Silica-Calcite Sedimentary Rock (Opoka) Enhances the Immunological Status and Improves the Growth Rate in Broilers Exposed to Ochratoxin A in Feed

Mycotoxins, such as Ochratoxin A (OTA), originating from fungi like Aspergillus and Penicillium, represent serious health hazards to poultry. The use of mycotoxin-adsorbing feed additives can reduce these risks. Opoka, a porous transitional rock, shows promise as one of these additives. This study is the first to examine the effect of Opoka administered with OTA on zootechnical parameters and the immune response of chickens. A 42-day investigation examined the impact of 1% of Opoka supplementation in feed on OTA-challenged broiler chickens. Seventy-two chickens were allocated into three groups of twenty-four individuals each: a control group, an OTA-exposed (2 mg/kg feed) group, and an OTA (2 mg/kg feed) plus 1% of Opoka group. Growth and blood parameters were monitored at predetermined intervals, and comprehensive biochemical, hematological, and cytometric analyses were conducted. The study showed that OTA exposure had a negative impact on chicken weight gain. However, adding Opoka to the diet improved weight gain, indicating its potential as a protective agent. Chickens fed with Opoka also had an increased white blood cell count, which suggests an improved immune response and elevated glucose and cholesterol concentrations. These findings indicate that Opoka may be useful in mitigating health complications caused by OTA exposure in broilers.

Poly (lactic-co-glycolic acid) nanoparticle-based vaccines delivery systems as a novel adjuvant for H9N2 antigen enhance immune responses

Poly (lactic-co-glycolic acid) (PLGA) nanoparticle used as vaccine adjuvants have been widely investigated due to their safety, antigen slow-release ability, and good adjuvants activity. In this study, immunopotentiator Alhagi honey polysaccharide encapsulated PLGA nanoparticles (AHPP) and assembled pickering emulsion with AHPP as shell and squalene as core (PPAS) were prepared. Characterization of AHPP and PPAS were investigated. H9N2 absorbed nanoparticles formulations were immunized to chicken, then the magnitude and kinetics of antibody and cellular immune responses were assessed. Our results showed that PPAS had rough strawberry-like surfaces, a large number of antigens could be absorbed on their surfaces through simple mixing. Adjuvant activity of PPAS showed that, PPAS/H9N2 can induce long-lasting and high HI titers, high thymus, spleen, and bursa of fabricius organ index. Moreover, chicken immunized with PPAS/H9N2 showed a mixed high differentiation of CD4⁺ and CD8a⁺ T cell, and strong Th1 and Th2-type cytokines mRNA expression. Thus, these findings demonstrated that PPAS could induce a strong and long-term cellular and humoral immune response, and has the potential to serve as an effective vaccine delivery adjuvant system for H9N2 antigen.

It's elemental! Siliceous diatom frustules producing sarcoid-like granulomas in the subcutis

Silica granulomas have been described on the skin and are rare; however, this is the first report of a sarcoid-like granulomatous reaction because of siliceous diatom frustules in the subcutis, making this an unprecedented case. A 41-year-old female presented with a subcutaneous nodule on the right forearm clinically suggestive of cyst, foreign body, or lipoma. Excisional biopsy revealed subcutis with a sarcoid-like granulomatous reaction in a background of fibrosis, containing abundant semitransparent, exquisitely geometric particles, mildly refringent under polarized light, highlighted by phase contrast microscopy; special stains were negative for microorganisms. Definitive characterization of the peculiar fragments was accomplished by confocal laser microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy, revealing them as diatom frustules made of silicon dioxide (SiO₂ ) or silica. Diatoms are unicellular algae, their skeletons (frustules) made of silica have collected on the bottom of rivers, lakes, and oceans for thousands or millions of years and form what we know as diatomite or diatomaceous earth, which is widely used in different industries and easily available in the market. The mechanism whereby diatom frustules gained access to the patient's subcutis is enigmatic.

Wealth from waste: Diatoms as tools for phycoremediation of wastewater and for obtaining value from the biomass

Diatoms are a type of microalgae with diverse capabilities which make them useful for multiple applications. The abundance of diatoms in water bodies facilitates the removal of pollutants from wastewater originating from different industries, such as agriculture and other anthropogenic sources. The unique photosynthetic, cellular and metabolic characteristics of diatoms allows them to utilize pollutants like nitrate, iron, phosphate, molybdenum, silica, and heavy metals, such as copper, cadmium, chromium, lead, etc., which make diatoms a good option for wastewater treatment. In addition, the biomass produced by diatoms growth on wastewaters has diverse applications and can, therefore, be valuable. This review focusses on the unique capabilities of diatoms for wastewater remediation and the capture of carbon dioxide, concomitant with the generation of valuable products. Diatom biorefinery can be a sustainable solution to wastewater management, and the biomass obtained from treatment can be turned into biofuels, biofertilizers, nutritional supplements for animal production, and used for pharmaceutical applications containing bioactive compounds like EPA, DHA and pigments such as fucoxanthin.

Transgenic microalgae as bioreactors

Microalgae are unicellular organisms that act as the crucial primary producers all over the world, typically found in marine and freshwater environments. Most of them can live photo-autotrophically, reproduce rapidly, and accumulate biomass in a short period efficiently. To adapt to the uninterrupted change of the environment, they evolve and differentiate continuously. As a result, some of them evolve special abilities such as toleration of extreme environment, generation of sophisticated structure to adapt to the environment, and avoid predators. Microalgae are believed to be promising bioreactors because of their high lipid and pigment contents. Genetic engineering technologies have given revolutions in the microalgal industry, which decoded the secrets of microalgal genes, express recombinant genes in microalgal genomes, and largely soar the accumulation of interested components in transgenic microalgae. However, owing to several obstructions, the industry of transgenic microalgae is still immature. Here, we provide an overview to emphasize the advantage and imperfection of the existing transgenic microalgal bioreactors.

Fossil Shell Flour in Livestock Production: A Review

Fossil shell flour (FSF), also known as Diatomaceous earth, or diatomite, consists of amorphous silicates with important physical and chemical characteristics, including porosity and permeability, low density and thermal conductivity, tiny particle size, high surface area, solubility, hydrophobia, and absorption capabilities, which are molecular filter actors, substituting their integral cations without physical changes. The substance is nontoxic, cheap, and readily available in large quantity in many countries. Recently, FSF has been modified as additives for several uses. Recent studies have supported its use as animal growth promoter, vaccine adjuvant in livestock, water purifier, mycotoxin binder, inert dust applications in stored-pest management, pesticide, animal feed additive, as a natural source of silicon in livestock and as natural anthelmintic. Numerous advantages of FSF include its low-cost and availability, its nontoxic characteristics, and the fact that food grade diatomaceous earth is safe for human consumption. In this paper, we review the main uses of FSF in the livestock industry, with reference to similar works earlier published that elucidate their important roles.

The effect of diatomaceous earth in live, attenuated infectious bronchitis vaccine, immune responses, and protection against challenge

Live virus vaccines are commonly used in poultry production, particularly in broilers. Massive application and generation of a protective local mucosal and humoral immunity with no adverse effects is the main goal for this strategy. Live virus vaccines can be improved by adding adjuvants to boost mucosal innate and adaptive responses. In a previous study we showed that diatomaceous earth (DE) can be used as adjuvant in inactivated vaccines. The aim of this study was to test DE as adjuvant in an Ark-DPI live infectious bronchitis virus (IBV) vaccine after ocular or spray application. Titrating the virus alone or after addition of DE showed that DE had no detrimental effect on the vaccine virus. However, adding DE to the vaccine did not induce higher IgG titers in the serum and IgA titers in tears. It also did not affect the frequency of CD4⁺ T cells, CD8⁺ T cells and monocytes/macrophages in the blood and the spleen determined by flow cytometry. In addition, protection generated against IBV homologous challenges, measured by viral load in tears, respiratory signs and histopathology in tracheas, did not vary when DE was present in the vaccine formulation. Finally, we confirmed through our observations that Ark vaccines administered by hatchery spray cabinet elicit weaker immune responses and protection against an IBV homologous challenge compared to the same vaccine delivered via ocular route.

Expression of Histophilus somni IbpA DR2 protective antigen in the diatom Thalassiosira pseudonana

Increasing demand for the low-cost production of valuable proteins has stimulated development of novel expression systems. Many challenges faced by existing technology may be overcome by using unicellular microalgae as an expression platform due to their ability to be cultivated rapidly, inexpensively, and in large scale. Diatoms are a particularly productive type of unicellular algae showing promise as production organisms. Here, we report the development of an expression system in the diatom Thalassiosira pseudonana by expressing the protective IbpA DR2 antigen from Histophilus somni for the production of a vaccine against bovine respiratory disease. The utilization of diatoms with their typically silicified cell walls permitted development of silicon-responsive transcription elements to induce protein expression. Specifically, we demonstrate that transcription elements from the silicon transporter gene SIT1 are sufficient to drive high levels of IbpA DR2 expression during silicon limitation and growth arrest. These culture conditions eliminate the flux of cellular resources into cell division processes, yet do not limit protein expression. In addition to improving protein expression levels by molecular manipulations, yield was dramatically increased through cultivation enhancement including elevated light and CO₂ supplementation. We substantially increased recombinant protein production over starting levels to 1.2% of the total sodium dodecyl sulfate-extractable protein in T. pseudonana, which was sufficient to conduct preliminary immunization trials in mice. Mice exposed to 5 μg of diatom-expressed DR2 in whole or sonicated cells (without protein purification) exhibited a modest immune response without the addition of adjuvant.