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Updated: Jun 7, 2026
08:19
Generating Transposon Insertion Libraries in Gram-Negative Bacteria for High-Throughput Sequencing
Published on: July 7, 2020
Insertion sequence-driven diversification creates a globally dispersed emerging multiresistant subspecies of E.
Helen L Leavis1, Rob J L Willems, Willem J B van Wamel
1Eijkman-Winkler Institute for Medical Microbiology, Infectious Diseases and Inflammation, University Medical Center Utrecht, Utrecht, The Netherlands. hleavis@umcutrecht.nl <hleavis@umcutrecht.nl>
Plos Pathogens
|January 30, 2007
Summary
Multidrug-resistant Enterococcus faecium has become a major hospital pathogen. This study reveals that mobile genetic elements, particularly insertion sequence (IS) elements, drive its adaptation and emergence in healthcare settings.
Area of Science:
- Microbiology
- Genomics
- Evolutionary Biology
Background:
- Enterococcus faecium has transitioned from a commensal to a significant nosocomial pathogen.
- Multidrug resistance and horizontal gene transfer potential of E. faecium pose a major threat.
- Limited understanding of E. faecium evolution and virulence hinders genomic studies.
Purpose of the Study:
- To investigate the genomic basis of Enterococcus faecium evolution and adaptation.
- To identify genetic elements contributing to the emergence of E. faecium as a nosocomial pathogen.
Main Methods:
- Whole-genome microarray hybridization of 97 E. faecium isolates from diverse sources.
- Sequencing of clade-specific inserts to identify mobile elements and genes.
- Bioinformatic analyses including split decomposition and codon adaptation index.
Main Results:
- A distinct clade of E. faecium, containing outbreak and clinical strains, was identified.
- Mobile elements, including insertion sequence (IS) elements, phage genes, and plasmid sequences, were prevalent in the clade.
- Horizontal gene transfer, with IS16 as a prominent insert, was strongly supported as a mechanism for gene acquisition.
- Increased genome plasticity and diversity were observed in clade-specific isolates.
Conclusions:
- Acquisition of IS elements enhances genome plasticity, facilitating niche adaptation in E. faecium.
- A specific subpopulation of E. faecium has evolved enhanced adaptation to the hospital environment.
- The findings provide insights into the global emergence and evolution of E. faecium as a critical pathogen.
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