Yeast Fermentate-Mediated Reduction of Salmonella Reading and Typhimurium in an in vitro Turkey Cecal Culture Model

Abstract

Salmonella Reading is an ongoing public health issue in the turkey industry, leading to significant morbidity in humans in the United States. Pre-harvest intervention strategies that contribute to the reduction of foodborne pathogens in food animals, such as the yeast fermentation metabolites of Original XPCTM (XPC), may become the key to multi-hurdle farm to fork strategies. Therefore, we developed an anaerobic in vitro turkey cecal model to assess the effects of XPC on the ceca of commercial finisher tom turkeys fed diets void of XPC and antibiotics. Using the in vitro turkey cecal culture method, ceca were tested with and without XPC for their anti-Salmonella Reading and the previously defined anti-Typhimurium (ST97) effects. Ultimately, the anti-Salmonella effects were independent of serovar (P > 0.05). At 0 h post inoculation (hpi), Salmonella levels were equivalent between treatments at 7.3 Log10 CFU/mL, and at 24 hpi, counts in XPC were reduced by 5 Log10 CFU/mL, which was 2.1 Log10 lower than the control (P < 0.05). No differences in serovar prevalence existed (P > 0.05), with a 92% reduction in Salmonella positive XPC-treated ceca cultures by 48 hpi (P < 0.05). To evaluate changes to the microbiota independent of the immune response, the 16S rDNA was sequenced using the Illumina MiSeq platform. Data indicated a profound effect of time and treatment for the reduction of Salmonella irrespective of serovar. XPC sustained diversity metrics compared to the control, demonstrating a reduction in diversity over time (Q < 0.05).

Dietary Inclusion of a Saccharomyces cerevisiae-Derived Postbiotic Is Associated with Lower Salmonella enterica Burden in Broiler Chickens on a Commercial Farm in Honduras

“…Resistance to colonization by Salmonella may be partially attributed to short-chain volatile fatty acid (VFA) and other metabolite products from members of the microbiome, as well as maintenance of gut barrier function and immunity [60]. SCFPs have been shown to increased VFA concentrations for acetate and butyrate and promote favorable shifts in abundance of beneficial taxa and inhibition of Salmonella propagation during challenge [40][41][42]61]. In vivo research has identified immunomodulatory benefits of feeding SCFP to broilers, including those challenged with Eimeria tenella, though no Salmonella-specific mechanisms have been investigated to date [36,37].…”

Yeast-Derived Products: The Role of Hydrolyzed Yeast and Yeast Culture in Poultry Nutrition—A Review

“…The stability of the microbiota is directly related to age [ 131 ], and the sooner the microbiota reaches a stable diversity, the sooner the animals are more protected from pathogen invasion [ 132 ] while maximizing the metabolic fermentation and nutrient absorption [ 133 ]. The studies in the literature report a significant effect of YC administration on microbial diversity, indicating that YC might increase diversity and allow the microbiota to stabilize at an earlier age, compared to animals receiving the basal diet only [ 94 , 134 ]. Experiments conducted in vitro, where YC was incubated with the feed and the ceca content of broiler chickens [ 94 , 135 ] or turkeys [ 94 ], resulted in increased alpha and beta diversity, which stabilized over time.…”

“…The studies in the literature report a significant effect of YC administration on microbial diversity, indicating that YC might increase diversity and allow the microbiota to stabilize at an earlier age, compared to animals receiving the basal diet only [ 94 , 134 ]. Experiments conducted in vitro, where YC was incubated with the feed and the ceca content of broiler chickens [ 94 , 135 ] or turkeys [ 94 ], resulted in increased alpha and beta diversity, which stabilized over time. Changes in the gut microbial diversity due to YC administration in the diet were also confirmed by in vivo studies on aged breeder layers [ 83 ] and broilers [ 91 ].…”

“…Nevertheless, other authors observed no significant effect of YC on Lactobacilli , either with culture-dependent [ 85 , 105 ] or culture-independent [ 135 ] methods. Finally, other beneficial bacteria that have been found to be positively affected by YC administration include Bifidobacterium [ 93 ], Ruminococcaceae [ 93 , 94 ], and Faecalibacterium [ 91 ].…”

“…Several authors have focused on the ability of YC to control pathogens. Numerous studies prove the ability of YC to reduce the Salmonella prevalence in the ceca content of broilers [ 95 , 96 ], layer pullets [ 97 ], and turkeys [ 94 ], as well as Salmonella survival [ 96 , 135 ] and shedding in the faeces [ 108 ]. Interestingly, it has been pointed out in in vitro studies that YC is effective at controlling Salmonella only when gut microbiota are present [ 96 , 135 ], while, when YC was incubated alone with the pathogen, it showed no effect.…”