1. Sequential Isolation in a Patient of Raoultella planticola and Escherichia coli Bearing a Novel ISCR1 Element Carrying blaNDM-1.
- Author
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Li, Juan, Lan, Ruiting, Xiong, Yanwen, Ye, Changyun, Yuan, Min, Liu, Xinfeng, Chen, Xia, Yu, Deshan, Liu, Bin, Lin, Wenchao, Bai, Xuemei, Wang, Yan, Sun, Qiangzheng, Wang, Yiting, Zhao, Hongqing, Meng, Qiong, Chen, Qiang, Zhao, Ailan, and Xu, Jianguo
- Subjects
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ESCHERICHIA coli , *HOSPITAL patients , *POLYMERASE chain reaction , *NUCLEOTIDE sequence , *BETA lactamases , *GRAM-negative bacteria - Abstract
Background: The gene for New Delhi metallo-β-lactamase 1 (NDM-1) has been reported to be transmitted via plasmids which are easily transferable and capable of wide distribution. We report the isolation of two NDM-1 producing strains and possible in vivo transfer of blaNDM-1 in a patient. Methods: Clinical samples were collected for bacterial culture and antibiotic susceptibility testing from a patient during a 34-day hospitalization. The presence of blaNDM-1 was detected by PCR and sequencing. Plasmids of interest were sequenced. Medical records were reviewed for evidence of association between the administration of antibiotics and the acquisition of the NDM-1 resistance. Results: A NDM-1 positive Raoultella planticola was isolated from blood on the ninth day of hospitalization without administration of any carbapenem antibiotics and a NDM-1 positive Escherichia coli was isolated from feces on the 29th day of hospitalization and eight days after imipenem administration. The blaNDM-1 was carried by a 280 kb plasmid pRpNDM1-1 in R. planticola and a 58 kb plasmid pEcNDM1-4 in E. coli. The two plasmids shared a 4812 bp NDM-1-ISCR1 element which was found to be excisable from the plasmid as a free form and transferrable in vitro to a NDM-1 negative plasmid from E. coli. Conclusion: blaNDM-1 was embedded in an ISCR1 complex class 1 integron as a novel 4812 bp NDM-1-ISCR1 element. The element was found to be able to self excise to become a free form, which may provide a new vehicle for NDM-1 dissemination. This mechanism could greatly accelerate the spread of NDM-1 mediated broad spectrum β-lactam resistance. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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