Clinical assessment of copper oxide nanoparticles and black elderberry extract in therapy of avian pathogenic Escherichia coli infection in SPF chicks

Escherichia coli (E.coli) infections pose significant health risks to poultry and humans globally. In the face of antibiotic-resistant strains, metal oxide nanoparticles and plant extracts have emerged as promising alternatives. This study evaluated the effectiveness of copper oxide nanoparticles (CuO-NPs) and black elderberry extract (BEE) against E. coli O78 infection in specific pathogen-free chicks. The birds were divided into four groups: a negative control NC, a positive control (PC; challenged with E. coli O78), CuO-NPs treatment post-challenge, and BEE treatment post-challenge. Various parameters, including clinical signs, organ lesions, bacterial load, biochemical markers, and histopathology, were assessed. Both CuO-NPs and BEE demonstrated a reduction in clinical morbidity, organ damage, and E. coli counts compared to the PC. However, BEE exhibited slightly greater efficacy in alleviating liver and kidney dysfunction. Overall, CuO-NPs and BEE hold therapeutic potential against avian colibacillosis, likely acting through antimicrobial and immunomodulatory mechanisms. These findings underscore the potential of bio-based nanoparticles and plant extracts as safer, multi-modal alternatives to antibiotics for avian colibacillosis. Further optimization and mechanistic studies are needed to support their clinical application.