Table_1_Isolation, Characterization, and Application of Bacteriophage LPSE1 Against Salmonella enterica in Ready to Eat (RTE) Foods.DOC

Salmonella infection is an important foodborne consumer health concern that can be mitigated during food processing. Bacteriophage therapy imparts many advantages over conventional chemical preservatives including pathogen specificity, natural derivation, potency, and providing a high degree of safety. The objective of this study aimed to isolate and characterize a phage that effectively control Salmonella food contamination. Out of 35 isolated phages, LPSE1 demonstrated a broad Salmonella host range, robust lytic ability, extensive pH tolerance, and prolonged thermal stability. The capacity for phage LPSE1 to control Salmonella Enteritidis-ATCC13076 in milk, sausage, and lettuce was established. Incubation of LPSE1 at 28°C in milk reduced recoverable Salmonella by approximately 1.44 log10 CFU/mL and 2.37 log10 CFU/mL at MOI of 1 and 100, respectively, as relative to the phage-excluded control. Upon administration of LPSE1 at an MOI of 1 in sausage, Salmonella count decreased 0.52 log10 at 28°C. At MOI of 100, the count decreased 0.49 log10 at 4°C. Incubation of LPSE1 on lettuce reduced recoverable Salmonella by 2.02 log10, 1.71 log10, and 1.45 log10 CFU/mL at an MOI of 1, 10, and 100, respectively, as relative to the negative control. Taken together, these findings establish LPSE1 as an effective weapon against human pathogenic Salmonella in various ready to eat foods.

沙门氏菌（Salmonella）感染是一类重要的食源性消费者健康隐患，可通过食品加工环节实现有效防控。噬菌体疗法（Bacteriophage therapy）相较于传统化学防腐剂具备诸多优势，包括病原体特异性、天然来源、高效性及极高的安全性。本研究旨在分离并表征一株可有效防控沙门氏菌食品污染的噬菌体。在35株分离获得的噬菌体中，LPSE1展现出宽泛的沙门氏菌宿主谱、强劲的裂解活性、广泛的pH耐受性以及优异的热稳定性。本研究证实了噬菌体LPSE1对牛奶、香肠及生菜中肠炎沙门氏菌（Salmonella Enteritidis）ATCC13076的防控效能。与不含噬菌体的对照组相比，在28℃下于牛奶中孵育LPSE1时，当感染复数（multiplicity of infection, MOI）为1和100时，可回收沙门氏菌数量分别降低约1.44 log₁₀ CFU/mL和2.37 log₁₀ CFU/mL。在香肠中以感染复数1施用LPSE1时，28℃下沙门氏菌数量降低0.52 log₁₀；当感染复数为100时，4℃下沙门氏菌数量降低0.49 log₁₀。与阴性对照组相比，在生菜上施用LPSE1时，当感染复数分别为1、10和100时，可回收沙门氏菌数量分别降低2.02 log₁₀、1.71 log₁₀和1.45 log₁₀ CFU/mL。综上，本研究结果证实LPSE1可作为防控多种即食食品中人源致病沙门氏菌的有效手段。