A multicenter study on antimicrobial resistance in bloodstream pathogens isolated in Korea: a survey study

Background: Bacterial antimicrobial resistance (AMR) is a major contributor to the mortality and disease burden associated with bloodstream infections worldwide. The authors investigated the AMR rates of bacterial isolates obtained from blood cultures in 2023 to provide essential baseline data for AMR management and compared these findings with Korea Global Antimicrobial Resistance Surveillance System (Kor-GLASS) (2023) data limited to the first isolate group in our data. Methods: Through a multicenter survey, we collected AMR data for bacteria causing bloodstream infections in 2023. Sixteen university-affiliated hospitals participated in the survey; nine provided the first isolate data, and seven reported duplicate isolate data. The survey targeted five gram-positive organisms (Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Enterococcus faecalis, Enterococcus faecium) and four gram-negative organisms (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa). Results: Resistance to oxacillin was significantly higher for S. epidermidis (76.9%−83.2%) than S. aureus (39.1%−47.4%), while S. pneumoniae showed 38.9%−51.7% resistance to penicillin. Vancomycin resistance was significantly higher in E. faecium (33.6%−37.8%) than E. faecalis (0.3%). E. coli, K. pneumoniae and P. aeruginosa displayed resistance of 1.1%–1.7%, 10.2%24.9%, and 20.2%–27.3%, respectively, to carbapenems. A. baumannii exhibited carbapenem resistance of 66.3%–87.4%. Conclusion: Resistance rates among the nine pathogens in this survey were similar to those reported by Kor-GLASS, although K. pneumoniae showed a higher carbapenem resistance rate. Continuous monitoring and antimicrobial stewardship are necessary to reduce the AMR of major pathogens causing bloodstream infections.