Polymeric nanocarrier-based adjuvants to enhance a locally produced mucosal coryza vaccine in chicken.

Infectious coryza (IC) is an acute upper respiratory disease of chicken caused by Avibacterium (A.) paragallinarum. This disease results in an increased culling rate in meat chicken and a marked decrease in egg production (10% to more than 40%) in laying and breeding hens. Vaccines were first used against IC and effectively controlled the disease. Nanotechnology provides an excellent way to develop a new generation of vaccines. NPs have been widely used in vaccine design as adjuvants and antigen delivery vehicles and as antibacterial agents; thus, they can be used as inactivators for bacterial culture. In this research, the antibacterial effects of several nanoparticles (NPs), such as silicon dioxide with chitosan (SiO2-CS), oleoyl-chitosan (O.CS), silicon dioxide (SiO2), and iron oxide (Fe3O4), on A. paragallinarum were studied. Additionally, different A. paragallinarum vaccines were made using the same nanomaterials at a concentration of 400 µg/ml to help control infectious coryza disease in chicken. A concentration of 400 µg/ml of all the NPs tested was the best concentration for the inactivation of A. paragallinarum. Additionally, this study showed that the infectious coryza vaccine adjuvanted with SiO2 NPs had the highest immune response, followed by the infectious coryza vaccine adjuvanted with Fe3O4 NPs, the infectious coryza vaccine adjuvanted with SiO2-CS NPs, and the infectious coryza vaccine adjuvanted with O.CS NPs in comparison with the infectious coryza vaccine adjuvanted with liquid paraffin (a commercial vaccine).

Inactivated pentavalent vaccine against mycoplasmosis and salmonellosis for chickens.

Mycoplasma and Salmonella are serious pathogens threaten the poultry industry. This study aimed to prepare and evaluate an inactivated pentavalent vaccine targeting bacteria, including Salmonella enterica serovar Typhimurium (ST), Salmonella enterica serovar Enteritidis (SE), Salmonella enterica serovar Kentucky (SK), Mycoplasma gallisepticum (MG), and Mycoplasma synoviae (MS), from locally isolated strains. The prepared vaccine was adjuvanted with Montanide ISA70 oil and then tested for safety, sterility, and potency. The vaccine efficacy was evaluated in 110 specific pathogen-free, 1-day-old chicks, which were divided into three groups as follows: 1) vaccinated group (50 birds), which was subdivided into five subgroups of ten birds each; 2) control positive (challenged) group (50 birds), which was subdivided into five subgroups of ten birds each; and 3) control negative (blank) group, which included ten birds. Chicks in group 1 were administered the first dose of vaccine at 7 d of age followed by a booster dose after 3 wk. At 3 wk after booster vaccination, the chicks who were administered the booster dose were challenged and kept under observation until the end of the experiment when the chicks were approximately 10 wk. Details of clinical symptoms, daily mortality, weights, and postmortem lesions; serum samples; cloacal swabs; and nasal swabs were collected during the experiment. The humoral immune response to the prepared pentavalent vaccine was assessed using enzyme-linked immunosorbent assay. Our findings revealed that the prepared vaccine showed high protective antibody titers against Salmonella and Mycoplasma with 100% efficacy and no mortalities (100% survival rate) were recorded in vaccinated and challenged birds. The vaccine reduced both clinical signs and bacterial shedding post challenge in vaccinated birds in comparison with control positive group. The prepared vaccine did not affect the body weight gain of the vaccinated birds in comparison with control negative birds. The current study concluded that locally manufactured inactivated pentavalent vaccine offers protection to birds and could be employed as an effective tool along with biosecurity measures to overcome mycoplasmosis and salmonellosis in layer and breeder chicken farms in Egypt.

Evaluation of cell-mediated immunity of E.coli nanovaccines in chickens.

Nanovaccine is a revolutionary type of immunizations for various diseases that is simple to manufacture and administer. As a result, we are working to develop innovative nanovaccines against E. coli, which is capable of causing disease both inside and outside of its predilection sites, causing respiratory and systemic disease (colibacillosis).Colibacillosis is a global disease that significantly affects poultry production. The present study aims to evaluate in vivo cell-mediated immunity against a chitosan-nanovaccine from E. coli serogroups O1 and O78 to aid in limiting colibacillosis in chicken. Two hundred specific pathogen-free (SPF) three weeks old broiler chickens were used and divided into five groups: the first group inoculated with the outer membrane and flagellar antigen (OF), the second group inoculated with chitosan capsulated-outer membrane protein-flagellar antigen (CSC-O-F), the third group inoculated with chitosan loaded-outer membrane protein-flagellar antigen (CSL-O-F), the fourth group was vaccinated with (CSL-O-F-M) adjuvanted with Montanide ISA 71 RVG, and the fifth group was left as unvaccinated control. The immune response was measured by ELISA, lymphocyte proliferation test, and challenge test. The duration of immunity was also studied. The CSL-O-F-M had the highest antibody titer in an ELISA test using the O1 strain, and the CSC-O-F had the highest antibody titer in an ELISA test using the O78 strain. For both O1 and O78 strains, the CSL-O-F-M had the strongest cell-mediated immune response, which was validated by the challenge test and duration study. We recommend producing nanovaccines (CSL-O-F-M) from E.coli O1 and O78 strains as a new manufacturing vaccine based on the demonstrated results. Because it produces highly effective humoral and cell-mediated immune responses, this novel vaccine may be useful in reducing the risk of colibacillosis.