Prof. dr. ir. Tom Defoirdt

Telephone number: 
+32 9/264 59 76
Faculty staff


  • PhD in Applied Biological Sciences (UGent, 2007)
  • Bio-engineer in cell and gene biotechnology (UGent, 2003)


Working experience

  • Associate professor at CMET (UGent, 2017-present)
  • Postdoctoral researcher at CMET (UGent, 2016-2017)
  • Postdoctoral researcher at Lab of Aquaculture (UGent, 2014-2016)
  • FWO postdoctoral fellow at Lab of Aquaculture & LabMET (UGent, 2007-2014)
  • PhD researcher (IWT grant) at LabMET & Lab of Aquaculture (UGent, 2003-2007)

Research: Bacterial Activity Management (BAM!) group

Research topics

  • Gene regulation in bacteria, bacterial signalling and detection systems (e.g. quorum sensing, sensing of host and environmental cues)
  • Bacterial pathogens, virulence, virulence factors and virulence regulation, host-pathogen interactions
  • Ecology and evolution of bacterial pathogens
  • Management of bacterial activity, antivirulence therapy
  • Aquatic (marine) microbiology, vibrios
  • Blue biotechnology

Selected key publications

  • Defoirdt T 2018. Quorum-sensing systems as targets for antivirulence therapy. Trends in Microbiology 26: 313-328
  • Yang Q, Pande GSJ, Wang Z, Lin B, Rubin RA, Vora GJ, Defoirdt T 2017. Indole signalling and (micro)algal auxins decrease the virulence of Vibrio campbellii, a major pathogen of aquatic organisms. Environmental Microbiology 19: 1987-2004
  • Defoirdt T 2016. Implications of ecological niche differentiaition in marine bacteria for microbial management in aquaculture to prevent bacterial diseases. PLoS Pathogens 12: e1005843
  • Defoirdt T 2016. Specific antivirulence activity, a new concept for reliable screening of virulence inhibitors. Trends in Biotechnology 34: 527-529
  • Yang Q, Defoirdt T 2015. Quorum sensing positively regulates flagellar motility in pathogenic Vibrio harveyi. Environmental Microbiology 17: 960-968
  • Ruwandeepika HAD, Karunasagar I, Bossier P, Defoirdt T 2015. Expression and quorum sensing regulation of type III secretion system genes of Vibrio harveyi during infection of gnotobiotic brine shrimp. PLoS One 10: e0143935
  • Yang Q, Anh NDQ, Bossier P, Defoirdt T 2014. Norepinephrine and dopamine increase motility, biofilm formation, and virulence of Vibrio harveyi. Frontiers in Microbiology 5: 584
  • Natrah FMI, Bossier P, Sorgeloos P, Yusoff FM, Defoirdt T 2014. Significance of microalgal-bacterial interactions for aquaculture. Reviews in Aquaculture 6: 48-61
  • Defoirdt T, Brackman G, Coenye T 2013. Quorum sensing inhibitors: how strong is the evidence? Trends in Microbiology 21: 619-624
  • Defoirdt T 2013. Antivirulence therapy for animal production: filling an arsenal with novel weapons for sustainable disease control. PLOS Pathogens 9: e1003603
  • Defoirdt T, Sorgeloos P 2012. Monitoring of Vibrio harveyi quorum sensing activity in real time during infection of brine shrimp larvae. ISME Journal 6: 2314-2319
  • Defoirdt T, Sorgeloos P, Bossier, P 2011. Alternatives to antibiotics for the control of bacterial disease in aquaculture. Current Opinion in Microbiology 14: 251-258
  • Defoirdt T, Boon N, Bossier P 2010. Can bacteria evolve resistance to quorum sensing disruption? PLoS Pathogens 6: e1000989
  • Defoirdt T, Miyamoto C, Wood TK, Meighen EA, Sorgeloos P, Verstraete W, Bossier P 2007. The natural furanone (5Z)-4-bromo-5-(bromomethylene)-3-butyl-2(5H)-furanone disrupts quorum sensing-regulated gene expression in Vibrio harveyi by decreasing the DNA-binding activity of the transcriptional regulator protein LuxR. Environmental Microbiology 9: 2486-2495
  • Defoirdt T, Halet D, Vervaeren H, Boon N, Van de Wiele T, Sorgeloos P, Bossier P, Verstraete W 2007. The bacterial storage compound poly-ß-hydroxybutyrate protects Artemia franciscana from pathogenic Vibrio campbellii. Environmental Microbiology 9: 445-452


  • Determination of antibacterial and antibiofilm activity of test compounds or organisms
  • Determination of quorum sensing inhibitory activity of test compounds or organisms (AHL, AI-2, CAI-1, indole)
  • Determination of the capability of test compounds or organisms to inhibit virulence factors (flagellar motility, exopolysaccharide production, hemolytic activity, proteolytic activity, siderophore production)
  • Toxicity tests (impact of test compounds on bacterial bioluminescence)


Web presence