Screening for bio-active and anti-biofilm substances of Bacillus and Paenibacillus species
Acronym: Anti-biofilm
Principal Investigator: Mareike Klinger
Scientific Advisors: Prof. Dr. Mathias Pletz, Dr. Oliwia Makarewicz
Research Area: A Risk Assessment and Sepsis Control
Project Number: A5.1
Duration: 16.09.2011 - 15.09.2014
Module: PhD Fellowship
The Problem
It is suggested that biofilms, sessile and matrix-enclosed communities of bacteria on catheters, devices or tissues, are presented in more than 65 % of all bacterial infections. Biofilms show increased antibiotic tolerance and protection against immune defense thus they are hardly eradicable. The aim of our project is to screen for substances produced by environmental, soil living bacteria exhibiting anti-biofilm activity and to analyze the chemical properties of these compounds.
Results so far
In total, we harvested supernatants of 10 Gram-positive strains (B. amyloliquefaciens (n=5), B. pumilus (n=1), B. licheniformis (n=1) and P. polymyxa (n=3)) cultured under different conditions after 24 hours and 48 hours and performed disc diffusion tests on agar plates treated with multi-drug resistant isolates (E. coli (n=3), K. pneumoniae (n=2), P. auruginosa (n=4), S. aureus (n=3), E. faecalis (n=2) and P. mirabilis (n=1)). We found some supernatants with high activities against human pathogen bacteria. These supernatants were separated by thin-layer chromatography and analyzed using bioautography against the pathogenic indicator strains. Here we found some distinct bands that were highly active against specific bacteria (data not shown). The Gram-positive strains produce bio-active compounds only under distinct conditions and during defined growth phase, thus we are now able to scale up the production of the compounds of interest under optimal conditions. Three of the obtained total supernatants effectively eradicated existing biofilms. Thereby best results were obtained using all three supernatants on biofilms of S. epidermidis. Supernatant of B. licheniformis was also effective against biofilms of E. feacalis and S. aureus MSSA. Supernatant of B. amyloliquefaciens FZB42 suffciently eradicated biofilms of P. aeruginosa PA01 and K. pneumoniae. The active compounds of the supernatants have been extracted by organic solvents and will be now analyzed by LC-MS.
Publications
Sobke A, Klinger M, Hermann B, Sachse S, Nietzsche S, Makarewicz O, Keller PM, Pfister W, Straube E. The urinary antibiotic 5-nitro-8-hydroxyquinoline (nitroxoline) reduces the formation and induces the dispersal of Pseudomonas aeruginosa biofilms by chelation of iron and zinc. Antimicrob Agents Chemother. 2012 Aug 27. [Epub ahead of print].
Mariappan A, Makarewicz O, Chen XH, Borriss R: Two-Component Response Regulator DegU Controls the Expression of Bacilysin in Plant-Growth-Promoting Bacterium Bacillus amyloliquefaciens FZB42. J Mol Microbiol Biotechnol. 2012 Jun 7, 22(2):114-125.
Contact
Tel.: +49 (0)3641 - 9 32 42 27
Universitätsklinikum Jena
Klinik für Innere Medizin II
Abteilung Gastroenterologie, Hepatologie, Infektiologie
Sektion Klinische Infektiologie
Erlanger Allee 101
07747 Jena