TY - BOOK AU - Basma Mohamed Hamed Ahmed AU - Eman Ragab Mohamed Mostafa , AU - Mona Ibrahem Elenbaawy , TI - The vaccines and their potential impact on antimicrobial resistance / PY - 2022/// CY - Cairo : PB - Basma Mohamed Hamed Ahmed , KW - Vaccines KW - Antimicrobial Resistance KW - Escherichia Coli KW - Poultry N1 - Thesis (M.Sc. ) - Cairo University - Faculty of Veterinary Medicine - Department of Microbiology; Issued also as CD N2 - Antimicrobial resistance (AMR) is now recognized as a major threat to global health. The present work aims to study the role of vaccine against AMR in broiler chickens using live avirulent multi-drug resistant E. coli vaccine also, investigate the additive effect of chitosan nanoparticles either as encapsulated or loaded form in another two live inactivated E. coli vaccine. Different samples from internal organs were collected from broiler from 10-38 day old. APEC was isolated by conventional culture methods and VITEK@ 2 COMPAT (bioMérieux, France) with prevalence ratio 67.5 %. Genes associated with virulence (iutA, fimC, and papC) were identified by PCR with the prevalence of 84.4%, 74%, and 54.8% of cases, respectively. Concerning antibiotic sensitivity test among the most resistant drugs, the highest rate of resistance was against Ampicillin (AM) (100%), Trimethoprim-Sulfamethoxazole (80%) Ampicillin-sulbactam (AMS) (78.5), Ceftazidime (CAZ) 75.5%, cefepime (CPM) 74 %. The vaccinal strain was selected to be avirulent and multidrug resistant. Four groups were designed for E. coli experimental vaccinal trial. The first was a negative control, the second was chitosan capsulated-antigen, the third was chitosan loaded-Ag, and the last group was immunized with live avirulent strain. Experiment vaccination revealed that antibody titer was measured by indirect ELISA and confirmed results by MAT shows that Only group 2 and 3 Significantly produced the highest response among groups. Also, the recovery of APEC from internal organs was the lowest in group 2,3 in comparison with group 4. It could be concluded that, administration of E. coli killed vaccine either loaded or encapsulated with chitosan nanoparticles promoted humeral immune response and antibody production as well as reduced APEC challenge loads. Also, E. coli vaccines based on chitosan are therefore a viable alternative to current vaccines for poultry ER -