Synbiotic supplementation to decrease Salmonella colonization in the intestine and carcass contamination in broiler birds.

In vitro and in vivo experiments were conducted to study the effects of synbiotic supplementation on Salmonella enterica ser. Enteritidis (SE) proliferation, cecal content load, and broiler carcass contamination. Lactobacillus reuteri, Enterococcus faecium, Bifidobacterium animalis, and Pediococcus acidilactici culture supernatants decreased (P < 0.05) the in vitro proliferation of SE at 1:1 supernatant: pathogen dilution. A total of 240 Cobb-500 broiler chicks were randomly allotted to three treatment groups (8 replicates/group with 10 birds/replicate): control (basal diet), antibiotic (Virginiamycin at 20 mg/kg feed), synbiotic (PoultryStar® ME at 0.5 g/kg feed containing L. reuteri, E. faecium, B. animalis, P. acidilactici and a Fructooligosaccharide) from day of hatch. At 21 d of age, all birds in experimental groups were orally inoculated with 250 µl of 1 X 109 CFU SE. Antibiotic supplementation increased (P < 0.05) body weight and feed consumption, compared to the control group. Birds in the synbiotic supplementation had intermediate body weight and feed consumption that were not significantly different from both the control and antibiotic group at 42 d of age in SE infected birds. No significant effects were observed in feed efficiency at 42 d of age among the groups. Antibiotic and synbiotic supplementation decreased (P < 0.05) SE load in cecal contents by 0.90 and 0.85 log units/ g and carcass SE load by 1.4 and 1.5 log units/mL of rinsate compared to the control group at 42 d of age (21 dpi). The relative abundance of IL-10, IL-1, TLR-4, and IFNγ mRNA was decreased (P < 0.05) in the antibiotic and synbiotic supplementation groups compared to the control birds at 42 d of age (21 dpi). It can be concluded that synbiotic supplementation decreased SE proliferation in vitro and decreased SE load in the cecal contents and broiler carcass.

Effect of dietary supplementation of nitrocompounds on Salmonella colonization and ileal immune gene expression in laying hens challenged with Salmonella Enteritidis.

Foodborne disease caused by Salmonella Enteritidis (SE) is one of the important public health and economic concerns. A study was conducted to determine the effect of supplementation with 2-nitroethanol (NE) and 2-nitropropanol (NP) on Salmonella recovery of internal organs as well as on the immune gene expression in the ileum of laying hens. Thirty-six White Leghorns were orally gavaged with nalidixic acid resistant Salmonella Enteritidis (SENR). Hens were housed individually in wire-laying cages and randomly assigned to six dietary treatments: T1 = SENR unchallenged (negative control), T2 = SENR challenged (positive control), T3 = SENR challenged + 100 ppm NE, T4 = SENR challenged + 200 ppm NE, T5 = SENR challenged + 100 ppm NP, and T6 = SENR challenged + 200 ppm NP. Hens were sampled at 7 days post inoculation (dpi). Ceca, liver with gall bladder (L/GB), and ovary samples were collected for bacteriology, and ileum samples were collected for analysis of immune gene expression. T3 and T6 significantly reduced (P < 0.05) cecal SENR count, whereas T4 and T5 were not different from T2, the SENR challenged control. There was no significant difference in SENR reduction in the L/GB or ovary after supplementation of either nitrocompounds. Pro- and anti-inflammatory cytokines such as interferon (IFN)-γ, interleukin (IL)-1B, IL-6, toll-like receptors (TLR)-4, and IL-10 all were significantly upregulated (P < 0.05) after SENR challenge. Supplementation at both levels of NE and NP showed a significant immune gene expression response in the ileum with reduction of IFN-γ, IL-6, TLR-4, and IL-10 mRNA expression. Overall, nitrocompounds such as NE and NP can be used in the intervention strategy to reduce Salmonella infection in hens.

Evaluation of encapsulated sodium butyrate on growth performance, energy digestibility, gut development, and Salmonella colonization in broilers.

Two experiments were conducted to determine the effect of an encapsulated sodium butyrate (Na-B) with targeted releasing times on broiler performance, energy digestibility, intestinal morphology, and ceca Salmonella colonization. In experiment 1, 3 different Na-B products (CMA, CMP, and CMS) were evaluated following a challenge with a nalidixic acid-resistant Salmonella typhimurium (STNAR). Cobb-Cobb male birds were placed 8 per pen into 6 replicates for each treatment. Treatments included 6 Na-B treatments (500 and 1,000 ppm of each product) plus 2 control (non-challenged and challenged). Birds were orally gavaged with 0.1 mL of 107 cfu/mL STNAR on d 4. Ceca and ileal samples were collected on d 11. In experiment 2, CMA and CMP products were evaluated for a full grow-out period without an external challenge. Cobb-Cobb male birds were distributed among 45 floor pens with 24 birds per pen. Treatments included 4 product treatments (500 and 1,000 ppm of each product) plus one control. Feed intake and pen weight were obtained on d 14, 28, and 42. Experiment 1 showed that CMP at 1,000 ppm had the highest value for BW and BWG on d 4 (P = 0.07). Adding CMA and CMP at 500 ppm increased ileal digestibility energy (IDE) compared to the challenged control (P ≤ 0.05). The Salmonella recovery data indicated that the challenge had a significant but mild impact, since it did not affect the performance variables but did result in a significant increase in log10 cfu/g cecal material between the non-challenged and challenged control (1.42 vs 3.72). Experiment 2 showed that both products improved the villus height in the duodenum on d 21 (P = 0.08) and IDE on d 42, relative to the control (P ≤ 0.05). This study demonstrates that Na-B has the potential to improve growth in broilers at an early age. The beneficial effects on intestinal morphology and IDE are affected not only by dosage level, but also by the product's releasing time.

Effect of dietary bacteriophage supplementation on internal organs, fecal excretion, and ileal immune response in laying hens challenged by Salmonella Enteritidis.

With the current researches on replacing antibiotics with different dietary interventions, bacteriophages (BP) are potential antimicrobial intervention because of their ability to affect specific bacteria. A study was conducted to evaluate the role of BP against Salmonella enterica serovar Enteritidis (SE) on SE internal organs colonization and ileum immune response in laying hens. Hens were challenged both orally and intracloacally with 108 cfu/mL cells of nalidixic acid resistant Salmonella Enteritidis (SENAR). Thirty-two Single Comb White Leghorns were randomly allocated to 4 dietary treatments: 1) unchallenged control (negative control; T1), 2) SENAR challenged control (positive control; T2), 3) SENAR challenged + 0.1% BP (T3), and 4) SENAR challenged + 0.2% BP (T4). The number of SENAR in the ceca was significantly reduced by 0.2% BP supplementation (P < 0.05) at 7 d post infection (dpi). The respective number of SENAR was reduced from 2.9 log cfu/gm in T2 and T3 to 2.0 log cfu/gm in T4. There was no significant effect of T3 on reduction of numbers of cecal SENAR. A significant reduction of SENAR was observed in the liver with gall bladder (LGB) from 0.75 in T2 to 0.18 log cfu/gm in T4. In the spleen, T4 significantly reduced (P < 0.05) SENAR to 0.56 log cfu/gm compared to T2 and T3 (0.94 log cfu/gm). There was no significant effect of T3 in reduction of prevalence of spleen SENAR. By supplementing 0.2% BP (T4), the SENAR in the ovary was reduced to 0 log cfu/gm. There was a significant reduction (P < 0.05) in fecal SENAR at 6 dpi by T4 (0.71 log cfu/gm) compared to the positive control (1.57 log cfu/gm). The expression of interferon (IFN)-Γ, interleukin (IL)-6, and IL-10 was significantly increased in the ileum by SENAR challenge compared to the negative control. This study suggests that apart from commonly used prebiotics or probiotics, BP are pathogen-specific and can be used as one of the dietary strategies to reduce SE colonization and induce immune modulation in laying hens.