Annals of Clinical Microbiology, The official Journal of the Korean Society of Clinical Microbiology


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pISSN 2288-0585 eISSN 2288-6850

Role of Efflux Pump Gene adeIJK to Multidrug Resistance in Acinetobacter baumannii Clinical Isolates

Original article

Annals of Clinical Microbiology (Ann Clin Microbiol) 2020 March, Volume 23, Issue 1, pages 45-54.

Role of Efflux Pump Gene adeIJK to Multidrug Resistance in Acinetobacter baumannii Clinical Isolates

Ji Ae Choi1, Choon-Mee Kim2, Sook-Jin Jang3, Seong-Sik Cho4, Chul Ho Jang5, Young-Jin Ko3, SeongHo Kang3, Geon Park3
1Division of Antimicrobial Resistance, Center for Infectious Diseases Research, Korea National Institute of Health, KCDC, Cheongju, 2Premedical Science, 3Department of Laboratory Medicine, College of Medicine, 4Department of Laboratory Medicine, Chosun University Hospital, Gwangju, 5Department of Otolaryngology, Chonnam National University Medical School, Gwangju, Republic of Korea.


Background: The emergence of multidrug-resistant

 as a nosocomial pathogen is one of the major public health problems. The aim of this study was to evaluate the role of an efflux pump gene adeJ for the multidrug resistance of A. baumannii clinical isolates.

Methods: Two groups (MDRAB and SAB) of A. baumannii clinical isolates were studied. The SAB group consisted of strains that did not meet the criteria of MDRAB and were susceptible to more categories of antibiotics than MDRAB. Antimicrobial susceptibility results obtained by VITEKⅡ system were used in data analysis and bacterial group allocation. We performed realtime reverse transcription PCR to determine relative expression of adeJ. We compared relative expression of adeJ in comparison groups by considering two viewpoints: i) MDRAB and SAB groups and ii) susceptible and non-susceptible groups for each antibiotic used in this study.

Results: The mean value of relative expression of adeJ of MDRAB and SAB groups was 1.4 and 0.92, respectively, and showed significant difference (P=0.002). The mean values of relative expression of adeJ of susceptible and non-susceptible groups to the antibiotics cefepime, ceftazidime, ciprofloxacin, imipenem, meropenem, tigecycline, piperacillin/ tazobactam, ticarcillin/clavulanic acid, trimethoprim/sulfamethoxazole, piperacillin, and gentamicin showed statistically significant differences.

Conclusion: The overexpression of adeIJK might contribute to the multi-drug resistance in A. baumannii clinical isolates. Further, the overexpression of adeIJK might be one of the factors contributing to the resistance to numerous antibiotics.


Acinetobacter baumannii, adeJ gene, Efflux, Multidrug resistance