Degradation intermediates of polyhydroxy butyrate inhibits phenotypic expression of virulence factors and biofilm formation in luminescent Vibrio sp. PUGSK8

摘要: Luminescent vibrios are ubiquitous in the marine environment and causative agents of vibriosis mass mortality many aquatic animals. In environments, treatments cannot be limited to diseased population alone, therefore treatment entire system is only possible approach. Thus, use antibiotics treat part infected animals requires a dose based on biomass, which results uninfected as well non-target normal microbial flora. A method anti-virulence or quorum quenching has recently been proposed an effective strategy for Polyhydroxy butyrates (PHB) bacterial storage molecules, accumulate cells under nutritional stress. The degradation PHB releases short-chain β-hydroxy butyric acid, may act anti-infective molecule. To date, there very information potential mechanisms involving PHB. this study, we aim examine effect inhibition virulence cascade Vibrio such biofilm formation, luminescence, motility behaviour, haemolysin sensing. luminescent PUGSK8, tentatively identified campbellii PUGSK8 was tested vitro production extracellular factors then established shrimp pathogen vivo challenge experiments. ability form biofilms formation 96-well microtitre-plate assay system. behaviour evaluated using twitching, swimming swarming plate assays. Reporter strains Chromobacterium violaceum CV026 Agrobacterium tumefaciens were used detect quorum-sensing molecules. Gas chromatography-mass spectrometry spectral analysis performed elucidate fragmentation pattern structure N-hexanoyl homoserine lactone. depolymerase activity quantified amount enzyme solution hydrolyse 1 μg per min. An experiment gnotobiotic Artemia assay. Of 27 isolates tested, strain selected target-specific assays high intensity luminescence factors. detected include sensing production. Thus inhibition/degradation would approach contain infections report, demonstrate that intermediate effectively inhibits N-acyl-homoserine lactone (AHL)-mediated pathway PUGSK8. Interestingly, growth remains unaffected presence PHB, with being media. release intermediates molecule targets species/strain-specific could prove alternative antimicrobial control pathogenesis Vibrio, thereby help outbreaks systems.