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Use of bacteriophage endolysin EL188 and outer membrane permeabilizers against Pseudomonas aeruginosa

Y Briers1, M Walmagh, R Lavigne

  • 1Division of Gene Technology, Department of Biosystems, Katholieke Universiteit Leuven, Leuven, Belgium.

Journal of Applied Microbiology
|January 19, 2011
PubMed
Abstract

Insights

Ethylene diamine tetraacetic acid disodium salt dihydrate (EDTA) effectively enhances bacteriophage endolysin EL188 activity against Pseudomonas aeruginosa. This combination inactivates the bacteria by up to 4 log units in 30 minutes, showing enzybiotics

Area of Science:

  • Microbiology
  • Biotechnology
  • Antimicrobial Research

Background:

  • Bacteriophage endolysins are potent antimicrobials but their efficacy against Gram-negative bacteria is limited by the outer membrane.
  • Pseudomonas aeruginosa is a multi-resistant pathogen necessitating novel inactivation strategies.

Purpose of the Study:

  • To identify and assess an effective outer membrane permeabilizer for use with endolysin EL188.
  • To evaluate the combined efficacy of EL188 and permeabilizers against multi-resistant Pseudomonas aeruginosa.

Main Methods:

  • Tested combinations of endolysin EL188 with various outer membrane permeabilizing agents.
  • Analyzed outer membrane permeabilization using N-phenylnaphtylamine and a fluorescent reporter protein.
  • Performed cell lysis assays and antibacterial assays to quantify bacterial inactivation.

Main Results:

  • Ethylene diamine tetraacetic acid disodium salt dihydrate (EDTA) was identified as a suitable outer membrane permeabilizer.
  • The combination of 10 mmol/L EDTA and 50 μg/mL endolysin EL188 achieved 3.01–4.27 log unit inactivation of P. aeruginosa within 30 minutes.
  • Increasing EL188 concentration to 250 μg/mL further enhanced inactivation of highly resistant strains.

Conclusions:

  • EDTA is the optimal agent to combine with endolysin EL188 for P. aeruginosa inactivation.
  • This combination reduces P. aeruginosa by up to 4 log units in 30 minutes.
  • Bacteriophage endolysins (enzybiotics) show potential for treating Gram-negative bacterial infections.

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