Extracellular DNA Chelates Cations and Induces Antibiotic Resistance in Pseudomonas aeruginosa Biofilms
2008

How DNA in Biofilms Makes Bacteria Resistant to Antibiotics

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Author Information

Author(s): Heidi Mulcahy, Laetitia Charron-Mazenod, Shawn Lewenza, Michael S. Gilmore

Primary Institution: University of Calgary

Hypothesis

Does extracellular DNA contribute to antibiotic resistance in Pseudomonas aeruginosa biofilms?

Conclusion

Extracellular DNA in biofilms induces antibiotic resistance by creating a cation-limited environment that activates specific resistance genes.

Supporting Evidence

  • Extracellular DNA was shown to have antimicrobial activity against Pseudomonas aeruginosa.
  • DNA chelation of cations was confirmed to induce resistance to cationic antimicrobial peptides.
  • Biofilms enriched with DNA exhibited significantly higher resistance to antibiotics compared to those without.

Takeaway

Bacteria in biofilms can become super strong against medicines because of DNA that helps them hold onto important minerals. This makes it harder to kill them.

Methodology

The study involved examining the effects of extracellular DNA on Pseudomonas aeruginosa growth and antibiotic resistance through various assays and gene expression measurements.

Limitations

The study primarily focused on one bacterial species and may not generalize to all biofilm-forming bacteria.

Digital Object Identifier (DOI)

10.1371/journal.ppat.1000213

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