Publications by authors named "Fernando Zuniga-Navarrete"

Postmodification of alginate-based microspheres with polyelectrolytes (PEs) is commonly used in the cell encapsulation field to control microsphere stability and permeability. However, little is known about how different applied PEs shape the microsphere morphology and properties, particularly . Here, we addressed this question using model multicomponent alginate-based microcapsules postmodified with PEs of different charge and structure.

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Article Synopsis
  • Bacillus thuringiensis (Bt) toxins are known for their effectiveness against certain insects, but they are typically less effective on sap-sucking insects like aphids.
  • The study focuses on the Cry toxin from Bt strain GP919, which demonstrated over 80% mortality in the aphid Myzus persicae at a concentration of 10 ng/µl, while showing no toxicity to the caterpillar Spodoptera frugiperda.
  • The research identifies a specific Cry1Cb2 protein that is lethal to aphids and suggests it could be an innovative, eco-friendly method for controlling sap-sucking pests in agriculture.
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Background: Rickettsialpox is a febrile illness caused by the mite-borne pathogen Rickettsia akari. Several cases of this disease are reported worldwide annually. Nevertheless, the relationship between the immunogenicity of R.

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The most commonly used biopesticides to control agricultural, forest and insect vectors of human diseases are derived from the bacterium Bacillus thuringiensis, which begins to produce Cry and Cyt insecticidal proteins during the onset of the sporulation phase. Some B. thuringiensis strains also produce S-layer proteins that are toxic to certain pests.

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Antibiotic resistance is a global threat with a top concern in healthcare. Doxycycline is an antibiotic highly permeable to cell membrane used for treating a broad variety of bacteria, including Coxiella burnetii. This intracellular pathogen is the causative agent of Q fever, a re-emerging zoonosis found worldwide.

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Bacillus thuringiensis (Bt) produces insecticidal proteins that have been used worldwide in the control of insect-pests in crops and vectors of human diseases. However, different insect species are poorly controlled by the available Bt toxins or have evolved resistance to these toxins. Evolution of Bt toxicity could provide novel toxins to control insect pests.

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Bacillus thuringiensis Cry toxins exert their toxic effect by specific recognition of larval midgut proteins leading to oligomerization of the toxin, membrane insertion and pore formation. The exposed domain II loop regions of Cry toxins have been shown to be involved in receptor binding. Insect cadherins have shown to be functionally involved in toxin binding facilitating toxin oligomerization.

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Bacillus thuringiensis Cry toxins recognizes their target cells in part by the binding to glycosyl-phosphatidyl-inositol (GPI) anchored proteins such as aminopeptidase-N (APN) or alkaline phosphatases (ALP). Treatment of Tenebrio molitor brush border membrane vesicles (BBMV) with phospholipase C that cleaves out GPI-anchored proteins from the membranes, showed that GPI-anchored proteins are involved in binding of Cry3Aa toxin to BBMV. A 68 kDa GPI-anchored ALP was shown to bind Cry3Aa by toxin overlay assays.

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Bacillus thuringiensis subsp. israelensis produces three Cry toxins (Cry4Aa, Cry4Ba and Cry11Aa) that are active against Aedes aegypti larvae. The identification of the rate-limiting binding steps of Cry toxins that are used for insect control in the field, such as those of B.

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