Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
J Food Prot. 2009 Nov;72(11):2284-92. doi: 10.4315/0362-028x-72.11.2284.
A biocontrol preparation based on a combination of Enterobacter asburiae JX1 and a cocktail of five lytic bacteriophages was evaluated for control of Salmonella Javiana within the rhizosphere of plants and in pre- and postharvest tomatoes. The biocontrol preparation introduced into the rhizosphere of growing tomato plants reduced the persistence of Salmonella, although no synergistic action was observed between E. asburiae JX1 or the bacteriophage cocktail when used in combination. When the biocontrol preparation was coinoculated with Salmonella onto the blossom of tomato plants, the prevalence of the enteric pathogen both on the surface and in internal tissues of the subsequent tomatoes was significantly reduced compared with controls. Tomatoes derived from plants inoculated with Salmonella alone had a prevalence of 92% surface contamination (22 of 24 tomato batches were positive for Salmonella) and 43% internal contamination (31 of 72 batches positive). This Salmonella prevalence was reduced to 0% (0 of 38 positive) and 2% (1 of 57 positive), respectively, when the biocontrol preparation was applied. Although bacteriophages reduced the prevalence of internalized Salmonella, the main growth suppressing effect was via the antagonistic activity of E. asburiae JX1. No bacteriophages were recovered from tomatoes despite being introduced at 6 log PFU onto the blossom of plants. The biocontrol preparation was not effective for controlling the growth of Salmonella introduced onto postharvest tomatoes that were stored for 7 days at 15 degrees C. The application of E. asburiae JX1 is a promising approach for controlling Salmonella encountered in tomato production, and there was no evidence to suggest that the antagonistic activity could be enhanced by the coinoculation of bacteriophages.
一种基于组合 Enterobacter asburiae JX1 和五种溶菌噬菌体鸡尾酒的生物防治制剂，用于控制植物根际和预收获及收获后番茄中的沙门氏菌 Javiana。将生物防治制剂引入生长中的番茄植物的根际中，降低了沙门氏菌的持久性，尽管当 E. asburiae JX1 或噬菌体鸡尾酒联合使用时，没有观察到协同作用。当生物防治制剂与沙门氏菌一起接种到番茄植物的花上时，与对照相比，肠道病原体在随后的番茄表面和内部组织中的流行率显著降低。仅用沙门氏菌接种的番茄中，表面污染的流行率为 92%（24 批番茄中有 22 批呈沙门氏菌阳性），内部污染的流行率为 43%（72 批中有 31 批呈沙门氏菌阳性）。当应用生物防治制剂时，沙门氏菌的流行率分别降低到 0%（38 批中有 0 批呈阳性）和 2%（57 批中有 1 批呈阳性）。尽管噬菌体降低了内化沙门氏菌的流行率，但主要的生长抑制作用是通过 E. asburiae JX1 的拮抗活性。尽管噬菌体以 6 log PFU 的浓度接种到植物的花上，但在番茄中未回收噬菌体。生物防治制剂对控制在 15 摄氏度下储存 7 天的收获后番茄中引入的沙门氏菌的生长无效。应用 E. asburiae JX1 是控制番茄生产中遇到的沙门氏菌的一种很有前途的方法，并且没有证据表明通过噬菌体的共同接种可以增强拮抗活性。
