The presence, genetic diversity and behaviour of Listeria monocytogenes in blue-veined cheese rinds during the shelf life

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• 作者：Valentina Bernini ; Benedetta Bottari ; Elena Dalzini ; Elisa Sgarbi ; Camilla Lazzi ; Erasmo Neviani ; Monica Gatti
• 关键词：Listeria monocytogenes ; Blue veined cheese rinds ; AFLP ; Shelf life ; Microbiological challenge testing
• 刊名：Food Control
• 出版年：2013
• 出版时间：December, 2013
• 年：2013
• 卷：34
• 期：2
• 页码：323-330
• 全文大小：1074 K

文摘

Blue-veined cheeses may allow Listeria monocytogenes survival and multiplication due to the biochemical characteristics of the cheese and the growth characteristics of the pathogen. Because of the availability of a considerable number of samples, we wanted this study to take a large view of the microbiota and of the incidence and genetic diversity of L.?monocytogenes in blue-veined cheese rinds. Moreover, we wanted to determine if the pathogen present on the rinds at the end of ripening represented a risk to the consumer if the cheese should exceed the domestic storage limit imposed by for food safety criteria.

The rind microflora showed a high level of heterogeneity, and the incidence of L.?monocytogenes (never found in the paste samples) was 55 % , with an increased presence and concentration associated with a longer ripening time. Amplified Fragment Length Polymorphism (AFLP) was used to characterise L.?monocytogenes isolated from blue-veined cheese rinds and highlighted the heterogeneity among the strains, demonstrating its suitability for studying the biodiversity of the pathogen in this environment. L.?monocytogenes was able to grow during the shelf life of the cheese and was influenced by the refrigeration temperatures and the physicochemical characteristics of the cheese.