Intracellular Transposition of Mobile Genetic Elements Associated with the Colistin Resistance Gene mcr-1
Issued Date
2023-01-01
Resource Type
eISSN
21650497
Scopus ID
2-s2.0-85148114202
Pubmed ID
36511714
Journal Title
Microbiology Spectrum
Volume
11
Issue
1
Rights Holder(s)
SCOPUS
Bibliographic Citation
Microbiology Spectrum Vol.11 No.1 (2023)
Suggested Citation
Goodman R.N., Tansirichaiya S., Brouwer M.S.M., Roberts A.P. Intracellular Transposition of Mobile Genetic Elements Associated with the Colistin Resistance Gene mcr-1. Microbiology Spectrum Vol.11 No.1 (2023). doi:10.1128/spectrum.03278-22 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/81888
Title
Intracellular Transposition of Mobile Genetic Elements Associated with the Colistin Resistance Gene mcr-1
Author's Affiliation
Other Contributor(s)
Abstract
Mobile colistin resistance (mcr) genes are often located on conjugative plasmids, where their association with insertion sequences enables intercellular and intracellular dissemination throughout bacterial replicons and populations. Multiple mcr genes have been discovered in every habitable continent, in many bacterial species, on both plasmids and integrated into the chromosome. Previously, we showed the intercellular transfer of mcr-1 on an IncI1 plasmid, pMCR-E2899, between strains of Escherichia coli. Characterizing the intracellular dynamics of mcr-1 transposition and recombination would further our understanding of how these important genes move through bacterial populations and whether interventions can be put in place to stop their spread. In this study, we aimed to characterize transfer events from the mcr-1-containing transposon Tn7511 (ISApl1-mcr-1-pap2-ISApl1), located on plasmid pMCR-E2899, using the pBACpAK entrapment vector. Following the transformation of pBACpAK into our DH5a-Azir/pMCR-E2899 transconjugant, we captured ISApl1 in pBACpAK multiple times and, for the first time, observed the ISApl1-mediated transfer of the mcr-1 transposon (Tn7511) into the chromosome of E. coli DH5a. Whole-genome sequencing allowed us to determine consensus insertion sites of ISApl1 and Tn7511 in this strain, and comparison of these sites allowed us to explain the transposition events observed. These observations reveal the consequences of ISApl1 transposition within and between multiple replicons of the same cell and show mcr-1 transposition within the cell as part of the novel transposon Tn7511. IMPORTANCE By analyzing the intracellular transfer of clinically relevant transposons, we can understand the dissemination and evolution of drug resistance conferring mobile genetic elements (MGEs) once a plasmid enters a cell following conjugation. This knowledge will help further our understanding of how these important genes move through bacterial populations. Utilizing the pBACpAK entrapment vector has allowed us to determine the mobility of the novel mcr-1-containing transposon Tn7511.