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A megaplasmid family driving dissemination of multidrug resistance in Pseudomonas

Adrian Cazares1, Matthew P Moore2, James P J Hall3

  • 1Institute of Infection and Global Health, University of Liverpool, Liverpool, UK. A.Cazares-Lopez@liverpool.ac.uk.

Nature Communications
|March 15, 2020
PubMed

Insights

Multidrug resistance (MDR) in Pseudomonas aeruginosa is a major health concern. This study characterized large plasmids carrying antibiotic resistance genes, revealing their ancient origins and flexible nature.

Area of Science:

  • Microbiology
  • Genomics
  • Infectious Diseases

Background:

  • Multidrug resistance (MDR) in bacteria poses a significant global health threat.
  • Pseudomonas aeruginosa is a common opportunistic pathogen frequently associated with hospital-acquired infections and MDR.

Purpose of the Study:

  • To characterize the whole genome of multidrug-resistant Pseudomonas aeruginosa clinical isolates.
  • To investigate the structure, evolution, and diversity of large plasmids carrying antibiotic resistance genes.

Main Methods:

  • Whole genome sequencing using long-read technology.
  • Pangenomic and phylogenomic analyses.
  • Comparative analysis of plasmid sequences.

Main Results:

  • Complete sequences of two large (>420 kb) megaplasmids from P. aeruginosa isolates were obtained.
  • These megaplasmids harbor extensive arrays of antibiotic resistance genes within complex and dynamic regions.
  • Phylogenomic analysis revealed an emerging family of these megaplasmids across the Pseudomonas genus, dating back to at least the 1970s.
  • The megaplasmids encode diverse accessory traits and exhibit a highly flexible and diverse accessory genome.

Conclusions:

  • Large, complex megaplasmids are key drivers of multidrug resistance in Pseudomonas aeruginosa.
  • This megaplasmid family is ancient, widespread, and evolves through duplication and recombination.
  • Understanding these mobile genetic elements is crucial for combating antimicrobial resistance.

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