Unsaturated Fatty Acids Affect Quorum Sensing Communication System and Inhibit Motility and Biofilm Formation of Acinetobacter baumannii

• Published in: International journal of molecular sciences Vol. 19; no. 1; p. 214
• Main Authors: Nicol, Marion, Alexandre, Stéphane, Luizet, Jean-Baptiste, Skogman, Malena, Jouenne, Thierry, Salcedo, Suzana P, Dé, Emmanuelle
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 10-01-2018; MDPI
• Subjects: Acinetobacter baumannii; Adhesion tests; Antibiotic resistance; Antibiotics; Atomic force microscopy; Bacteria; Biofilms; Chemical communication; Cholera; Clinical isolates; Communications systems; Fatty acids; Hospitals; Hydrophobicity; Interfacial properties; Life Sciences; Microbiology and Parasitology; Motility; Multidrug resistance; N-Acyl homoserine lactone; Organic compounds; Pathogens; Pellicle; Pili; Virulence; palmitoleic acid; myristoleic acid; quorum sensing; biofilm; pellicle
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms19010214

The increasing threat of
as a nosocomial pathogen is mainly due to the occurrence of multidrug-resistant strains that are associated with the real problem of its eradication from hospital wards. The particular ability of this pathogen to form biofilms contributes to its persistence, increases antibiotic resistance, and promotes persistent/device-related infections. We previously demonstrated that virstatin, which is a small organic compound known to decrease virulence of
via an inhibition of T4-pili expression, displayed very promising activity to prevent
biofilm development. Here, we examined the antibiofilm activity of mono-unsaturated chain fatty acids, palmitoleic (PoA), and myristoleic (MoA) acids, presenting similar action on
virulence. We demonstrated that PoA and MoA (at 0.02 mg/mL) were able to decrease
ATCC 17978 biofilm formation up to 38% and 24%, respectively, presented a biofilm dispersing effect and drastically reduced motility. We highlighted that these fatty acids decreased the expression of the regulator
from the LuxIR-type quorum sensing (QS) communication system AbaIR and consequently reduced the
-acyl-homoserine lactone production (AHL). This effect can be countered by addition of exogenous AHLs. Besides, fatty acids may have additional non-targeted effects, independent from QS. Atomic force microscopy experiments probed indeed that PoA and MoA could also act on the initial adhesion process in modifying the material interface properties. Evaluation of fatty acids effect on 22 clinical isolates showed a strain-dependent antibiofilm activity, which was not correlated to hydrophobicity or pellicle formation ability of the tested strains, and suggested a real diversity in cell-to-cell communication systems involved in
biofilm formation.