title: Virstatin inhibits biofilm formation and motility of Acinetobacter baumannii.
abstract: BACKGROUND
  Acinetobacter baumannii has emerged as an opportunistic nosocomial pathogen causing infections worldwide. One reason for this emergence is due to its natural ability to survive in the hospital environment, which may be explained by its capacity to form biofilms. Cell surface appendages are important determinants of the A. baumannii biofilm formation and as such constitute interesting targets to prevent the development of biofilm-related infections. A chemical agent called virstatin was recently described to impair the virulence of Vibrio cholerae by preventing the expression of its virulence factor, the toxin coregulated pilus (type IV pilus). The objective of this work was to investigate the potential effect of virstatin on A. baumannii biofilms.
  
  
  RESULTS
  After a dose-response experiment, we determined that 100 μM virstatin led to an important decrease (38%) of biofilms formed by A. baumannii ATCC17978 grown under static mode. We demonstrated that the production of biofilms grown under dynamic mode was also delayed and reduced. The biofilm susceptibility to virstatin was then tested for 40 clinical and reference A. baumannii strains. 70% of the strains were susceptible to virstatin (with a decrease of 10 to 65%) when biofilms grew in static mode, whereas 60% of strains respond to the treatment when their biofilms grew in dynamic mode. As expected, motility and atomic force microscopy experiments showed that virstatin acts on the A. baumannii pili biogenesis.
  
  
  CONCLUSIONS
  By its action on pili biogenesis, virstatin demonstrated a very promising antibiofilm activity affecting more than 70% of the A. baumannii clinical isolates.
authors.forename: Yassine
authors.initials: Y
authors.lastname: Nait Chabane
authors.forename: Mohamed Ben
authors.initials: MB
authors.lastname: Mlouka
authors.forename: Stéphane
authors.initials: S
authors.lastname: Alexandre
authors.forename: Marion
authors.initials: M
authors.lastname: Nicol
authors.forename: Sara
authors.initials: S
authors.lastname: Marti
authors.forename: Martine
authors.initials: M
authors.lastname: Pestel-Caron
authors.forename: Jordi
authors.initials: J
authors.lastname: Vila
authors.forename: Thierry
authors.initials: T
authors.lastname: Jouenne
authors.affiliation: Normandie University, Caen, France. emmanuelle.de@univ-rouen.fr.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Dé
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000502:physiology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D002087:Butyrates / Q000494:pharmacology*; D010861:Fimbriae, Bacterial / Q000187:drug effects; D008124:Locomotion / Q000187:drug effects*; D018625:Microscopy, Atomic Force; D053644:Naphthalimides / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D002087:Butyrates; D053644:Naphthalimides; C505381:virstatin