title: Comparison of the cell surface properties and growth characteristics of Listeria monocytogenes and Listeria innocua.
abstract: Growth kinetics and physicochemical surface properties were compared for three Listeria strains with differing degrees of virulence: L. monocytogenes LO28; its isogenic, nonhemolytic mutant L. monocytogenes Bof415; and a nonvirulent species, L. innocua (strain Lin9). The influences of growth stage (mid-exponential phase, early stationary phase, and mid-stationary phase) and culture temperature (20 and 37 degrees C) were assessed by determining the electrical properties and the hydrophobic-hydrophilic and Lewis acid-base characteristics of the three strains. L. innocua, although taxonomically very similar to L. monocytogenes, exhibited physicochemical surface properties that differed significantly from those of L. monocytogenes LO28 and L. monocytogenes Bof415. Indeed, under our experimental conditions, L. innocua cells presented a more marked electronegative character (particularly when cultured at 20 degrees C), as well as greater variability in their Lewis acid-base characteristics as a function of temperature and growth stage. Furthermore, the growth kinetics of the three strains revealed the onset of a decay phase after 16 h of culture at 37 degrees C for the L monocytogenes Bof415 mutant. All of these results demonstrate that under our experimental conditions, the growth and/or physicochemical characteristics of the slightly pathogenic or nonpathogenic Listeria strains (Bof415 and Lin9) differed from those of the virulent strain (L. monocytogenes LO28). Consequently, the use of Listeria strains recognized as nonvirulent appeared to provide a model that was not fully suitable for simulating the bioadhesive behavior of the pathogenic strains involved in foodborne diseases.
authors.affiliation: Unité de Recherche en Bioadhésion et Hygiène des Matériaux, Institut National de la Recherche Agronomique, Massy, France. meylheuc@massy.inra.fr
authors.forename: Thierry
authors.initials: T
authors.lastname: Meylheuc
authors.forename: Ines
authors.initials: I
authors.lastname: Giovannacci
authors.forename: Romain
authors.initials: R
authors.lastname: Briandet
authors.forename: Marie-Noëlle
authors.initials: MN
authors.lastname: Bellon-Fontaine
mesh_terms: D001422:Bacterial Adhesion; D005516:Food Microbiology; D007700:Kinetics; D008087:Listeria / Q000254:growth & development / Q000502:physiology*; D008089:Listeria monocytogenes / Q000254:growth & development / Q000502:physiology*; D013696:Temperature; D014774:Virulence