Effect of Bacillus subtilis on the microarchitectural development of the immune system in Salmonella-challenged broiler chickens

Abstract

The effect of Bacillus subtilis on the immune responses and morphometry of the immune organs was evaluated in broilers challenged with S. gallinarum. For this purpose, Salmonella-free birds (n = 240) were split into four groups with six replicates of ten birds each. Groups included an NC (negative control, non-infected + non-medicated), a PC-S (positive control, Salmonella-infected + non-medicated), an AT-S (Salmonella-infected + medicated with enrofloxacin), and a BS-S (Salmonella-infected + B. subtilis (2.0 × 10<sup>10</sup> cfu/g; 0.1 g/kg) group. On day 21, the thickness of the thymus cortex and medulla, germinal centre area of the spleen, bursal follicular length and bursal follicular area increased (P < 0.05) in the BS-S when compared to the NC and PC-S groups. On day 35, the BS-S group exhibited a higher (P < 0.05) antibody titre against the Newcastle disease virus (NDV), and cortex of the thymus was thicker (P < 0.05) compared to the other groups. A decrease in the thymus medulla thickness, germinal area of the spleen and bursal follicular number were noted in the PC-S group when compared to the other treatment groups. In conclusion, the prophylactic use of B. subtilis type probiotics alleviated the stress resulting from a Salmonella gallinarum infection and improved the immune organs development and function in infected broilers.

Different levels of single-strain probiotic (Bacillus subtilis) with proteolytic enzyme (serratiopeptidase) can be used as an alternative to antibiotic growth promoters in broiler

“…The findings of the present study are in line with the results of Sikandar et al (2021) who documented that supplementation of B. subtilis in broiler chick's production significantly improves the antibodies titer against the viral infection. The finding of the current studies is supported the by results of Mohamed et al (2022) who concluded that supplementation of B. subtilis in the broiler production significantly established the production of immunoglobulin sub-type E, A and M. Gadde et al (2017) reported that probiotics significantly improve the gut integrity by expressing the interleukin (2, 4, 10, and 11) in the poultry that leads to improvement in the immune response against the different infection in the host body.…”

Effects of encapsulated butyric acid on general performance, intestinal health, and colonization in organs of poultry infected with Salmonella Enteritidis

“…Injuries in the intestinal mucosa caused by bacteria of the genus Salmonella alter the intestinal physiology, reducing the absorption of nutrients and, consequently, the performance of the birds. Moreover, the competition between Salmonella and the host for nutrients, associated with the inflammatory response and the activation or dysregulation of the immune system, costs energy that may reduce FI and WG (Vandeplas et al, 2009;Quinteiro-Filho et al, 2012;Zhen et al, 2018;Sikandar et al, 2022).…”