Detection of Staphylococcus aureus and enterotoxin genotype diversity in Monte Veronese, a Protected Designation of Origin Italian cheese
| Autor: | Franco Dellaglio, Massimiliano Spiazzi, Elena Guglielmini, Sandra Torriani, Franca Rossi, Silvia Sembeni, Albino Poli |
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| Rok vydání: | 2007 |
| Předmět: |
Staphylococcus aureus
Micrococcaceae Genotype Enterotoxin medicine.disease_cause Polymerase Chain Reaction Applied Microbiology and Biotechnology Food safety law.invention Microbiology Enterotoxins Cheese law Multiplex polymerase chain reaction medicine Food microbiology Polymerase chain reaction biology Genetic Variation Multiplex PCR Raw milk biology.organism_classification Food safety Multiplex PCR PDO cheese Real-time PCR detection SE genes diffusion Staphylococcus aureus SE genes diffusion Food Microbiology Real-time PCR detection Staphylococcal Food Poisoning PDO cheese |
| Zdroj: | Letters in Applied Microbiology. 45:529-534 |
| ISSN: | 1472-765X 0266-8254 |
| Popis: | Aims: To evaluate the risk associated with the load and enterotoxigenicity of Staphylococcus aureus in Monte Veronese, a PDO (Protected Designation of Origin) cheese of the Lessinia area (Verona, Italy). Methods and Results: Staphylococcus aureus was quantified by a conventional culture method and by a nucA targeted real-time PCR assay developed in this study. Staphylococcus aureus numbers in cheese were higher than the limit tolerated by the Italian food legislation in 78% instances, according to both detection methods. Multiplex PCR tests for 17 Staph. aureus enterotoxin (SE) genes were applied to nucleic acids extracted from curds, cheeses and Staph. aureus isolates. The SE gene diversity appeared reduced after ripening. The gene encoding SED was found most frequently in dairy samples and the enterotoxin genes ser, sed, seg and sem predominated in the isolates. Conclusions: The occurrence of enterotoxigenic Staph. aureus strains with complex SE genotypes in this PDO cheese at numbers often exceeding the Italian tolerance threshold represents an important risk factor. Significance and Impact of the Study: The high frequency of contamination of Monte Veronese PDO cheese and, expectedly, similar typical productions from raw milk, by enterotoxigenic Staph. aureus imposes a tighter hygienic control in the earlier manufacturing phases. |
| Databáze: | OpenAIRE |
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