جستجوی مقالات مرتبط با کلیدواژه « mycobacterium bovis » در نشریات گروه « پزشکی »

Lipoarabinomannan is one of the components of the significant structural cell surfaces of my- cobacteria and serves as an immunostimulatory factor. TNF-α and IL-12 are two examples of the anti-bacterial inflammatory cytokines that are activated and induced during infection.

In this study, mannan was extracted and processed, and then Bulb/c female mice were used in three groups, one group was given BCG vaccine, the other group was given BCG vaccine with mannan adjuvant, and a non-injected group was used as a control group. Inflammatory factors interleukin-12, TNF-α, IgG and IgM were measured in mouse serum.

The levels of the inflammatory factors interleukin-12 and TNF-α in the serum isolated from mice receiving the BCG vaccine with mannan adjuvant showed a significant difference compared to the group that received only the BCG vaccine and the control group [IL-12] and , with P≤0.05.The examination of the level of IgG immune factors in these three groups revealed a significant difference. The group that received the BCG vaccine with mannan adjuvant showed a marked contrast compared to the group that received only the BCG vaccine and the control group, with P≤0.05. The level of IgM was higher in the group that received the BCG vaccine alone compared to the adjuvant vaccine group and the control group, with P≤0.05.

Our results indicated that mice receiving the BCG vaccine with mannan adjuvant had significantly higher serum levels of IL-12, TNF-α, and IgG than the group receiving BCG alone.

The limited efficacy of BCG (bacillus Calmette–Guérin) urgently requires new effective vaccination approaches for the control of tuberculosis. Poly lactic-co-glycolic acid (PLGA) is a prevalent drug delivery system. However, the effect of PLGA-based nanoparticles (NPs) against tuberculosis for the induction of mucosal immune response is no fully elucidated. In this study, we hypothesized that intranasal immunization with culture filtrate protein-10 (CFP10)-loaded PLGA NPs (CFP10-NPs) could boost the protective immunity of BCG against Mycobacterium bovis in mice.

The recombinant protein CFP10 was encapsulated with PLGA NPs to prepare CFP10-NPs by the classical water–oil-water solvent-evaporation method. Then, the immunoregulatory effects of CFP10-NPs on macrophages in vitro and on BCG-immunized mice in vivo were investigated.

We used spherical CFP10-NPs with a negatively charged surface (zeta-potential −28.5 ± 1.7 mV) having a particle size of 281.7 ± 28.5 nm in diameter. Notably, CFP10-NPs significantly enhanced the secretion of tumor necrosis factor α (TNF-α) and interleukin (IL)-1β in J774A.1 macrophages. Moreover, mucosal immunization with CFP10-NPs significantly increased TNF-α and IL-1β production in serum, and immunoglobulin A (IgA) secretion in bronchoalveolar lavage fluid (BALF), and promoted the secretion of CFP10-specific interferon-γ (IFN-γ) in splenocytes of mice. Furthermore, CFP10-NPs immunization significantly reduced the inflammatory area and bacterial load in lung tissues at 3-week post-M. bovis challenge.

CFP10-NPs markedly improve the immunogenicity and protective efficacy of BCG. Our findings explore the potential of the airway mucosal vaccine based on PLGA NPs as a vehicle for targeted lung delivery.

Bacillus Calmette Guerin (BCG) was designed for protecting children against tuberculosis. Also, it can protect against other infectious diseases through the induction of trained immunity. Due to its heterologous protective effects, the BCG vaccine has been proposed as a treatment option for coronavirus disease-2019 (COVID-19). Epidemiological studies have found that countries without BCG vaccination policy have experienced higher mortality rates related to COVID-19 infection than those with BCG vaccination policy. However, there are some confounding factors such as age, population intensity, immigration, the pandemic phase, and data accuracy that may affect these results. Therefore, this hypothesis should be evaluated by clinical trial studies. Large-scale clinical trials are in progress to investigate if the BCG vaccine could be used as a useful tool for protection against COVID-19 infection.

Bacillus Calmette–Guérin (BCG) has been used as an intravesical product for the treatment of intermediate and high risk, non-muscle-invasive bladder cancer (NMIBC). Freeze drying technique is highly recommended for product development, however, the microorganism sensitivity to freezing and drying processes is a major chalenge which may lead to poor survival. To overcome this problem, the use of cryoprotectants in intravesical BCG formulation is required. This study was, therefre, planned to design a new formulation, using an attenuated strain of Mycobacterium bovis, which could be produced by freeze drying technique with the aim of prolonging its storage stability and increasing its efficacy as well as the ease of administration. For this purpose, sodium L-glutamate monohydrate (a commonly used stabilizer in domestic BCG suspension formulations) was replaced by lactose monohydrate. New intravesical BCG formulations, both in lyophilized and liquid forms, were eventually evaluated by moisture content assay, viable count assay, bacterial and fungal contamination, safety test and determination of bacterial concentration and O2 consumption. The results were compared with the data obtained for the conventional lyophilized and liquid products. Maximum survival rate was achieved in the presence of 10 % w/v lactose monohydrate for both liquid and lyophilized formulations when stored at less than -10 and 2-8C, respectively. In summary, the freeze-dried formulations developed with lactose monohydrate met the requirements of intravesical BCG in high viability and stability during storage.

The diagnosis of Tuberculous Meningitis (TBM) has remained a challenge due to its insidious onset and the failure of conventional diagnostic tests. The present study aimed to identify the mycobacterial pathogen in the CSF of patients with TBM and a poor prognosis.

We retrospectively recruited 224 TBM and 34 non-TBM patients admitted to the Central India Institute of Medical Sciences, Nagpur, India, in 2014. The CSF samples of these patients were subjected to a duplex PCR assay for the species-specific identification of the causative pathogen.

M. bovis and infection with M.tuberculosis were detected in 7% (18) and 32.9% (85) of the patients, respectively. Moreover, 14% (36) of the study samples were culture positive; however, the mycobacterial pathogens could not be differentiated to the species level. 

The present study findings emphasized the potentially vital importance of M. bovis identification for appropriate patient management. The obtained data also demonstrated the persistent significance of M. bovis, as a zoonotic pathogen.

Bovine tuberculosis diagnosis is usually performed by various tests with specific limitations. Mycobacterium bovis culture filtrate contains antigenic proteins that could be used to improve the sensitivity of bovine tuberculosis diagnosis. The objective of this study was to identify and purify antigenic proteins from culture filtrates of M. bovis strain AN5 for use in immunological assays.

Secreted proteins were purified from the heat-treated culture filtrate of M. bovis strain AN5. Proteins were precipitated with ammonium sulfate, fractionated by Sephadex G50 chromatography. The protein concentrations and the approximate molecular weight were determined by lowry method and 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), respectively. Immunological methods, including dot-blotting and western blotting, assessed the quality of the isolated proteins.

The quantity of antigenic proteins in the culture medium was measured at far more than 15% of the amount of proteins secreted into medium. Three main chromatographic fractions obtained and showed concentrations of proteins ranging from 14 to 60 μg/μl with molecular weights in the 10 to 180 kDa range. The purified antigens showed positive reactions to the infected cattle serum throughout dot-blotting. Western blotting revealed a total of 15 to 70 kDa molecular weight proteins.

Immunoblotting analysis made it possible to detect and recognize novel antigens that are useful for bovine tuberculosis diagnosis improvement. This is significant since non-specific reactions were not observed when we utilized serum of cattle experimentally infected with M. bovis as a polyclonal antibody.