In vivo antibacterial activity of chitosan nanoparticles against Clostridium perfringens-induced necrotic enteritis in broilers

Necrotic enteritis (NE) is a major disease affecting broiler productivity, primarily caused by Clostridium perfringens. The extensive use of antibiotics to control NE has led to concerns about antimicrobial resistance and food safety, highlighting the need for safe and effective alternatives. Chitosan nanoparticles (CsNPs) have emerged as promising candidates due to their antibacterial, biodegradable, and nontoxic properties. This study aimed to evaluate the therapeutic potential of CsNPs against C. perfringens infection in broilers by assessing clinical signs, mortality, growth performance, bacterial load, immune response, and histopathological changes. Sixty 1-day-old Ross 308 chicks were randomly divided into four groups (15 birds each): G1 (negative control), G2 (C. perfringens-infected), G3 (infected + CsNPs), and G4 (CsNPs only). Birds in G2 and G3 were orally inoculated with C. perfringens (4×10⁸ CFU/mL) for two consecutive days, while CsNPs (250 µg/bird) were administered to G3 and G4. During the experiment, the birds were assessed for growth performance, intestinal microbial loads, immune organ indexes, and histopathological lesions. Over the 35-day trial, CsNPs treatment significantly improved body weight (BW), body weight gain (BWG), and feed conversion ratio (FCR) in G3 and G4 compared to G2 (P < 0.05). CsNPs reduced clinical signs and mortality and markedly decreased intestinal colonization by C. perfringens. Immune organ indices (spleen, bursa, and thymus) were significantly enhanced in CsNP-treated birds. Histopathological examination revealed that CsNPs mitigated lesions in the intestine, liver, and lymphoid organs. Chitosan nanoparticles effectively reduced the severity of necrotic enteritis in broilers, improving growth performance, intestinal health, and immune response. These findings indicate that CsNPs could serve as a safe, natural, and sustainable alternative to antibiotics for controlling C. perfringens infections in poultry.