Investigating the role of matrix components in protection of Burkholderia cepacia complex biofilms against tobramycin.
BACKGROUND
Burkholderia cepacia complex (Bcc) organisms produce a wide variety of potential virulence factors, including exopolysaccharides (EPS), and exhibit intrinsic resistance towards many antibiotics. In the present study we investigated the contribution of Bcc biofilm matrix components, including extracellular DNA, cepacian and poly-β-1,6-N-acetylglucosamine, to tobramycin susceptibility.


METHODS
The in vitro bactericidal activity of tobramycin in combination with recombinant human DNase (rhDNase), NaClO and dispersin B was tested against Bcc biofilms.


RESULTS
EPS degradation by NaClO pretreatment and specific PNAG degradation by dispersin B significantly increased the bactericidal effect of tobramycin towards some of the Bcc biofilms tested, including the strains of Burkholderia cenocepacia, B. cepacia and Burkholderia metallica. The presence of rhDNase during biofilm treatment and/or development had no influence on tobramycin activity.


CONCLUSIONS
These results suggest that EPS play a role in tobramycin susceptibility of Bcc biofilms and that matrix degrading combination therapy could improve treatment of Bcc biofilm infections.
Laboratory of Pharmaceutical Microbiology, Ghent University, Harelbekestraat 72, 9000 Ghent, Belgium.
Anne-Sophie
AS
Messiaen
Laboratory of Pharmaceutical Microbiology, Ghent University, Harelbekestraat 72, 9000 Ghent, Belgium.
Hans
H
Nelis
Laboratory of Pharmaceutical Microbiology, Ghent University, Harelbekestraat 72, 9000 Ghent, Belgium. Electronic address: Tom.Coenye@Ugent.be.
Tom
T
Coenye
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D018441:Biofilms / Q000254:growth & development*; D019121:Burkholderia Infections / Q000188:drug therapy / Q000382:microbiology*; D016956:Burkholderia cepacia / Q000187:drug effects* / Q000378:metabolism / Q000472:pathogenicity; D003550:Cystic Fibrosis / Q000382:microbiology*; D004269:DNA, Bacterial / Q000378:metabolism; D024881:Drug Resistance, Bacterial / Q000502:physiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D014031:Tobramycin / Q000494:pharmacology*; D014774:Virulence; D037521:Virulence Factors / Q000378:metabolism; D047071:beta-Glucans / Q000378:metabolism
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D011135:Polysaccharides, Bacterial; D037521:Virulence Factors; D047071:beta-Glucans; C487212:cepacian; C505465:poly-N-acetyl-1-6-glucosamine; D014031:Tobramycin
Biofilm; Burkholderia cepacia complex; Cepacian; Matrix; PNAG; Tobramycin