Identification of Plasmid-Encoded sRNAs in a bla NDM-1 -Harboring Multidrug-Resistance Plasmid pNDM-HK in Enterobacteriaceae

• Published in: Frontiers in microbiology Vol. 9; p. 532
• Main Authors: Kong, Hoi-Kuan, Liu, Xuan, Lo, Wai U, Pan, Qing, Law, Carmen O K, Chan, Ting F, Ho, Pak L, Lau, Terrence C K
• Format: Journal Article
• Language: English
• Published: Switzerland 2018
• Subjects: NDM-1; phylogenetic analysis; multidrug-resistance; sRNA; plasmid; pNDM-HK
• ISSN: 1664-302X; 1664-302X

Small RNAs (sRNAs) play significant roles in regulating gene expression post-transcriptionally in response to environmental changes in bacteria. In this work, we identified and characterized six novel sRNAs from an emerging multidrug-resistance (MDR) plasmid pNDM-HK, a New Delhi metallo-β-lactamase 1 gene ( )-carrying IncL/M plasmid that has caused worldwide threat in recent years. These sRNAs are located at different regions of pNDM-HK, such as replication, stability, and variable regions. Moreover, one of the plasmid-encoded sRNAs (NDM-sR3) functions in an Hfq-dependent manner and possibly plays roles in the fitness of pNDM-HK carrying bacteria. In addition, we attempted to construct the phylogenetic tree based on these novel sRNAs and surprisingly, the sRNA-phylogenetic tree provided significant information about the evolutionary pathway of pNDM-HK, including possible gene acquisition and insertion from relevant plasmids. Moreover, the sRNA-phylogenetic tree can specifically cluster the IncM2 type and distinguish it from other IncL/M subtypes. In summary, this is the first study to systematically identify and characterize sRNAs from clinically-isolated MDR plasmids. We believe that these newly found sRNAs could lead to further understanding and new directions to study the evolution and dissemination of the clinically MDR bacterial plasmids.