SUNGKYUNKWAN UNIVERSITY SCHOOL OF MEDICINE

Acinetobacter baumannii has emerged as an important opportunistic bacterial pathogen responsible for serious infections that are linked with high mortality ranging from 13% to 30% globally. Furthermore, their ability to easily acquire multidrug resistance (MDR) presents an insurmountable obstacle to the treatment of A. baumannii infection. The only antibiotics effective against MDR A. baumannii infections are tigecycline and colistin, but recent studies have increasingly reported the emergence of tigecycline- or colistin-resistant A. baumannii worldwide. Heteroresistance, an existence of resistant subpopulations within a single isogenic susceptible population, to them is also frequently observed in A. baumannii clinical isolates, which contributes to increasing treatment failure.
In this study, we revealed that multiple heteroresistance to tigecycline and colistin is prevalent among A. baumannii clinical isolates and that each resistant subpopulation to tigecycline and colistin exists as an independent event. These findings suggests a rationale for a combined antimicrobial treatment against MDR A. baumannii infection. The combination of tigecycline and colistin eradicated nearly all of the multiple heteroresistant A. baumannii. This may propose an effective therapeutic option for achieving better clinical outcomes against A. baumannii infection.
This study was published in Journal of Biomedical Science (IF: 12.771) in June 2023 (doi: 10.1186/s12929-023-00914-6).