Search results for "endotoxin"
showing 10 items of 144 documents
Insecticidal Activity of Bacillus thuringiensis Proteins against Coleopteran Pests
2020
Bacillus thuringiensis is the most successful microbial insecticide agent and its proteins have been studied for many years due to its toxicity against insects mainly belonging to the orders Lepidoptera, Diptera and Coleoptera, which are pests of agro-forestry and medical-veterinary interest. However, studies on the interactions between this bacterium and the insect species classified in the order Coleoptera are more limited when compared to other insect orders. To date, 45 Cry proteins, 2 Cyt proteins, 11 Vip proteins, and 2 Sip proteins have been reported with activity against coleopteran species. A number of these proteins have been successfully used in some insecticidal formulations and…
Constitutive Activation of the Midgut Response to Bacillus thuringiensis in Bt-Resistant Spodoptera exigua
2010
Bacillus thuringiensis is the most effective microbial control agent for controlling numerous species from different insect orders. The main threat for the long term use of B. thuringiensis in pest control is the ability of insects to develop resistance. Thus, the identification of insect genes involved in conferring resistance is of paramount importance. A colony of Spodoptera exigua (Lepidoptera: Noctuidae) was selected for 15 years in the laboratory for resistance to Xentari (TM), a B. thuringiensis-based insecticide, reaching a final resistance level of greater than 1,000-fold. Around 600 midgut ESTs were analyzed by DNA-macroarray in order to find differences in midgut gene expression …
Effects of Bacillus thuringiensis δ-Endotoxins on the Pea Aphid ( Acyrthosiphon pisum )
2009
ABSTRACT Four Bacillus thuringiensis δ-endotoxins, Cry3A, Cry4Aa, Cry11Aa, and Cyt1Aa, were found to exhibit low to moderate toxicity on the pea aphid, Acyrthosiphon pisum , in terms both of mortality and growth rate. Cry1Ab was essentially nontoxic except at high rates. To demonstrate these effects, we had to use exhaustive buffer-based controls.
Efficacy and Resistance Management Potential of a Modified Vip3C Protein for Control of Spodoptera frugiperda in Maize
2018
AbstractA modified Vip3C protein has been developed that has a spectrum of activity that has the potential to be commercially useful for pest control, and shows good efficacy against Spodoptera frugiperda in insect bioassays and field trials. For the first time Vip3A and Vip3C proteins have been compared to Cry1 and Cry2 proteins in a complete set of experiments from insect bioassays to competition binding assays to field trials, and the results of these complementary experiments are in agreement with each other. Binding assays with radiolabelled toxins and brush border membrane vesicles from S. frugiperda and Helicoverpa armigera show that the modified Vip3C protein shares binding sites wi…
Hetero-oligomerization of Bacillus thuringiensis Cry1A proteins enhance binding to the ABCC2 transporter of Spodoptera exigua
2021
The ATP binding cassette (ABC) transporters are membrane proteins that can act as putative receptors for Cry proteins from Bacillus thuringiensis (Bt) in the midgut of different insects. For the beet armyworm, Spodoptera exigua, ABCC2 and ABCC3 have been found to interact with Cry1A proteins, the main insecticidal proteins used in Bt crops, as well as Bt-based pesticides. The ABCC2 has shown to have specific binding towards Cry1Ac and is involved in the toxic process of Cry1A proteins, but the role of this transporter and how it relates with the Cry1A proteins is still unknown. Here, we have characterized the interactions between the SeABCC2 and the main proteins that bind to the receptor. …
Bevacizumab diminishes inflammation in an acute endotoxin-induced uveitis model
2017
Este artículo se encuentra disponible en la página web de la revista en la siguiente URL: https://www.frontiersin.org/articles/10.3389/fphar.2018.00649/full Introduction: Uveitis is an eye disease characterized by inflammation of the uvea and an early and exhaustive diagnosis is essential for its treatment. The aim of our study is to assess the potential toxicity and anti-inflammatory efficacy of Bevacizumab in an experimental uveitis model by subcutaneously injecting lipopolysaccharide into Lewis rats and to clarify its mechanism. Material and Methods: Blood–aqueous barrier integrity was assessed 24 h after endotoxin-induced uveitis (EIU) by analyzing two parameters: cell count and protein…
Host-based lipid inflammation drives pathogenesis in Francisella infection
2017
Mass spectrometry imaging (MSI) was used to elucidate host lipids involved in the inflammatory signaling pathway generated at the host-pathogen interface during a septic bacterial infection. Using Francisella novicida as a model organism, a bacterial lipid virulence factor (endotoxin) was imaged and identified along with host phospholipids involved in the splenic response in murine tissues. Here, we demonstrate detection and distribution of endotoxin in a lethal murine F. novicida infection model, in addition to determining the temporally and spatially resolved innate lipid inflammatory response in both 2D and 3D renderings using MSI. Further, we show that the cyclooxygenase-2-dependent lip…
Mediterranean diet and prudent diet are both associated with low circulating esterified 3-hydroxy fatty acids, a proxy of LPS burden, among older adu…
2021
Background LPS-type endotoxins, naturally found in the gut microbiota, are recognized as triggers of inflammation and emerge as detrimental factors of healthy aging. Nutrition represents a promising strategy to reduce LPS burden, yet little is known about the relation of diet to circulating LPS concentrations. Objective The aim was to evaluate the associations between food groups, dietary patterns, and circulating 3-hydroxy fatty acids (3-OH FAs), a proxy of LPS burden. Methods In a cross-sectional study of 698 French older community-dwelling individuals, 3-OH FA concentrations were measured by LC-tandem MS. Dietary patterns were determined using food-frequency questionnaires. Adherence to …
Editorial for Special Issue: The Insecticidal Bacterial Toxins in Modern Agriculture.
2017
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Ephestia kuehniella tolerance to Bacillus thuringiensis Cry1Aa is associated with reduced oligomer formation
2016
The basis of the different susceptibility of Ephestia kuehniella to the Cry1Aa and Cry1Ac δ-endotoxins from Bacillus thuringiensis kurstaki BNS3 was studied. Both toxins bound specifically to the BBMV of E. kuehniella. The result of the ligand blot showed that Cry1Ac bound to three putative receptors of about 100, 65 and 80 kDa and Cry1Aa interacted only with a 100 kDa protein. Pronase digestion of the BBMV-bound toxins was used to analyze the toxin insertion. Both toxins inserted into the BBMV as monomers however, a 14 kDa peptide of α4-α5 which correspond to the oligomeric form of this peptide was detected in case of Cry1Ac only. Analysis of the in vitro oligomerisation of these toxins in…