title: Arcobacter butzleri in sheep ricotta cheese at retail and related sources of contamination in an industrial dairy plant.
abstract: This study aimed to evaluate Arcobacter species contamination of industrial sheep ricotta cheese purchased at retail and to establish if the dairy plant environment may represent a source of contamination. A total of 32 sheep ricotta cheeses (1.5 kg/pack) packed in a modified atmosphere were purchased at retail, and 30 samples were collected in two sampling sessions performed in the cheese factory from surfaces in contact with food and from surfaces not in contact with food. Seven out of 32 samples (21.9%) of ricotta cheese collected at retail tested positive for Arcobacter butzleri at cultural examination; all positive samples were collected during the same sampling and belonged to the same batch. Ten surface samples (33.3%) collected in the dairy plant were positive for A. butzleri. Cluster analysis identified 32 pulsed-field gel electrophoresis (PFGE) patterns. The same PFGE pattern was isolated from more than one ricotta cheese sample, indicating a common source of contamination, while more PFGE patterns could be isolated in single samples, indicating different sources of contamination. The results of the environmental sampling showed that A. butzleri may be commonly isolated from the dairy processing plant investigated and may survive over time, as confirmed by the isolation of the same PFGE pattern in different industrial plant surface samples. Floor contamination may represent a source of A. butzleri spread to different areas of the dairy plant, as demonstrated by isolation of the same PFGE pattern in different production areas. Isolation of the same PFGE pattern from surface samples in the dairy plant and from ricotta cheese purchased at retail showed that plant surfaces may represent a source of A. butzleri postprocessing contamination in cheeses produced in industrial dairy plants.
authors.affiliation: Department of Veterinary Medicine, University of Sassari, Sassari, Italy.
authors.forename: Christian
authors.initials: C
authors.lastname: Scarano
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Ozzano Emilia, Italy federica.giacometti3@unibo.it.
authors.forename: Federica
authors.initials: F
authors.lastname: Giacometti
authors.affiliation: Department of Agricultural and Food Sciences, Ozzano Emilia, Italy.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Manfreda
authors.affiliation: Department of Agricultural and Food Sciences, Ozzano Emilia, Italy.
authors.forename: Alex
authors.initials: A
authors.lastname: Lucchi
authors.affiliation: Department of Veterinary Medicine, University of Sassari, Sassari, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Pes
authors.affiliation: Department of Veterinary Medicine, University of Sassari, Sassari, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Spanu
authors.affiliation: Department of Veterinary Medicine, University of Sassari, Sassari, Italy.
authors.forename: Enrico Pietro Luigi
authors.initials: EP
authors.lastname: De Santis
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Ozzano Emilia, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Serraino
mesh_terms: D000818:Animals; D020640:Arcobacter / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D002611:Cheese / Q000191:economics / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D005506:Food Contamination / Q000032:analysis* / Q000191:economics; D005511:Food Handling / Q000295:instrumentation; D019649:Food Industry / Q000295:instrumentation*; D008892:Milk / Q000382:microbiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D012756:Sheep