Mannheimia haemolytica is responsible for considerable economic losses to sheep, goats, and cattle and other livestock industries in Egypt. This study aimed to evaluate the effectiveness of a newly developed gamma irradiation vaccine against Mannheimia haemolytica in comparison to a formalin-killed vaccine. Three groups of rabbits were used in this study. Group 1 animals were inoculated with 4 × 10 9 bacterial cells per dose of the formalin-killed vaccine. Group 2 was inoculated with 2 × 10 9 bacterial cells per dose of gamma-irradiated vaccine. Group 3 (control group) was injected with 2 mL of sterile PBS. The vaccines were injected subcutaneously into experimental animals twice with 3-week intervals between inoculations. Three weeks after the second vaccination dose, the animals in all groups were infected with M. haemolytica twice with 1-week intervals between inoculations. Blood samples were collected weekly after the first vaccination until one week after the second M. haemolytica infection challenge. ELISA results revealed that the gamma irradiation vaccine developed in this study provided protective effects that reached high levels at the time of challenge. Furthermore, the second dose of gamma irradiation vaccine could act as a booster dose resulting in increased antibody production.
Skin ulcers are non‐healed wounds caused by inflammation of epidermis up to the dermis, which causes pain and limits body movements, significantly reducing quality of life. Amniotic membrane is a placental collagenous biomaterial with many biological and mechanical properties important for tissue engineering and regenerative medicine. The aim of this work is to evaluate the efficacy of topical antibiotic washing followed with irradiated human amniotic membrane (iHAM) dressing for treating five different types of ulcers. The current study included 15 patients who were recruited from the outpatient clinic of the Egyptian Atomic Energy Authority. Follow up of all treated cases that completed the regimen was up to 3 months. The clinical progression of all treated ulcers was quantitatively evaluated by computerized estimation of the wound size reduction based on 3D image analysis. All cases in this study showed great outcomes within several weeks of treatment depending on wound infection, ulcer depth and size, period of healing disorder, age, blood glycemia, and other clinical criteria. Patients' questionnaires revealed that pain was controlled by the first time of treatment. After 1 week post‐treatment, granulation tissue was generated and observed in all patients, and all microbial colonies have been eliminated from wounds with previous infection. The current study indicated that the dressing of ulcers with iHAM induces fast healing without complication.
Background and Aim: Vaccines are one of the important tools for fighting diseases and limiting their spread. The development of vaccines with high efficacy against diseases is essential. Ionizing radiation is the method used for the preparation of the irradiated gamma Mannheimia haemolytica vaccine. The study aimed to measure the metabolic activity and electron microscopic examination of the irradiated bacterial cells and immunological efficiency of different preparations of the irradiated M. haemolytica vaccine.
Materials and Methods: The irradiated vaccines were prepared in three forms at a dose of 2×109 colony-forming unit (CFU) (irradiated M. haemolytica, trehalose irradiated M. haemolytica, and trehalose lyophilized irradiated M. haemolytica). The formalin-killed vaccine was prepared at a dose of 2×109 CFU. Scanning electron microscopy was used to determine the difference between the non-irradiated bacterial cells and the bacterial cells exposed to gamma radiation. The metabolic activity of the irradiated bacterial cells was measured using the Alamar blue technique. Rabbits were divided into five groups (control, vaccinated groups with the formalin-killed vaccine, irradiated bacterial cells without trehalose, trehalose irradiated bacteria, and trehalose lyophilized irradiated bacterial cells). The rabbits were subcutaneously inoculated twice in 2-week intervals. Enzyme-linked immunosorbent assay, interferon-gamma (IFNγ), and interleukin 4 (IL4) assays were used to evaluate the vaccines' immunological efficiency in rabbits.
Results: The metabolic activity tests showed that the bacterial cells exposed to gamma radiation at the lowest lethal dose have metabolic activity. The difference in the metabolic activity between preparations of the irradiated bacterial cells varied according to the cell concentration and incubation time. The highest level of metabolic activity was 8 h after incubation in the nutrient broth medium compared with 4 and 18 h. The scanning electron microscopy of irradiated bacterial cells showed a cavity at the bacterial cell center without rupture of the surrounding cell membrane compared to the non-irradiated bacterial cells. The antibody level in the groups vaccinated with the different preparations of the irradiated bacterial cells was high compared with the control and formalin-killed vaccine groups. The level of the IFNγ showed an increase after the second dose in the group vaccinated with irradiated bacterial cells without trehalose compared with the other groups. The IL4 level in the vaccinated groups with the irradiated bacterial cells without trehalose, irradiated bacterial cells with trehalose, and trehalose lyophilized irradiated bacterial cells were at a high level when compared with the formalin-killed vaccinated group and control group after the second inoculation.
Conclusion: The irradiated M. haemolytica vaccine provides a wide range of humoral and cellular immunity. This study showed high immunological efficiency in rabbits inoculated with the irradiated M. haemolytica vaccine that was shown in the high levels of antibodies (IFNγ and IL4) compared with the group treated with the formalin-killed vaccine. The second dose of irradiated M. haemolytica vaccine is an immune booster that gives the irradiated vaccine a long-acting immunological efficiency.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.