Supplementing broiler diets with bacterial selenium nanoparticles enhancing performance, carcass traits, blood indices, antioxidant status, and caecal microbiota of Eimeria tenella-infected broiler chickens

Nanomedicine is a critical therapeutic approach for treating most poultry illnesses, particularly parasitic infections. Coccidiosis is a severe protozoan infection affecting poultry; the emergence of drug-resistant Eimeria strains demands the development of new, safe therapies. Consequently, the objective of this work was to investigate the efficacy of the biosynthesized selenium nanoparticles (SeNPs) by Paenibacillus polymyxa (P. polymyxa) against Eimeria tenella (E. tenella) experimental infection in broiler chickens. The prepared SeNPs absorbed the UV at 270 nm were spherical with a size of 26 nm, and had a surface negative charge of −25 mV. One hundred and fifty, 1-day-old male broiler chicks were randomly allocated into 5 groups (30 birds/group with triplicates each) as follows: T1: negative control (noninfected and nontreated with SeNPs); T2: delivered SeNPs (500 µg/kg diet) for 35 successive days, T3: E. tenella-infected (positive control birds), T4: E. tenella-infected and treated with SeNPs (500 µg/kg diet) and T5: E. tenella-infected chicks and treated with anticoccidial agent (sulfadimidine, 16% solution 8 mL/L of drinking water) for 5 successive days. At 14 d of age, each bird in infected groups was orally treated with 3 × 10(3) sporulated oocyst of E. tenella. SeNPs considerably decreased the number of oocysts in broiler feces compared to positive control and anticoccidial drug, followed by a substantial reduction of parasite phase count in the cecum (15, 10, and 8 for meronts, gamonts, and developing oocysts) when compared with positive control birds. The Eimeria experimental infection lowered the activity of antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx), and reduced glutathione (GSH) while increasing the stress parameters nitric oxide (NO) and malonaldehyde (MDA). Moreover, the production of proinflammatory (TNF-α and IL-6) and apoptotic genes (BcL2 and Cas-3) were significantly elevated. Administrating SeNPs to chicks significantly decreased oxidative stress, inflammation, and apoptotic markers in the cecum tissue. Therefore, growth performance, carcass weights, antioxidant enzymes, and blood properties of infected chicks were enhanced. The findings compared the protecting role of Se-nanoparticles against cecum damages in E. tenella-infected broilers.