Retraction Note to: Journal of Microbiology (2020) Vol. 58, No. 6, pp. 483–488 https://doi.org/10.1007/s12275-020-9605-6 The Editor-in-Chief has retracted this article at the request of the authors. After publication concerns were raised that prophage sequences do not exist in the genome of the plasmid pNDM-A1 used in this study. The authors have not been able to confirm the existence of prophage sequences in the plasmid. As a result, the Editor-in-Chief no longer has confidence in the results and conclusions presented in this article. Kwan Soo Ko agrees with this retraction. So Yeon Kim has not responded to correspondence from the Editor-in-Chief about this retraction.