Presence and molecular characterization of the major serovars of Listeria monocytogenes in ten Sardinian fermented sausage processing plants.
The aim of the present study was to investigate the occurrence of Listeria monocytogenes in ten Sardinian fermented sausage processing plants. A total of 230 samples were collected and 40 L. monocytogenes isolates were obtained and subjected to serotyping and investigated for the presence of ten virulence-associated genes using multiplex PCR assays. The isolates were further subjected to PFGE and investigated for their adhesion abilities in polystyrene microtiter plates. L. monocytogenes was found in 6% of food contact surfaces, in sausages at the end of acidification (3%) and ripening (8%). Serotyping revealed the presence of four serovars: 1/2c (37.5%), 1/2b (27.5%), 4b (22.5%) and 1/2a (12.5%). All virulence-associated genes were detected in 67.5% of the isolates. Isolates from processing environment, semi-processed and finished products showed high pulsotype diversity and the majority of isolates presented weak adhesion capability. The detection of the pathogen in fermented sausages confirms the ability of L. monocytogenes to overcome the hurdles of the manufacturing process.
Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy. Electronic address: dmeloni@uniss.it.
Domenico
D
Meloni
Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy.
Simonetta Gianna
SG
Consolati
Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy.
Roberta
R
Mazza
Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy.
Anna
A
Mureddu
Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy.
Federica
F
Fois
Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy.
Francesca
F
Piras
Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy.
Rina
R
Mazzette
D000818:Animals; D001422:Bacterial Adhesion; D004032:Diet; D016521:Electrophoresis, Gel, Pulsed-Field; D005285:Fermentation; D005516:Food Microbiology; D005798:Genes, Bacterial; D006801:Humans; D007558:Italy; D008089:Listeria monocytogenes / Q000235:genetics*; D008461:Meat Products / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D011137:Polystyrenes; D065288:Serogroup; D012703:Serotyping; D013552:Swine; D014774:Virulence / Q000235:genetics*
D011137:Polystyrenes
Adhesion ability; Fermented sausage; Listeria monocytogenes; Pathogenic profile; Pulsotype; Serovar