Preventive antimicrobial action and tissue architecture ameliorations of Bacillus subtilis in challenged broilers

Abstract

Background and Aim: Probiotics improve intestinal balance through bacterial antagonism and competitive exclusion. This study aimed to investigate the in vitro antimicrobial activity, as well as the in vivo preventive, immunological, productive, and histopathological modifications produced by probiotic Bacillus subtilis. Materials and Methods: The in vitro antimicrobial activities of B. subtilis (5×106 CFU/g; 0.5, 1.0*, 1.5, and 2.0 g/L) were tested against Escherichia coli O157: H7, Salmonella Typhimurium, Candida albicans, and Trichophyton mentagrophytes after exposure times of 0.25, 0.5, 1, and 2 h using minimal inhibitory concentration procedures. A total of 320 1-day-old female Ross broiler chickens were divided into five groups. Four out of the five groups were supplemented with 0.5, 1.0*, 1.5, and 2.0 g/L probiotic B. subtilis from the age of 1 day old. Supplemented 14-day-old broiler chickens were challenged with only E. coli O157: H7 (4.5×1012 CFU/mL) and S. Typhimurium (1.2×107 CFU/mL). A total of 2461 samples (256 microbial-probiotic mixtures, 315 sera, 315 duodenal swabs, and 1575 organs) were collected. Results: The in vitro results revealed highly significant (p<0.001) killing rates at all-time points in 2.0 g/L B. subtilis: 99.9%, 90.0%, 95.6%, and 98.8% against E. coli, S. Typhimurium, C. albicans, and T. mentagrophytes, respectively. Broilers supplemented with 1.5 and 2.0 g/L B. subtilis revealed highly significant increases (p<0.01) in body weights, weight gains, carcass weights, edible organs' weights, immune organs' weights, biochemical profile, and immunoglobulin concentrations, as well as highly significant declines (p<0.01) in total bacterial, Enterobacteriaceae, and Salmonella counts. Histopathological photomicrographs revealed pronounced improvements and near-normal pictures of the livers and hearts of broilers with lymphoid hyperplasia in the bursa of Fabricius, thymus, and spleen after supplementation with 2.0 g/L B. subtilis. Conclusion: The studies revealed that 1.5-2.0 g of probiotic B. subtilis at a concentration of 5×106 CFU/g/L water was able to improve performance, enhance immunity, and tissue architecture, and produce direct antimicrobial actions.

Effects of Bacillus amyloliquefaciens LFB112 on Growth Performance, Carcass Traits, Immune, and Serum Biochemical Response in Broiler Chickens

“…Luan et al [ 57 ] found that dietary spraying with B. amyloliquefaciens enlarged the spleen and bursa in the broilers. The results by Soliman et al showed that supplementation of 1.5 and 2.0 g B. subtilis (5 × 10 6 CFU/g in each liter of drinking water) led to increased carcass, edible organ, and immune organ weights [ 58 ]. These reports were consistent with our finding that the addition of Bacillus amyloliquefaciens LFB112 (C + M) could significantly improve the thymus and spleen index of broilers.…”

Nile Tilapia Bones as Eco-Friendly Alternative in Water Treatment and Enhancing Performance and Immunity in Broiler Chickens

“…Escherichia coli O157: H7 suspension (1.8 × 10 3 CFU/ml) was purchased from Animal Health Research Institute- Ismailia- Egypt. The bacterial suspension was propagated as recommended by Soliman et al . (2021b ) into Falcon tubes set with 9 ml of MacConkey broth (Thermo Scientific™ Oxoid™ MacConkey Broth, CM0505, 500 g) at 44°C.…”

The Influence of Lactococcus and Bacillus species Probiotics on Performance, Energy Utilization, Intestinal Ecosystem of Broiler Chickens

“…Meanwhile, L. lactis bacteria are well characterized as food-grade lactic acid bacteria which can produce several metabolic substances, including acetic acid and lactic acid that shift the intestinal pH toward the acidic pH making it unfavorable for pathogenic bacteria survival. Supplementation of B. licheniformi (Trela et al, 2020), B. subtilis (Soliman et al, 2021;Bai et al, 2016), B. coagulans (Zainuddin et al, 2020), and L. lactis (Brzóska et al, 2012) improved daily gains, feed intakes, and feed efficiency of broiler chickens. B. amyloliquefaciens was able to inhibit the E. coli growth, improved villus height, and crypt depth (Ahmed et al, 2014;Hung et al, 2012).…”