Effect of Feeding Bacillus subtilis Spores to Broilers Challenged with Salmonella enterica serovar Heidelberg Brazilian Strain UFPR1 on Performance, Immune Response, and Gut Health

Abstract

Salmonellosis is a poultry industry and public health concern worldwide. Recently, Salmonella enterica serovar Heidelberg (SH) has been reported in broilers in Brazil. The effect of feeding a blend of three strains of Bacillus subtilis (PRO) was studied in broilers orally challenged (107 CFU/chick) or not with a SH isolated in south of Brazil (UFPR1 strain). Twelve male Cobb 500 broilers per pen were randomly assigned to six treatments in a 3 × 2 factorial experiment where PRO was added at 0, 250, or 500 g/ton of broiler feed and fed to either SH-challenged (SH Control, SH + PRO 250, and SH + PRO 500) or non-challenged birds (Control, PRO 250, and PRO 500). Broiler performance, histologic alterations in intestinal morphology, Salmonella quantification and immune cells counts in liver (macrophages, T CD4+ and T CD8+) were analyzed. Changes in the intestinal microbiota of broilers were also studied by metagenomics for Control, SH Control, SH + PRO 250, and SH + PRO 500 only. Feeding PRO at 250 or 500 g/ton reduced SH counts and incidence in liver and cecum at 21 days of age. It was observed that PRO groups increased the macrophage mobilization to the liver in SH-challenged birds (P < 0.05) but reduced these cells in the liver of non-challenged birds, showing an interesting immune cell dynamics effect. PRO at 250 g/ton did not affect gut histology, but improved animal performance (P < 0.05) while PRO at 500/ton did not affect animal performance but increased histologic alteration related to activation of the defense response in the ileum in SH challenged birds compared to control birds (P < 0.05). SH + PRO 500 group presented a more diverse cecal microbiota (Shannon–Wiener index; P < 0.05) compared to Control and SH Control groups; while SH + PRO 250 had greater ileal richness (JackkNife index) compared to Control (P < 0.05). PRO was effective in reducing Salmonella colonization in liver and cecum when fed at 250 or 500 g/ton to broilers inoculated with SH strain UFPR1. PRO promotes positive alterations in performance (at 250 g/ton), immune modulatory effect in the gastrointestinal tract, SH reduction, and intestinal microbiota modulation.

Titration of supplemental Bacillus subtilis subsp. subtilis American Type Culture Collection PTA-125135 to broiler chickens fed diets of 2 different metabolizable energy concentrations

“…Applied doses (per g feed) of other Bacillus strains that have been reported as efficacious in the literature span more than a 2-log range from 1.0 × 10 5 CFU for strain LS 1-2 ( Sen et al., 2012 ) to 4.0 × 10 7 CFU ( Bai et al., 2017 ). Other test doses have included 1.0 × 10 6 CFU per g for either a multistrain Bacillus probiotic ( Hayashi et al., 2018 ) or for strain DSM 32315 ( Sokale et al., 2019 ) or 10 7 CFU per g or greater for strains CGMCC 1.1086 ( Li et al., 2016 ), American Type Culture Collection PTA-6737 ( Abudobos et al., 2017 ), and CSL-2 ( Oh et al., 2017 ). Therefore, although the present study effectively identified dose-responsive effects within the titrated range up to 3.2 × 10 5 CFU per g, it is possible that PTA-125135 doses well in excess of the titrated range could be tolerated by poults and could be favorable for improving feed efficiency.…”

Effect of Antibiotic, Phytobiotic and Probiotic Supplementation on Growth, Blood Indices and Intestine Health in Broiler Chicks Challenged with Clostridium perfringens

“…Supplementing diets with probiotics could help to prevent some of the harmful modifications caused by Salmonella enterica in the hepatocellular parenchyma [83]. NE can potentially lead to the degeneration and vacuolation of hepatocytes [84].…”

Bacillus subtilis spores as adjuvants against avian influenza H9N2 induce antigen-specific antibody and T cell responses in White Leghorn chickens

“…In previous studies, B. subtilis spores showed potential for use as an adjuvant in mice. B. subtilis spores not only enhance innate immunity that protects against respiratory infections [12][13][14] but also induce an increase in antigen-specific antibody and T cell responses when co-administered with a soluble antigen [15][16][17]. B. subtilis spore-induced cross-presentation in response to a co-administered antigen suggests that the spore instructs diverse antigen-specific adaptive immune responses [15,18].…”