Kurkure, N. V.Panda, S.2021-03-092021-03-092020https://krishikosh.egranth.ac.in/handle/1/5810162171Colibacillosis is a prevalent bacterial disease in the poultry industry throughout the world caused by avian pathogenic Escherichia coli. The multidrug resistance in E. coli strains makes it a potential reservoir for gene resistance possessing zoonotic health risks. To combat the antibiotic resistance alternative techniques for diagnosis and treatment of E. coli are need at the moment. The present research was outlined to elucidate the therapeutic potential of metal nanoparticle mixture as an alternative for the antibiotic resistance in E. coli infection. During the research, the revival of E. coli isolates was done and confirmed by PCR. One of the E. coli isolates positive for both genes was used for challenging the broilers at the concentration of 1x 108 CFU/bird by giving 1 ml inoculum through oral route. A notable difference (P<0.01) in the efficacy of Ag nanoparticles followed by the mixed metal nanoparticle mixture was seen in the in vitro assay as compared with other metals viz. Mg, Cu, Fe, Se, Zn, Cr, Sn. In the present experiment, the addition of metal nanoparticle mixture (1- 28 days) in birds challenged with E.coli infection showed significantly (P<0.01) higher body weight, lower feed intake and comparatively better FCR in respect with other groups. Histopathological lesions in the lungs revealed congestion, haemorrhages, exudates and infiltration of leucocytes. Severe pericarditis and perihepatitis were evident. Peritonitis with distended caeca was observed. Haemorrhages in lamina propria, disruption of villi, sloughing of mucosa along with mononuclear infiltration of cells was found in the intestine. Nonetheless, significant (P<0.01) reduction in intensity of the lesions and bacterial colonization in intestine of N3 fed with nanoparticles from the 10th day of age was observed at 21st day of age. The result of present study indicates that metal nanoparticles can be further explored as an alternative to antibiotic growth promoters.EnglishThesis