Evaluation of the Antimicrobial and Anti-inflammatory Properties of Bacillus-DFM (Norum™) in Broiler Chickens Infected With Salmonella Enteritidis

Abstract

Restrictions of in-feed antibiotics use in poultry has pushed research toward finding appropriate alternatives such as Direct-Fed Microbials (DFM). In this study, previously tested Bacillus isolates ( B . subtilis and B . amyloliquefaciens ) were used to evaluate their therapeutic and prophylactic effects against Salmonella enterica serovar Enteritidis ( S . Enteritidis) in broiler chickens. For this purpose, initial antibacterial activity of Bacillus -DFM (10 4 spores/g or 10 6 spores/g) against S . Enteritidis colonization in crop, proventriculus and intestine was investigated using an in vitro digestive model. Furthermore, to evaluate therapeutic and prophylactic effects of Bacillus -DFM (10 4 spores/g) against S . Enteritidis colonization, altogether 60 ( n = 30/group) and 30 ( n = 15/group) 1-day-old broiler chickens were randomly allocated to either DFM or control group (without Bacillus -DFM), respectively. Chickens were orally gavaged with 10 4 cfu of S . Enteritidis per chicken at 1-day old, and cecal tonsils (CT) and crop were collected 3 and 10 days later during the therapeutic study, whereas they were orally gavaged with 10 7 cfu of S . Enteritidis per chicken at 6-day-old, and CT and crop were collected 24 h later from two independent trials during the prophylactic study. Serum superoxide dismutase (SOD), FITC-d and intestinal IgA levels were reported for both chicken studies, in addition cecal microbiota analysis was performed during the therapeutic study. DFM significantly reduced S . Enteritidis concentration in the intestine compartment, and in both proventriculus and intestine compartments as compared to the control when used at 10 4 spores/g and 10 6 spores/g, respectively ( p < 0.05). DFM significantly reduced FITC-d and IgA as well as SOD and IgA levels ( p < 0.05) compared to the control in therapeutic and prophylactic studies, respectively. Interestingly, in the therapeutic study, there were significant differences in bacterial community structure and predicted metabolic pathways between DFM and control. Likewise, phylum Actinobacteria and the genera Bifidobacterium, Roseburia, Proteus , and cc_115 were decreased, while the genus Streptococcus was enriched significantly in the DFM group as compared to the control (MetagenomeSeq, p < 0.05). Thus, the overall results suggest that the ...

Dietary Inulin Supplementation Modulates Short-Chain Fatty Acid Levels and Cecum Microbiota Composition and Function in Chickens Infected With Salmonella

“…In accordance with previous studies, the current study found that inulin increased the abundances of Streptococcus and Lactobacillus, which were shown to be positively related to butyrate production (Yan et al, 2017). Streptococcus, Lactobacillales, and Firmicutes exhibited a positive relationship with acetate production in the present study, playing an important role in reducing the colonization and incidence of SE through reducing the pH and competitive exclusion (Adhikari et al, 2019).…”

“…CON (n = 3): basal diet without inulin supplementation; SE (n = 3): Salmonella-infected chicken fed with basal diet; 0.5% InSE (n = 3): Salmonella-infected chicken fed with 0.5% inulin; 1% InSE (n = 3): Salmonella-infected chicken fed with 1% inulin. a vital role in reducing the colonization and incidence of SE (Adhikari et al, 2019). In this study, inulin also increased the abundance of Streptococcus.…”

Assessment of Fermented Soybean Meal on Salmonella typhimurium Infection in Neonatal Turkey Poults

“…Even so, this outcome is not new in our laboratory’s experience translating in vitro data to in vivo efficacy. We have observed similar results with other probiotic bacteria against Salmonella enteritidis [ 25 ], or biodegradation of aflatoxin B1 [ 26 ], as well as other nutraceuticals showing significant and encouraging reductions against Histomonas meleagridis in vitro, but none of which translated to effectivity in vivo [ 27 , 28 ]. Hence, in vitro biological effects do not always draw a parallel result when tested in live animals.…”

Dietary Supplementation With Bacillus subtilis Direct-Fed Microbials Alters Chicken Intestinal Metabolite Levels

“…DFMs are viable, naturally occurring microbial cultures, including bacteria belonging to the genera Lactobacillus, Enterococcus, Streptococcus, Bifidobacterium, and Propionibacterium, which when fed to the host animal, generate a beneficial health response through their ability to modulate the diversity and composition of the gut microbiota. Various species of Bacillus also have been tested as DFMs on the basis of their ability to inhibit pathogens by producing antimicrobials (13)(14)(15). Bacillus has the added advantage as a DFM of producing spores that are resistant to low pH, bile salts, and other harsh conditions of the gastric environment (16)(17)(18)(19).…”