Prevalence, Antimicrobial Susceptibility, and Carbapenem Resistance of Non-baumannii Acinetobacter Species in Three Korean Hospitals

다국어 초록 (Multilingual Abstract)

Non-baumannii Acinetobacter species are increasingly prevalent as opportunistic pathogens in the hospitals worldwide. However, the current information of epidemiology and antimicrobial susceptibility of non-baumannii Acinetobacter species is limited in Korea. This study investigated the species distribution, antimicrobial susceptibility, and carbapenem resistance mechanisms of 65 nonbaumannii Acinetobacter isolates from three Korean hospitals during 2017 to 2020. Sixteen different Acinetobacter species were identified. Among them, A.
ursingii (n = 16), A. junii (n = 11), and A. nosocomialis (n = 9) were prevalent, accounting for 55.4% of the isolates. A half (50.8%) of non-baumannii Acinetobacter isolates were susceptible to all antimicrobial agents tested. Non-baumannii Acinetobacter isolates exhibited the highest resistance rate to piperacillin (26.2%), whereas no isolates were resistant to minocycline and tigecycline. Seven isolates were resistant to carbapenems by the production of carbapenemases. Ambler class B (blaNDM-1 and blaVIM-2) and class D carbapenemase genes (blaOXA-23, blaOXA-58, blaOXA-211, and blaOXA-213) were detected. Three isolates carried two or more carbapenemase genes. One A. calcoaceticus isolate co-carried blaVOXA-58, blaOXA-213, and blaNDM-1. In conclusion, this study provides new insights into antimicrobial susceptibility and carbapenem resistance mechanisms of Korean non-baumannii Acinetobacter species. The spread of carbapenem resistance genes should be carefully monitored among non-baumannii Acinetobacter species.