pharmacy data from 2015 (pre-ASP intervention), and from 2016-2019 (post-intervention). They examined the antibiotic consumption and resistance rates of a 427-bed tertiary general hospital. Utilizing the clinical microbiology laboratory’s electronic database, the investigators obtained AMR data.

To achieve a successful ASP, the investigators employed a pre-authorization intervention strategy for protected antibiotics, including tigecycline, carbapenems, quinolones, glycopeptides, daptomycin, colistin, and linezolid. They deescalated or switched from intravenous to oral administration, appropriately selecting the duration of chemoprophylaxis in surgery.

After 4 years of the ASP, the investigators noted significant reductions in total antibiotics, total antibiotics, colistin, carbapenems, quinolones, and tigecycline consumption. They recorded far lower resistance rates in 2019 than in 2015 for Pseudomonas aeruginosa and Klebsiella pneumoniae.

There were no significant changes in the resistant rates of Acinetobacter baumannii isolates, which remained highly resistant to more than 90% of carbapenems in the hospital. However, infections caused by Gram-positive pathogens were reduced.

Lower rates of vancomycin-resistant enterococci were noted after the implementation of the ASP; for E faecium, rates reduced from 50.0% in 2015 to 30.4% in 2019, and from 6% to 0.6% for E faecalis. Methicillin-resistant S aureus isolates had increased antimicrobial resistance, 40% in 2019 versus 31.1% in 2015, which the investigators hypothesized could be because most of these pathogens are not hospital-acquired.

The study authors concluded that the antimicrobial stewardship program successfully reduced antibiotic consumption at their hospital, and reduced antimicrobial resistance in dangerous pathogens.

This study, “Impact of A Four-Year Antimicrobial Stewardship Program on Antimicrobial Resistance,” was presented by Georgios Chrysos at IDWeek 2022, held October 19-23, 2022, in Washington, D.C.