中文摘要：本研究的目的是：（1）追踪烧烤奶酪制作过程中金黄色葡萄球菌的感染情况，（2）建立一种可持续抑制金黄色葡萄球菌的方法，在不改变传统制作工艺的情况下降低烧烤奶酪制作过程中金黄色葡萄球菌的污染。研究采用逐步盲法分析法，利用葡萄球菌蛋白A基因分型、DNA微阵列、脉冲场凝胶电泳等技术追踪了4个不同生产阶段金黄色葡萄球菌的污染情况；并筛选出一种新的发酵剂，利用奶酪产量模型评估该发酵剂对金黄色葡萄球菌生长的抑制作用等。结果表明：试验追踪到根植于生产者鼻腔和前臂的2种肠毒性金黄色葡萄球菌（t073/CC45 和t282/CC45），筛选出的新的发酵剂在不影响奶酪外观和不改变技术条件的情况下能有效抑制金黄色葡萄球菌的生长。
外文摘要：Staphylococcal food poisoning is one of the most prevalent causes of foodborne intoxication worldwide. It is caused by ingestion of enterotoxins formed by Staphylococcus aureus during growth in the food matrix. Following a recall of barbecue cheese due to the detection of staphylococcal enterotoxins in Switzerland in July 2015, we analyzed the production process of the respective dairy. Although most cheese-making processes involve acidification to inhibit the growth of pathogenic bacteria, barbecue cheese has to maintain a pH >6.0 to prevent undesired melting of the cheese. In addition, the dairy decided to retain the traditional manual production process of the barbecue cheese. In this study, therefore, we aimed to (1) trace Staph. aureus along the barbecue cheese production process, and (2) develop a sustainable strategy to inhibit growth of Staph. aureus and decrease the risk of staphylococcal food poisoning without changing the traditional production process. To this end, we traced Staph. aureus in a step-wise blinded process analysis on 4 different production days using spa (Staphylococcus protein A gene) typing, DNA microarray profiling, and pulsed field gel electrophoresis analysis. We subsequently selected a new starter culture and used a model cheese production including a challenge test assay to assess its antagonistic effect on Staph. aureus growth, as well as its sensory and technological implications. We detected Staph. aureus in 30% (37/124) of the collected samples taken from the barbecue cheese production at the dairy. This included detection of Staph. aureus in the final product on all 4 production days, either after enrichment or using quantitative detection. We traced 2 enterotoxigenic Staph. aureus strains (t073/CC45 and t282/CC45) colonizing the nasal cavity and the forearms of the cheesemakers to the final product. In the challenge test assay, we were able to show that the new starter culture inhibited growth of Staph. aureus while meeting the sensory and technological requirements of barbecue cheese production.
外文关键词：Staphylococcus aureus；contamination routes;process analysis；barbecue cheese；starter culture
作者：Johler, S.；Zurfluh, K.；Stephan, R.
作者单位：瑞士苏黎世大学
期刊名称：Journal of Dairy Science
期刊影响因子：2.408
出版年份：2016
出版刊次：5
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