Bacillus toyonensis BCT-7112T transient supplementation improves vaccine efficacy in ewes vaccinated against Clostridium perfringens epsilon toxin.

AIM: The aim of the present study was to examine the vaccine immune response in ewes supplemented with Bacillus toyonensis BCT-7112T during a period of 5-day supplementation before vaccination against a recombinant Clostridium perfringens epsilon toxin (rETX). METHODS AND RESULTS: Ewes were vaccinated with 200 µg of rETX adjuvanted with 10% aluminium hydroxide. The treat group was orally supplemented with B. toyonensis BCT-7112T (3 × 108 viable spores) for 5 days prior to the first and second vaccination. Ewes supplemented with B. toyonensis BCT-7112T showed higher neutralizing antibody titres than the non-supplemented ewes (P < 0·05), with an increase in serum levels for total IgG anti-rETX by 3·2-fold (P < 0·0001), and for both IgG isotypes IgG1 and IgG2 by 2·1-fold and 2·3-fold (P < 0·01), respectively, compared with the control group. The peripheral blood mononuclear cells of ewes in the supplemented group had a higher (P < 0·05) cytokine mRNA transcription levels for IL-2 (6·4-fold increase), IFN-γ (2·9-fold increase) and transcription factor Bcl6 (2·3-fold increase) compared with the control group. CONCLUSION: We conclude that a 5 days of supplementation with B. toyonensis BCT-7112T prior vaccination is sufficient to significantly improve the humoral immune response of ewes against C. perfringens recombinant ETX vaccine. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings open a new perspective in the utilization of B. toyonensis BCT-7112T as an immunomodulator since a 5 days period of probiotic supplementation is sufficient to improve the vaccine immune response.

The effect of litter materials on broiler performance: a systematic review and meta-analysis.

1. Divergence in outcomes from studies on the effects of litter materials on body weight, feed intake, feed conversion and mortality in broilers has led to a need for a meta-analysis to quantify their effects.2. A systematic search of published quantitative research relating to wood shavings and alternative bedding litters was conducted using databases.3. Means, standard deviations and sample sizes were extracted from each study. The response variables were analysed using the standardised mean difference (SMD, control treatment minus alternative litters).4. The literature demonstrated that alternative materials have no impact on feed intake in broilers, compared to wood shavings (SMD = 0.064, 95% CI = -0.101-0.229, P = 0.44).5. There was a positive overall effect of wood shavings on body weight (SMD = 0.253, 95% CI = 0.073-0.433, P = 0.006), feed conversion (SMD = -0.169, 95% CI = -0.327 - -0.012, P = 0.03) and mortality (SMD = -1.069, 95% CI = -1.983 - -0.155, P = 0.02) of broilers, compared to other litter types.6. Subgroup meta-analysis revealed that straw, when used as an alternative litter material to wood shavings, may be responsible for lower body weight (SMD = 0.654, 95% CI = 0.162-1.146, P = 0.009), worse feed conversion (SMD = -0.487, 95% CI = -0.828 - -0.145, P = 0.005) and higher mortality rates of broilers (SMD = -3.25, 95% CI = -5.681 - -0.819, P = 0.009). Rice husks impaired body weight compared to wood shavings (SMD = 0.535, 95% CI = 0.065-1.004, P = 0.02).7. It was concluded that different litter types do not affect the broilers' feed intake. Conversely, broilers kept on straw showed lower body weights, worse feed conversion and higher mortality rates, in comparison to wood shavings. Rice husks decreased body weight compared to wood shavings.

Modulation of IL-12 and IFNγ by probiotic supplementation promotes protection against Toxocara canis infection in mice.

In this study, supplementation with the probiotic Saccharomyces boulardii promoted a reduction in intensity of infection by Toxocara canis and modulates cytokines mRNA expression in experimentally infected mice. IL-12 gene transcription had 40-fold increase in S. boulardii supplemented uninfected mice and sevenfold increase in supplemented infected mice comparing with not supplemented group. Regarding IFNγ, similar results were observed, since probiotic supplementation induced approximately 43-fold increase, but only in uninfected mice (P < 0·05). T. canis infection upregulated IL-10 expression while S. boulardii downregulated it and no change was observed for IL-4. Thus, based in these findings; we suggest that one possible mechanism responsible for S. boulardii protection effect against T. canis infection is by the modulation of cytokines expression, especially IL-12.