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A Novel Depsipeptide Produced by Paenibacillus alvei 32 Isolated from a Cystic fibrosis Patient

Romain Chevrot1, Sandrine Didelot2, Larissa Van den Bossche3

  • 1Laboratoire Littoral Environnement et Sociétés, LIENSs, Université de La Rochelle, UMR 7266, CNRS, Avenue Michel Crépeau, 17042, Rochelle Cedex 1, France. romain.chevrot01@univ-lr.fr.

Probiotics and Antimicrobial Proteins
|January 20, 2016
PubMed

Insights

Researchers discovered a new antibiotic-producing bacterium, Paenibacillus alvei, in cystic fibrosis (CF) sputum. This bacterium and its novel depsipeptide L molecule show potent activity against dangerous pathogens like MRSA, offering hope for new antimicrobial therapies.

Area of Science:

  • Microbiology
  • Pharmacology
  • Biochemistry

Background:

  • Cystic fibrosis (CF) patients exhibit increased respiratory tract mucus viscosity, impairing mucociliary transport and promoting infections by pathogens like Pseudomonas aeruginosa and Staphylococcus aureus.
  • The CF lung microflora may harbor microorganisms with natural antimicrobial properties to combat these pathogens.

Purpose of the Study:

  • To isolate and identify antibiotic-producing bacteria from CF sputum.
  • To characterize the antimicrobial compounds produced by these isolates.
  • To explore the potential of CF microflora as a source for novel antimicrobial discovery.

Main Methods:

  • Isolation of antibiotic-producing strains from 20 CF sputum samples.
  • Identification of an isolated Gram-positive bacterium as Paenibacillus alvei using API galleries and 16S rRNA gene sequencing.
  • Optimization of a mineral medium (MODT50) for antimicrobial compound production.
  • Purification and characterization of an antimicrobial compound using liquid chromatography-mass spectrometry.

Main Results:

  • Paenibacillus alvei was isolated and demonstrated inhibitory effects against P. aeruginosa, S. aureus, and Klebsiella pneumoniae in co-cultures.
  • The optimized medium's supernatant inhibited growth of various Gram-positive strains, including Methicillin-resistant S. aureus (MRSA).
  • A novel cyclic peptide molecule, depsipeptide L, was purified and characterized, showing activity against S. aureus, Micrococcus luteus, and Pseudomonas stutzeri.

Conclusions:

  • Paenibacillus alvei produces a novel depsipeptide L with significant antimicrobial activity, including against MRSA.
  • This study demonstrates the potential of CF lung microflora as a valuable source for discovering new antimicrobial-producing strains and molecules.
  • The findings suggest a promising avenue for developing new therapeutic strategies against antibiotic-resistant bacterial infections.
Keywords:
Antimicrobial-peptideCystic fibrosisDepsipeptideFusaricidinPaenibacillus alvei

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