RESUMO
PURPOSE: Brucella spp. is a zoonosis that causes undulant fever in humans and abortion in livestock worldwide. Lately, it was conveyed that vaccines developed by irradiation have induced a strong cellular and humoral immune response which have made these types of vaccines highly effective. MATERIALS AND METHODS: In this study, we aimed to use the gamma-irradiated B. ovis as a vaccine and to study the humoral immune response and cytokines production in order to evaluate it for protecting mice against B. abortus 544, B. melitensis 16M, and B. ovis. RESULTS: The humoral immune response in immunized mice with gamma-irradiated B. ovis showed a lasting for 8 weeks after immunization. Moreover, immunoglobulin G (IgG), IgG1, IgG2a, and IgG2b isotypes antibodies against B. ovis were observed after 4 and 8 weeks of the last immunization. It was noticed that the production of tumor necrosis factor-α, interferon-γ, and interleukin (IL)-10 continued after 4 and 8 weeks by splenocytes from immunized BALB/c mice, while no production of IL-4 or IL-5 was observed. CONCLUSION: Our results indicate that the protection of BALB/c mice against B. melitensis 16M, B. abortus 544, and B. ovis was induced and the developed vaccine at our laboratory could stimulate similar protection to those induced by the traditional vaccine.
RESUMO
BACKGROUND: Despite the medical discoveries of different medicines and advanced ways of treatment, statistics have shown that the number of patients is increasing. This may be due to chemical drugs used in healthcare, agriculture, and diets. This soaring demand in medicines urges us to look for natural sources such as aromatic plants and essential oils, which are rich in efficient compounds. METHODS: Extraction of essential oils was performed using a Clevenger-type apparatus. Identification was achieved using the GC-FID technique. Confirmation was made using the GC-MS technique, and isolation was done using a preparative HPLC, equipped with an aliquots collector. The microdilution broth susceptibility assay was utilized to determine minimum inhibitory concentrations (MICs). RESULTS: Our in vitro study demonstrated the antibacterial activity of the Thymus syriacus Boiss essential oil and its components against the tested isolates at levels between 0.375 and 50 µl/ml. The main components of the T. syriacus essential oil were carvacrol, γ-terpinene, and ß-caryophyllene. MIC90 values for the T. syriacus essential oil against the gram-negative organisms varied between 3.125 and 12.5 µl/ml. The most effective components against the gram-negative bacteria were thymol, carvacrol, dihydro-carvon, and linalool respectively. CONCLUSIONS: The T. syriacus essential oil and some of its components exhibited very good inhibitory effects against Syrian gram-negative isolates.
