Lactocin AL705 as quorum sensing inhibitor to control Listeria monocytogenes biofilm formation

MELIÁN, CONSTANZA; SEGLI F,; RODRIGO GONZALEZ; VIGNOLO, G; CASTELLANO P

JOURNAL OF APPLIED MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2019

1364-5072

AbstractAimsThe control of Listeria monocytogenes biofilm formation using lactocin AL705 bacteriocin at sub‐MICs through an anti‐quorum sensing strategy, was preliminarily investigated.Methods and ResultsThe screening for biofilm formation of different Listeria species at 10 °C allowed selecting L. monocytogenes FBUNT for its use as biofilm producer. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of lactocin AL705 purified extract against the pathogen was determined. Bacteriocin sub‐MICs were used to evaluate biofilm reduction. Concentrations between 2·5 to 20 AU ml−1 of lactocin AL705 produced significant decreases in biofilm formation without affecting the growth of the pathogen after 3 days of incubation. When bacteriocin concentrations (5‐20 AU ml−1) were investigated as quorum sensing (QS) inhibitors using V. harveyi as reporter strain, a significant reduction of luminescence by lactocin AL705 (20 AU ml−1) was observed. Even when L. monocytogenes produced AI‐2 like molecules as recognized by the reporter strain, bacteriocins did not interfere with this compound.ConclusionAnti‐listerial lactocin AL705 used to disrupt QS through a signal molecule inactivation was able to control L. monocytogenes FBUNT biofilm formation. Other molecule(s) different from the AI‐2 involved during biofilm formation could be acting as target of the bacteriocin.Significance and Impact of the StudyThe use of bacteriocins derived from food‐grade microorganisms as a QS inhibition represents an effective strategy to control pathogens as well as an environmentally‐friendly sanitation method to mitigate post‐processing food contamination.