The market for ready-to eat vegetables is increasing, but unfortunately so do the numbers of food-borne illness outbreaks related to these products. A previous study has identified bacterial strains suitable for biocontrol of leafy green vegetables to reduce the exposure to pathogens in these products. As a tentative safety evaluation, five selected strains (Rhodococcus cerastii MR5x, Bacillus coagulans LMG P-32205, Bacillus coagulans LMG P-32206, Pseudomonas cedrina LMG P-32207 and Pseudomonas punonensis LMG P-32204) were individually compared for immunomodulating effects in mice and in human monocyte-derived dendritic cells (MoDCs). Mice receiving the two B. coagulans strains consistently resemble the immunological response of the normal control, and no, or low, cell activation and pro-inflammatory cytokine expression was observed in MoDCs exposed to B. coagulans strains. However, different responses were seen in the two models for the Gram-negative P. cedrina and the Gram-positive R. cerastii. Moreover, P. punonensis and B. coagulans increased the microbiota diversity in mice as seen by the Shannon-Wiener index. In conclusion, the two strains of B. coagulans showed an immunological response that indicate that they lack pathogenic abilities, thus encouraging further safety evaluation and showing great potential to be used as biocontrol agents on leafy green vegetables.

即食蔬菜的市场正在增加，但不幸的是，与这些产品相关的食源性疾病暴发的数量也在增加。先前的一项研究已经确定了适用于绿叶蔬菜生物防治的菌株，以减少这些产品中病原体的暴露。作为一项初步的安全性评估，分别比较了五种选定菌株（红球菌MR5x、凝结芽孢杆菌LMG P-32205、凝结芽孢杆菌LMG P-32206、雪松假单胞菌LMG P-32207 和Pseudomonas punonensis LMG P-32204）对小鼠的免疫调节作用在人类单核细胞衍生的树突状细胞 (MoDCs) 中。接受两种凝结芽孢杆菌的小鼠菌株始终类似于正常对照的免疫反应，并且在暴露于凝结芽孢杆菌菌株的 MoDC 中未观察到或观察到低细胞活化和促炎细胞因子表达。然而，在革兰氏阴性P. cedrina和革兰氏阳性R. cerastii的两个模型中看到了不同的反应。此外，如 Shannon-Wiener 指数所示， P. punonensis和B. coagulans增加了小鼠的微生物群多样性。总之，这两种凝结芽孢杆菌菌株显示出免疫反应，表明它们缺乏致病能力，因此鼓励进一步的安全性评估，并显示出用作绿叶蔬菜生物防治剂的巨大潜力。