title: Molecular characterization of Pseudomonas fluorescens isolates involved in the Italian "blue mozzarella" event.
abstract: Between June and September 2010, widespread Italian consumer reports of unusual blue spoilage on fresh dairy products were publicized, resulting in the so-called blue mozzarella event. An inordinately high number of samples from mozzarella and whey cheese products of Italian and German production subsequently tested positive for Pseudomonas fluorescens. The aim of this study was to verify whether a selected P. fluorescens strain was responsible for this apparently unusual event. Molecular characterization of 181 isolated P. fluorescens strains was conducted using a newly optimized pulsed-field gel electrophoresis protocol. Although a high number of pulsotypes was found (132), only four pulsotypes were associated with more than one production plant, and only one German isolate had the same pulsotype as was detected in two Italian plants. This is the only evidence of possible cross-contamination among cheeses from the two countries. The overall results did not support the spread of contamination from German to Italian plants or the presence of one environmental strain that spread in both countries.
authors: S.C. Controllo Alimenti e Igiene delle Produzioni, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, via Bologna, 148-10154 Torino, Italy. chiara.nogarol@izsto.it
authors: C
authors: C
authors: Nogarol
authors: P L
authors: PL
authors: Acutis
authors: D M
authors: DM
authors: Bianchi
authors: C
authors: C
authors: Maurella
authors: S
authors: S
authors: Peletto
authors: S
authors: S
authors: Gallina
authors: D
authors: D
authors: Adriano
authors: F
authors: F
authors: Zuccon
authors: S
authors: S
authors: Borrello
authors: M
authors: M
authors: Caramelli
authors: L
authors: L
authors: Decastelli
mesh_terms: D002611:Cheese / Q000382:microbiology*; D015169:Colony Count, Microbial; D003611:Dairy Products / Q000382:microbiology; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D004783:Environmental Microbiology; D005506:Food Contamination / Q000032:analysis; D005511:Food Handling; D005516:Food Microbiology; D006801:Humans; D007558:Italy; D011551:Pseudomonas fluorescens / Q000235:genetics* / Q000302:isolation & purification