本研究以产生金黄色葡萄球菌新型肠毒素P的食品源分离株SA-106为研究对象，采用平板计数和酶联免疫方法研究菌株在LB培养基、脱脂乳和无菌熟猪肉中的生长及肠毒素SEP的动态分泌；同时探索食品添加剂茶多酚和Nisin对菌株SEP 蛋白分泌影响。结果表明菌株SA-106在LB液体培养基和脱脂乳中生长时，细菌均能在12 h左右进入生长稳定期，在细菌生长过程中，肠毒素SEP蛋白分泌呈持续增加趋势，在检测的第120 h分别达到10.28 μg/mL和6.59 μg/mL；菌株在猪肉中生长时，24 h左右进入稳定期，在检测的第48 h时，SEP分泌量可达到9.12 μg/g。通过比较发现，菌株SA-106在熟猪肉和LB培养基中生长，SEP蛋白分泌量较高，在脱脂乳中SEP蛋白分泌量稍低，说明不同培养基质对肠毒素蛋白P的分泌强度有影响；另外，茶多酚和Nisin的添加对细菌的生长和肠毒素SEP的产生有一定抑制效果。研究结果对葡萄球菌肠毒素P的产生和控制提供一定参考。

In this study, the food-source Staphylococcus aureus SA-106 strain, which produces new staphylococcal enterotoxin P, was used as a research object. The growth of strain in LB medium, skim milk and sterile cooked pork was studied by plate counting, and the secretion of staphylococcal enterotoxin P was determined by enzyme-linked immunosorbent assay. At the same time, the effects of food additives (tea polyphenols and Nisin) on the secretion of SEP protein were also explored. The results showed that when SA-106 was grown in LB medium and skim milk, the bacteria could enter the growth stationary period at about 12 h; and the secretion of enterotoxin SEP protein continued to increase during the growth, reaching 10.28 μg/mL and 6.59 μg/mL at 120 h, respectively. While when grown in pork, the strain entered the growth stationary period at about 24 h, and the SEP secretion was 9.12 μg/g at 48 h. By comparison, the secretion of SEP protein of strain S-106 was higher in cooked pork and LB medium, and the secretion of SEP protein in skim milk was slightly lower, indicating that different culture medium had an effect on the secretion of enterotoxin protein P. Further, the addition of tea polyphenols and Nisin has a certain inhibitory effect on the growth of bacteria and the production of enterotoxin SEP. This study has a certain reference value for the production and control of staphylococcal enterotoxin P.

国家重点研发计划项目(2018YFD0500500)；四川省科技计划项目（2019YJ0261)；西南民族大学研究生创新项目（CX2019SZ148）