title: Microbial ecology of Gorgonzola rinds and occurrence of different biotypes of Listeria monocytogenes.
abstract: In this study we investigated the microbiota of Gorgonzola rinds and maturing shelf swabs collected in 5 different maturing cellars in the Northwest part of Italy, in association with the detection and characterization of Listeria monocytogenes. Culture-dependent and -independent methods were performed in order to profile the main microbial populations present on the rinds and in the maturing shelves and species-specific PCR and Pulsed Field Gel Electrophoresis (PFGE) were used to identify and type L. monocytogenes isolates. The microflora was predominated by lactic acid bacteria and coagulase negative cocci, while enterococci and yeasts were very variable between the samples. Arthrobacter sp., Carnobacterium sp., Staphylococcus sp. and Brevibacterium linens, as bacteria, and Debaryomyces hansenii, as yeast, were detected by Denaturing Gradient Gel Electrophoresis (DGGE). Cluster analysis of the DGGE profiles clearly highlighted a cellar-specific microflora. L. monocytogenes was isolated in 11.1% of the rinds and 29.4% of the swabs and the molecular characterization of the isolates suggests a route of contamination from the maturing shelves to the rinds. No correlation was found between DGGE profiles and presence or absence of L. monocytogenes.
authors.affiliation: Di.Va.P.R.A., University of Turin, Italy. lucasimone.cocolin@unito.it
authors.forename: Luca
authors.initials: L
authors.lastname: Cocolin
authors.forename: Daniele
authors.initials: D
authors.lastname: Nucera
authors.forename: Valentina
authors.initials: V
authors.lastname: Alessandria
authors.forename: Kalliopi
authors.initials: K
authors.lastname: Rantsiou
authors.forename: Paola
authors.initials: P
authors.lastname: Dolci
authors.forename: Maria Auxilia
authors.initials: MA
authors.lastname: Grassi
authors.forename: Sara
authors.initials: S
authors.lastname: Lomonaco
authors.forename: Tiziana
authors.initials: T
authors.lastname: Civera
mesh_terms: D001419:Bacteria / Q000302:isolation & purification*; D002611:Cheese / Q000382:microbiology*; D004586:Electrophoresis; D005516:Food Microbiology; D014644:Genetic Variation; D006801:Humans; D008089:Listeria monocytogenes / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D015003:Yeasts / Q000302:isolation & purification*