Applied Microbiology, Lund Institute of Technology, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.
Food Microbiol. 2011 May;28(3):617-20. doi: 10.1016/j.fm.2010.11.013. Epub 2010 Nov 24.
Staphylococcal enterotoxin D (SED) is one of the most frequently recovered enterotoxins in staphylococcal food poisoning (SFP) outbreaks. The expression and production of SED were investigated in three ham products, i.e. boiled ham, smoked ham and dry-cured Serrano ham incubated at room temperature for seven days. Staphylococcus aureus was also, as a reference, grown in cultivation broth during optimal growth conditions for seven days. In boiled and smoked ham, continuous sed expression was observed throughout the incubation period with a second increase in sed expression found after five days of incubation. In smoked ham, nine times less SED per colony-forming unit of S. aureus was detected than in boiled ham. In boiled ham, the SED levels unpredictably decreased after three days of incubation. In the Serrano ham, SED was detected after five days of incubation although S. aureus growth was poor and sed expression was too low to determine. After five days of incubation, all three products contained enough SED to cause SFP. These results show that the specific production levels of SED vary in the different ham products, and that toxin production was in part uncoupled from bacterial growth.
葡萄球菌肠毒素 D（SED）是葡萄球菌食物中毒（SFP）爆发中最常被回收的肠毒素之一。研究了 3 种火腿制品（即煮火腿、熏火腿和干腌塞拉诺火腿）在室温下孵育 7 天过程中 SED 的表达和产生情况。金黄色葡萄球菌也在最佳生长条件下培养肉汤中培养 7 天作为参考。在煮火腿和熏火腿中，SED 表达连续观察到整个孵育期，孵育 5 天后发现 SED 表达第二次增加。在熏火腿中，每单位金黄色葡萄球菌形成的菌落中检测到的 SED 比煮火腿少 9 倍。在煮火腿中，SED 水平在孵育 3 天后不可预测地下降。在塞拉诺火腿中，孵育 5 天后检测到 SED，尽管金黄色葡萄球菌生长不良，SED 表达过低无法确定。孵育 5 天后，所有 3 种产品都含有足够的 SED 引起 SFP。这些结果表明，SED 的特定产生水平在不同的火腿产品中有所不同，并且毒素产生部分与细菌生长解偶联。
