A Common Flanking Region in Promiscuous Plasmids Encoding bla(NDM-1) in Klebsiella pneumoniae Isolated in Singapore

作者：Chen Ying Tsong; Siu L Kristopher; Tsai Yu Kuo; Lin Fu Mei; Koh Tse Hsien^*; Chen Jiun Han^*

来源：Microbial Drug Resistance, 2016, 22(2): 109-114.

DOI：10.1089/mdr.2015.0132

Bacteria encoding the New Delhi metallo-beta-lactamase gene (bla(NDM-1)) are regarded as superbugs for their resistance to multiple antibiotics. Plasmids encoding bla(NDM-1) have been observed to be spreading among gram-negative bacteria around the world. Previous studies have demonstrated that multiple modifications of bla(NDM-1)-harboring plasmids might contribute to the spread of the gene. In this study, we analyzed bla(NDM-1)-encoding plasmids from two Klebsiella pneumoniae isolates, DU7433 and DU1301, found to be unrelated by pulsed field gel electrophoresis and multilocus sequencing typing (DU7433: ST14 and DU1301: ST11), and compared them with previously published plasmids. Although strains DU1301, DU7433, and previously published strain DU43320 carried unrelated plasmids, their transconjugants exhibited similar antimicrobial resistance profiles. Transconjugants lacked the resistance to aztreonam, ciprofloxacin, gentamicin, tetracycline, and trimethoprim/sulfamethoxazole when compared with the corresponding clinical isolates. Plasmids pTR1 from DU1301 and pTR2 from DU7433 had completely different plasmid backbones except a short conserved region of bla(NDM-1) and ble flanked with truncated or nontruncated ISAba125 and trpF. The presence of this common region among known bla(NDM-1)-carrying plasmids implies that the dissemination of bla(NDM-1) may be facilitated by mobilization of this conserved immediate region among different plasmids. Control measures should be strictly enforced whenever increasing incidences of epidemiological unrelated strains were identified.

• 出版日期2016-3-1
• 单位中国医科大学