Minocycline Susceptibility of Carbapenem-Resistant Acinetobacter baumannii Blood Isolates from a Single Center in Korea: Role of tetB in Resistance

作者：Taeeun Kim, Eun Hee Jeon, Yoon-Kyoung Hong, Jiwon Jung, Min Jae Kim, Heungsup Sung, Mi‐Na Kim, Sung‐Han Kim, Sang‐Ho Choi, Sang‐Oh Lee, Yang Soo Kim, Yong Pil Chong · 发表于：Infection and Chemotherapy · 年份：2025 · DOI：10.3947/ic.2024.0110 · 被引用次数：8 · 研究领域：Antibiotic Resistance in Bacteria

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) represents a devastating and growing global threat, calling for new antibiotic treatments.In Korea, the challenge of treating CRAB is compounded by high nosocomial acquisition rates and limited availability of novel antibiotics.Minocycline, a semisynthetic tetracycline derivative, has been proposed as a therapeutic option for CRAB infections.Nonsusceptibility to minocycline may occur through the efflux pump, TetB.The prevalence of tetB in A. baumannii has increased, along with higher minocycline minimum inhibitory concentrations (MICs).We aimed to evaluate minocycline susceptibility rates in clinical strains of CRAB, and the association between tetB carriage and minocycline susceptibility across different genotypes. Materials and Methods:Representative CRAB blood isolates were collected from Asan Medical Center, Seoul.Minocycline susceptibility was assessed using the Clinical and Laboratory Standards Institute (CLSI) breakpoint (≤4 mg/L) and the proposed pharmacokinetics (PK)/pharmacodynamics (PD) breakpoint (≤1 mg/L).Tigecycline was used as a comparator, and its susceptibility breakpoint for Enterobacterales defined by EUCAST was applied (≤0.5 mg/L).The presence of tetB was detected by PCR, and multilocus sequence typing (MLST) was performed using seven housekeeping genes.Results: Of the 160 CRAB blood isolates, 83.8% were susceptible to minocycline by the CLSI criteria, and 50.6% were PK-PD susceptible by the P...