Effect of enterocin AS-48 in combination with biocides on planktonic and sessile Listeria monocytogenes

• Published in: Food microbiology 2012-05, Vol.30 (1), p.51-58
• Main Authors: Caballero Gómez, Natacha, Abriouel, Hikmate, Grande, Ma José, Pérez Pulido, Rubén, Gálvez, Antonio
• Format: Article
• Language: English
• Subjects: Bacteriocin; Bacteriocins - pharmacology; Biocide; Biofilm; Biofilms - drug effects; Biofilms - growth & development; Biological and medical sciences; Colony Count, Microbial; Disinfectants - pharmacology; Drug Combinations; Drug Synergism; Food industries; Food microbiology; Fundamental and applied biological sciences. Psychology; Listeria; Listeria monocytogenes - drug effects; Listeria monocytogenes - growth & development; Listeria monocytogenes - pathogenicity; Microbial Sensitivity Tests
• ISSN: 0740-0020; 1095-9998
• DOI: 10.1016/j.fm.2011.12.013

Enterocin AS-48 was tested on a cocktail of Listeria monocytogenes strains in planktonic and sessile states, singly or in combination with biocides benzalkonium chloride, cetrimide, hexadecylpyridinium chloride, didecyldimethylammonium bromide, triclosan, poly-(hexamethylen guanidinium) hydrochloride, chlorhexidine, hexachlorophene, and the commercial sanitizers P3 oxonia and P3 topax 66. Combinations of sub-inhibitory bacteriocin concentrations and biocide concentrations 4 to 10-fold lower than their minimum inhibitory concentrations (MIC) completely inhibited growth of the planktonic listeriae. Inactivation of Listeria in biofilms formed on polystyrene microtiter plates required concentrations of enterocin AS-48 greater than 50μg/ml, and biocide concentrations ten to 100-fold higher. In combination with enterocin AS-48 (25 or 50μg/ml), microbial inactivation increased remarkably for all biocides except P3 oxonia and P3 topax 66 solutions. Polystyrene microtiter plates conditioned with enterocin solutions (0.5–25μg/ml) decreased the adherence and biofilm formation of the L. monocytogenes cell cocktail, avoiding biofilm formation for at least 24h at a bacteriocin concentration of 25μg/ml. ► Sessile L. monocytogenes was much more resistant to biocides and to enterocin AS-48 than its planktonic. ► Enterocin AS-48 potentiated the activity of biocides against planktonic Listeria. ► Enterocin AS-48 potentiated the activity of most biocides against sessile Listeria. ► Addition of AS-48 reduced the biocide concentrations required for complete inactivation of sessile Listeria. ► Enterocin AS-48 decreased the ability of Listeria to form biofilms for 24h.