RT Journal Article SR Electronic(1) A1 Ko, Jae-Hoon A1 Baek, Jin Yang A1 Peck, Kyong Ran A1 Cho, Sun Young A1 Ha, Young Eun A1 Kim, So Hyun A1 Huh, Hee Jae A1 Lee, Nam Yong A1 Kang, Cheol-In A1 Chung, Doo Ryeon A1 Song, Jae-HoonYR 2017 T1 Discrepant susceptibility to gentamicin despite amikacin resistance in Klebsiella pneumoniae by VITEK 2 represents false susceptibility associated with the armA 16S rRNA methylase gene JF Journal of Medical Microbiology, VO 66 IS 10 SP 1448 OP 1450 DO https://doi.org/10.1099/jmm.0.000583 PB Microbiology Society, SN 1473-5644, AB Because we experienced gentamicin failure in Klebsiella pneumoniae bacteraemia that was susceptible to gentamicin despite amikacin resistance, as determined by VITEK 2, we evaluated the true susceptibility and mechanism of resistance. We screened 2818 K. pneumoniae isolates during a 1-year period at a university hospital and reviewed anti-microbial susceptibility reports using the VITEK 2 system. The minimum inhibitory concentration was substantiated by broth microdilution (BMD), and the presence of 16S rRNA methylase genes and aminoglycoside-modifying enzymes was also investigated. A total of 131 amikacin-resistant isolates from 19 patients were gentamicin non-resistant according to the VITEK 2 system. Among these, we were able to collect isolates from 12 patients (63.2 %), and a single isolate from each patient was tested. Eleven of the gentamicin non-resistant isolates (91.7 %) showed high-level resistance to both amikacin and gentamicin by BMD in association with the armA gene. Gentamicin is not an adequate treatment option for amikacin-resistant K. pneumoniae, even if VITEK 2 reports susceptibility., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.000583