植物乳杆菌ZS2058联合丁香酚协同预防小鼠沙门氏菌感染

[Aim] Previous studies have reported the preventive effects of Lactobacillus plantarum ZS2058 (ZS2058) and eugenol against Salmonella in murine models. This work aims to study the preventive effect of ZS2058combined with eugenol against Salmonella infection in mice and the involved mechanisms. [Methods] Bactericidal activity was evaluated by micro-broth dilution assays. HT-29 cells model and PCR were used to investigate the effects of ZS2058 and eugenol on the invasiveness and virulence gene expression of Salmonella. The synergistic effect was assessed by coefficient drug interaction (CDI). C57BL/6 mice (female, 8 wk old) were pretreated with PBS (group M), ZS2058 (group Z), or eugenol (group E), or ZS2058 and eugenol (group ZE) for 10 days prior to infection with Salmonella, the mortality rate was recorded daily for 20 d. The intestinal microbiota of cecum contents was characterized by 16S rDNA Gene Sequencing. The cytokines in liver were detected by ELISA. [Results] ZS2058 combined with eugenol (CLPZE) treatment (SRZE, 80%) increased the survival rate (SR) of ST-infected mice (SRM, 60%) to two-fold compared with that of treated by ZS2058 alone (SRZ, 70%), and six-fold compared with the effect of eugenol alone (SRE, 63.3%). CLPZE had a synergistic effect on inhibiting ST growth, reducing its invasiveness and downregulating virulence gene expression in vitro. CLPZE helped the host form a healthier gut ecosystem,and elicited a stronger and earlier immune response against systemic infection. [Conclusions] Our studies provide substantial evidence strongly suggesting that CLPZE has a synergistic effect in preventing Salmonella infection in C57BL/6 mice.