title: Phosphatidylinositol-specific phospholipase C activity as a marker to distinguish between pathogenic and nonpathogenic Listeria species.
abstract: In this study, 468 Listeria strains were checked for the presence of phosphatidylinositol-specific phospholipase C (PI-PLC) activity by using a simple assay that consisted of overlaying colonies formed on agar plates with L-alpha-phosphatidylinositol as substrate. In this assay, PI-PLC-active colonies show turbid halos around the colonies as a result of the release of insoluble diacylglycerol from the substrate. This activity was detected only in the pathogenic species Listeria monocytogenes and was not present in any of the 167 strains of Listeria seeligeri, Listeria welshimeri, Listeria innocua, Listeria murrayi, and Listeria grayi tested. Hence, screening for PI-PLC activity permits discrimination between pathogenic and nonpathogenic Listeria species. In particular, the hemolytic but nonpathogenic species L. seeligeri can now be separated from the hemolytic and pathogenic species L. monocytogenes and L. ivanovii. The use of this assay will improve the specific detection and/or isolation of pathogenic Listeria species from clinical samples or food enrichment cultures.
authors.affiliation: National Institute of Public Health and Environmental Hygiene, Bilthoven, The Netherlands.
authors.forename: S H
authors.initials: SH
authors.lastname: Notermans
authors.forename: J
authors.initials: J
authors.lastname: Dufrenne
authors.forename: M
authors.initials: M
authors.lastname: Leimeister-Wächter
authors.forename: E
authors.initials: E
authors.lastname: Domann
authors.forename: T
authors.initials: T
authors.lastname: Chakraborty
mesh_terms: D001483:Base Sequence; D015415:Biomarkers; D006460:Hemolysin Proteins / Q000737:chemistry; D008087:Listeria / Q000201:enzymology / Q000235:genetics / Q000472:pathogenicity*; D008969:Molecular Sequence Data; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D010727:Phosphoric Diester Hydrolases / Q000737:chemistry*; D016133:Polymerase Chain Reaction; D014774:Virulence
chemical_list: D015415:Biomarkers; D006460:Hemolysin Proteins; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D043265:Phosphatidylinositol Diacylglycerol-Lyase