Propionibacterium freudenreichii freudenreichii B3523 reduces cecal colonization and internal organ dissemination of multidrug-resistant Salmonella Heidelberg in finishing turkeys

Combination of autochthonous Lactobacillus strains and trans-Cinnamaldehyde in water reduces Salmonella Heidelberg in turkey poults

Reducing the colonization of Salmonella in turkeys is critical to mitigating the risk of its contamination at later stages of production. Given the increased susceptibility of newly hatched poults to Salmonella colonization, it is crucial to implement interventions that target potential transmission routes, including drinking water. As no individual intervention explored to date is known to eliminate Salmonella, the United States Department of Agriculture-Food Safety Inspection Service (USDA-FSIS) recommends employing multiple hurdles to achieve a more meaningful reduction and minimize the potential emergence of resistance. Probiotics and plant-derived antimicrobials (PDAs) have demonstrated efficacy as interventions against Salmonella in poultry. Therefore, this study aimed to investigate the use of turkey-derived Lactobacillus probiotics (LB; a mixture of Lactobacillus salivarius UMNPBX2 and L. ingluviei UMNPBX19 isolated from turkey ileum) and a PDA, trans-cinnamaldehyde (TC), alone and in combination (CO), against S. Heidelberg in turkey drinking water and poults. The presence of 5% nutrient broth or cecal contents as contaminants in water resulted in S. Heidelberg growth. TC eliminated S. Heidelberg, regardless of the contaminants present. In contrast, the cecal contents led to increased survival of Lactobacillus in the CO group. Unlike TC, LB was most effective against S. Heidelberg when the nutrient broth was present, suggesting the role of secondary metabolites in its mechanism of action. In the experiments with poults, individual TC and LB supplementation reduced cecal S. Heidelberg in challenged poults by 1.2- and 1.7-log10 colony-forming units (CFU)/g cecal contents, respectively. Their combination yielded an additive effect, reducing S. Heidelberg by 2.7 log10 CFU/g of cecal contents compared to the control (p ≤ 0.05). However, the impact of TC and LB on the translocation of S. Heidelberg to the liver was more significant than CO. TC and LB are effective preharvest interventions against S. Heidelberg in poultry production. Nonetheless, further investigations are needed to determine the optimum application method and its efficacy in adult turkeys.

Effect of pimenta essential oil against Salmonella Agona and Salmonella Saintpaul in ground turkey meat and nonprocessed turkey breast meat

Salmonella enterica Agona (S. Agona) and Salmonella enterica Saintpaul (S. Saintpaul) are among the emerging drug-resistant Salmonella in turkey production and processing. Rapid solutions to control emerging and uncommon serotypes such as S. Agona and S. Saintpaul are needed. This study tested pimenta essential oil (PEO) as a processing antibacterial against S. Agona and S. Saintpaul in experiments representative of different stages of turkey processing. The compound effectively reduced S. Agona and S. Saintpaul in nutrient broth studies and with mature biofilm assays. PEO was tested against a combination of S. Agona and S. Saintpaul in ground turkey meat and nonprocessed breast meat. In the first experiment with ground turkey, samples were inoculated with a mixture of S. Agona and S. Saintpaul (∼3 log10 CFU/g) and treated with PEO at different concentrations (0% PEO, 0.25% PEO, 0.5% PEO, 1% PEO, 2% PEO, and 2.5% PEO). In the second experiment with turkey breast, samples inoculated with ∼3 log10 CFU/g (SA+SP) were dipped in different concentrations of PEO with chitosan (CN) for 2 min. In both these experiments, samples were stored at 4°C, and Salmonella recovery was carried out at 0, 1, 3, 5, and 7 d. All experiments followed a completely randomized design and were repeated 6 times (n = 6). Statistical analysis was done using the PROC-ANOVA procedure of SAS. In the ground turkey meat, PEO at or above 2% reduced 2 log10 CFU/g of Salmonella by day 1. PEO at 2.5% in ground turkey meat resulted in enrichment-negative samples by 1 min, indicative of the rapid killing effect of the compound at a high concentration of PEO (P ≤ 0.05). A maximum reduction of 1.7 log10 CFU Salmonella/g of turkey breast meat was obtained after 2 min of dip treatment containing CN and 2.5% PEO. Results indicate that PEO could be used as a plant-based processing antibacterial against S. Agona and S. Saintpaul in turkey processing. Upscaling to plant-level studies is necessary before recommending its usage.

Effect of plant-derived antimicrobials, eugenol, carvacrol, and β-resorcylic acid against Salmonella on organic chicken wings and carcasses

Organic poultry constitutes a sizeable segment of the American organic commodities market. However, processors have limited strategies that are safe, effective, and approved for improving the microbiological safety of products. In this study, the efficacy of 3 plant-derived antimicrobials (PDAs), eugenol (EG), carvacrol (CR), and β-resorcylic acid (BR) was evaluated against Salmonella on organic chicken wings and carcasses. Wings inoculated with Salmonella (6 log10 CFU/wing) were treated with or without the treatments (BR [0.5%, 1% w/v], EG [0.5%, 1% v/v], CR [0.5%, 1% v/v], chlorine [CL; 200 ppm v/v], or peracetic acid [PA; 200 ppm v/v]) applied for 2 min at 54°C (scalding study) or 30 min at 4°C (chilling study). Homogenates and treatment water were evaluated for surviving Salmonella. Six wings or carcasses per treatment were analyzed in each study. All treatments, except CL and 0.5% BR in the scalding study, yielded significant reductions of Salmonella on wings compared to the positive control (PC-Salmonella inoculated samples not treated with antimicrobials). To follow, carcasses inoculated with Salmonella (higher inoculum [106 CFU/carcass] or lower inoculum [104 CFU/carcass]) and immersed in antimicrobials (CR 1% [v/v] and industry controls [CL {200 ppm}, or PA [200 ppm]) for 30 min at 4°C were stored until analysis. For the higher inoculum study, 1% CR resulted in a 3.9 log10 CFU/g reduction of Salmonella on the carcass on d 0 compared to PC (P < 0.05); however, CL yielded no reduction. On d 3, CR and PA resulted in 0.9 and 1.2 log10 CFU/g reduction of Salmonella, respectively (P < 0.05). For the lower inoculum study, consistent Salmonella reductions were obtained with CR and PA (1.4-2.1 log10 CFU/g) on d 0 and 7. High reductions of Salmonella in processing water were obtained in all studies. CR effectively controls Salmonella on wings and carcasses and in processing water immediately after application. Follow-up studies on the organoleptic characteristics of PDA-treated chicken carcasses are necessary.

Effect of plant-derived antimicrobials against multidrug-resistant Salmonella Heidelberg in ground Turkey

Salmonella Heidelberg (SH) is a highly invasive human pathogen for which turkeys can serve as reservoir hosts. Colonization of turkeys with SH may result in potential contamination and is a greater challenge to prevent in comminuted products. Antimicrobial efficacy of 3 GRAS-status plant-derived antimicrobials (PDAs), lemongrass essential oil (LG), citral (CIT), and trans-cinnamaldehyde (TC), against SH in ground turkey, a comminuted product implicated in several outbreaks, was evaluated in this study. Ground turkey samples inoculated with ∼3.50 log₁₀ CFU/g of a three-strain SH cocktail were treated with either LG, CIT, or TC at either 0.5, 1, or 2% (vol/wt). Samples were stored at 4°C, and bacterial enumeration was performed on d 0, 1, 3, and 5. Appropriate controls were included alongside all treatments. Fluorescence microscopy was performed to evaluate the direct impact of the PDAs against SH in vitro. Appearance and aroma difference testing of raw patties was also performed for select treatments with trained sensory panelists. Treatment with 2% TC yielded a 2.5 log₁₀ CFU/g reduction by d 1 and complete reduction by d 5 (P < 0.05). By d 3, 2% CIT and 2% LG resulted in SH reduction of at least 1.7 log₁₀ CFU/g (P < 0.05). Addition of 1% TC resulted in reduction of at least 1.8 log₁₀ CFU/g by d 3 (P < 0.05). Participants could distinguish PDA-treated raw patties by aroma. Most participants (7/11) could not distinguish patties treated with 0.5% TC based on appearance. Microscopic images indicate that all PDAs resulted in disruption of the SH membrane. Results of the present study indicate that the three tested PDAs, LG, CIT, and TC are effective against SH in ground turkey, indicating their potential use as interventions to mitigate Salmonella contamination in comminuted turkey products.