Antibacterial effects of copper oxide nanoparticles against E. coli induced infection in broilers

Nanoparticles are emerging as a substitute to antibiotics to mitigate antimicrobial resistance. To check the in-vivo antibacterial activity of CuO-nanoparticles against E. coli-induced infection, 90 day-old birds were kept under similar condition for first 18 days during brooding phase. Then were randomly divided into six groups (control negative, control positive, colistin, CuO-NPs 20, 30 and 40 mg/kg) with 15 birds in each group. All the birds except the negative control group were given infection with 0.2 ml E. coli inoculum having a suspension concentration of 10⁷ CFU/ml through Intramuscular route. After the appearance of clinical signs, respective treatments were given for 6 days. Five birds were slaughtered after 7 days post-infection and other five birds were slaughtered at 11th day post infection. The live and carcass weight of the bird were recorded on each sampling. The blood samples were collected and serum was separated to perform the immune parameters at the time of slaughtering. Histopathological samples (spleen, bursa and thymus) were also taken and fixed in 10% neutral buffered formalin. The results indicated that the relative weight of spleen was significantly improved in the CuO-NPs treated groups as compared to control group. The antibody response against ND and sheep RBC’s showed non-significant difference from control positive group. The nanoparticles treated groups showed significantly (P < 0.05) improved phagocytic and lymphoproliferative responses. The gross and histopathological studies revealed significant (P < 0.05) improvement in treatment groups than control positive group with a non-significant difference from control negative group. The group treated with CuO-NPs 40 mg/kg showed almost similar results as that of antibiotic treated group. It was concluded that CuO-NPs had antibacterial affect and can be used as an antibiotic substitute against colibacillosis.