| effects of carriers, emulsifiers, and biopesticides for direct silk treatments on caterpillar feeding damage and ear development in sweet corn. | in the northeastern united states, control of lepidopteran pests of sweet corn, particularly corn earworm [helicoverpa zea (boddie)], is difficult using organic methods. the direct application of corn oil and bacillus thuringiensis (bt) to corn silk has been shown to reduce ear damage from corn earworm in past studies; these studies sought to optimize this method by evaluating additional carrier and biopesticide mixtures that comply with the united states federal insecticide, fungicide, and rode ... | 2017 | 28073976 |
| cry3bb1-resistant western corn rootworm, diabrotica virgifera virgifera (leconte) does not exhibit cross-resistance to dvsnf7 dsrna. | there is a continuing need to express new insect control compounds in transgenic maize against western corn rootworm, diabrotica virgifera virgifera (leconte) (wcr). in this study three experiments were conducted to determine cross-resistance between the new insecticidal dvsnf7 dsrna, and bacillus thuringiensis (bt) cry3bb1; used to control wcr since 2003, with field-evolved resistance being reported. laboratory susceptible and cry3bb1-resistant wcr were evaluated against dvsnf7 dsrna in larval ... | 2017 | 28060922 |
| biopolymer microencapsulations of bacillus thuringiensis crystal preparations for increased stability and resistance to environmental stress. | parasporal crystals synthesized by bacillus thuringiensis (bt) have been widely used as microbial pesticides because of their toxicity to the larval stages of specific insects. however, parasporal crystals can be damaged by environmental stresses, such as high temperature, ultraviolet radiation, and desiccation. to reduce environmental susceptibility of parasporal crystals and extend the duration of their activity, we developed a new type of protection by making microcapsules of crystals (mcs). ... | 2017 | 28050633 |
| spatio-temporal variation in landscape composition may speed resistance evolution of pests to bt crops. | transgenic crops that express insecticide genes from bacillus thuringiensis (bt) are used worldwide against moth and beetle pests. because these engineered plants can kill over 95% of susceptible larvae, they can rapidly select for resistance. here, we use a model for a pyramid two-toxin bt crop to explore the consequences of spatio-temporal variation in the area of bt crop and non-bt refuge habitat. we show that variability over time in the proportion of suitable non-bt breeding habitat, q, or ... | 2017 | 28046073 |
| structural complexity of filaments formed from the actin and tubulin folds. | from yeast to man, an evolutionary distance of 1.3 billion years, the f-actin filament structure has been conserved largely in line with the 94% sequence identity. the situation is entirely different in bacteria. in comparison to eukaryotic actins, the bacterial actin-like proteins (alps) show medium to low levels of sequence identity. this is extreme in the case of the parm family of proteins, which often display less than 20% identity. parms are plasmid segregation proteins that form the polym ... | 2016 | 28042378 |
| field-evolved resistance in corn earworm to cry proteins expressed by transgenic sweet corn. | transgenic corn engineered with genes expressing insecticidal toxins from the bacterium bacillus thuringiensis (berliner) (bt) are now a major tool in insect pest management. with its widespread use, insect resistance is a major threat to the sustainability of the bt transgenic technology. for all bt corn expressing cry toxins, the high dose requirement for resistance management is not achieved for corn earworm, helicoverpa zea (boddie), which is more tolerant to the bt toxins. | 2016 | 28036388 |
| transferrin impacts bacillus thuringiensis biofilm levels. | the present study examined the impact of transferrin on bacillus thuringiensis biofilms. three commercial strains, an environmental strain (33679), the type strain (10792), and an isolate from a diseased insect (700872), were cultured in iron restricted minimal medium. all strains produced biofilm when grown in vinyl plates at 30°c. b. thuringiensis 33679 had a biofilm biomass more than twice the concentration exhibited by the other strains. the addition of transferrin resulted in slightly incre ... | 2016 | 28025643 |
| interaction of transgenic and natural insect resistance mechanisms against spodoptera littoralis in cotton. | insect-resistant transgenic plants that express insecticidal cry proteins from bacillus thuringiensis (bt) are grown on millions of hectares worldwide. while these proteins are efficient in controlling key lepidopteran pests, not all pests are affected and the development of resistance in target pests is always a concern. these shortcomings could be addressed by exploiting the natural insect resistance of cotton, especially inducible terpenoids such as gossypol. | 2016 | 28019063 |
| incidental mutations occur frequently during transposon mutagenesis. | transposon mutagenesis and subsequent phenotype-driven screening have been extensively used to annotate gene function and uncover the mechanisms of biological phenomena. during this process, the resulting phenotypic differences are specifically attributable to the disrupted genes. in this study, the complementation of the mini-tn10 transposon-disrupted gene gntp did not restore the germination ability of the bacillus thuringiensis mt1518-1 mutant to the wild-type level. genome sequencing identif ... | 2017 | 28011697 |
| activity of selected formulated biorational and synthetic insecticides against larvae of helicoverpa armigera (lepidoptera: noctuidae). | this work studied 17 insecticides belonging to nucleopolyhedrovirus (npv), bacillus thuringiensis (bt kurstaki and bt aizawai), benzoylureas (insect growth regulators [igrs]), carbamates, organophosphates, spinosyns, and diamides against larvae of helicoverpa armigera (hübner), invasive species in the south american continent. larvae of different instars were fed for 7 d with untreated or insecticide-treated diets. mortality was recorded daily for 7 d, and surviving larvae were individually weig ... | 2017 | 28011685 |
| low-dose effects: nonmonotonic responses for the toxicity of a bacillus thuringiensis biocide to daphnia magna. | currently, there is a trend toward an increasing use of biopesticides assumed to be environmentally friendly, such as bacillus thuringiensis (bt). studies of the bt toxicity to nontarget organisms have reported low effects at high exposure levels, which is interpreted as indicating negligible risk to nontarget organisms. we investigated the response of the nontarget organism daphnia magna to waterborne dipel es, a globally used bt formulation. neonates and adults were exposed for 48 h to a wide ... | 2017 | 28001053 |
| a return to the pore - dissecting bacillus thuringiensis toxin mode of action via voltage clamp experiments. | pore-forming toxins from bacillus thuringiensis are increasingly used in crop protection, but evolution of resistance in crop pests threatens their continued deployment. a study by tanaka et al. shows how voltage clamp experiments that quantify pore formation can be used to dissect toxin mode of action, thereby revealing unexpected complexities that could be exploited to counter resistance. | 2016 | 27995777 |
| reproductive cost associated with juvenile hormone in bt-resistant strains of helicoverpa armigera (lepidoptera: noctuidae). | transgenic bacillus thuringiensis (bt) crops are increasingly significant in pest control, but resistance development of target pests is a major issue in the sustainable deployment of bt crops. the fitness cost of resistance in target pests is regarded as one of the main factors delaying resistance when adopting the refuge strategy. in this study, we compared the life-history traits of three independent sets of helicoverpa armigera (hübner, 1809) adults, of each there were a susceptible populati ... | 2016 | 27986942 |
| [effectiveness of three biological larvicides and of an insect growth regulator against anopheles arabiensis in senegal]. | urban malaria is a major public health problem in africa. in senegal, the environmental changes seem to favor the persistence of malaria transmission in dakar suburbs by creating, throughout the year, potential breeding sites of malaria vectors. in such a situation and in a context of a growing threat of insecticide resistance in anopheline vectors, the larval control making use of products from biological origin or growth regulators could represent an additional tool to the current strategies d ... | 2016 | 27942991 |
| insecticidal specificity of cry1ah to helicoverpa armigera is determined by binding of apn1 via domain ii loops 2 and 3. | bacillus thuringiensis cry1ah protein is highly toxic against helicoverpa armigera but shows no toxicity against bombyx mori larvae. in contrast, the closely related cry1ai toxin showed the opposite phenotype: high activity against b. mori but no toxicity against h. armigera. analysis of binding of cry1ah to brush border membrane vesicle (bbmv) proteins from h. armigera and b. mori by surface plasmon resonance revealed association of toxin binding with insect specificity. pulldown experiments id ... | 2017 | 27940541 |
| a p-glycoprotein is linked to resistance to the bacillus thuringiensis cry3aa toxin in a leaf beetle. | chrysomela tremula is a polyvoltine oligophagous leaf beetle responsible for massive attacks on poplar trees. this beetle is an important model for understanding mechanisms of resistance to bacillus thuringiensis (bt) insecticidal toxins, because a resistant c. tremula strain has been found that can survive and reproduce on transgenic poplar trees expressing high levels of the cry3aa bt toxin. resistance to cry3aa in this strain is recessive and is controlled by a single autosomal locus. we used ... | 2016 | 27929397 |
| microbial degradation of total petroleum hydrocarbons in crude oil: a field-scale study at the low-land rainforest of ecuador. | a field-level feasibility study was conducted to determine total petroleum hydrocarbon (tph)-degrading potential of two bacterial strains, bacillus thuringiensis b3 and b. cereus b6, and two fungi, geomyces pannorum hr and geomyces sp. strain hv, all soil isolates obtained from an oil field located in north-east region of ecuador. crude oil-treated soil samples contained in wooden boxes received a mixture of all the four microorganisms and were incubated for 90 days in an open low-land area of a ... | 2016 | 27928937 |
| field effectiveness of microbial larvicides on mosquito larvae in malaria areas of botswana and zimbabwe. | the successful control of malaria vectors requires the control of both the larval and adult stages. the adult control methods through indoor residual spraying (irs) and use of long-lasting insecticidal nets (llins) continue to be widely used with some high measure of success. larval control methods are also being used by a number of national malaria control programmes (nmcps) with limited understanding of its contribution. larval control might be needed in some areas to move from malaria control ... | 2016 | 27923385 |
| validation of adam10 metalloprotease as a bacillus thuringiensis cry3aa toxin functional receptor in colorado potato beetle (leptinotarsa decemlineata). | bacillus thuringiensis parasporal crystal proteins (cry proteins) are insecticidal pore-forming toxins that bind to specific receptor molecules on the brush border membrane of susceptible insect midgut cells to exert their toxic action. in the colorado potato beetle (cpb), a coleopteran pest, we previously proposed that interaction of cry3aa toxin with a cpb adam10 metalloprotease is an essential part of the mode of action of this toxin. here, we annotated the gene sequence encoding an adam10 me ... | 2017 | 27918112 |
| co-metabolism of substrates by bacillus thuringiensis regulates polyhydroxyalkanoate co-polymer composition. | polyhydroxyalkanoate (pha) production by bacillus thuringiensis egu45 was studied by co-metabolism of crude glycerol (cg) (1%, v/v), glucose (0.05-0.5%, w/v) and propionic acid (0.05-0.5%, v/v) under batch (shake flask) culture conditions. glycerol+pa combination resulted in 15-100mg/l pha co-polymers with a hv content of 33-81mol%. the addition of nh4cl (0.5%, w/v) to cg+pa enhanced pha production by 1.55-fold, with a hv content of 58-70mol%. the time period of incubation of pa to the feed: cg+ ... | 2017 | 27914782 |
| water influx via aquaporin directly determines necrotic cell death induced by the bacillus thuringiensis cry toxin. | the bacillus thuringiensis cry toxin causes swelling and necrosis in insect cells, but the route(s) and significance of the water influx involved in its cytotoxicity are unclear. here, we assessed the role of aquaporins (aqps), known as water channels, in cry toxin intoxication. an aqp inhibitor did not interfere with any known process to form the toxin pore, but it diminished the cell swelling and loss of membrane integrity induced by the cry toxin. overexpression of aqps facilitated water infl ... | 2017 | 27914170 |
| response of three cyprinid fish species to the scavenger deterrent factor produced by the mutualistic bacteria associated with entomopathogenic nematodes. | the symbiotic bacteria, photorhabdus and xenorhabdus associated with entomopathogenic nematodes (epns) in the genera heterorhabditis and steinernema, respectively, produce a compound(s) called the scavenging deterrent factor (sdf). sdf deters a number of terrestrial insect scavengers and predators and one bird species from feeding on host insects killed by the nematode-bacterium complex but has not been tested against aquatic vertebrates. moreover, the heterorhabditis-photorhabdus association is ... | 2017 | 27908637 |
| triphenyltin degradation and proteomic response by an engineered escherichia coli expressing cytochrome p450 enzyme. | although triphenyltin (tpt) degradation pathway has been determined, information about the enzyme and protein networks involved was severely limited. to this end, a cytochrome p450 hydroxylase (cyp450) gene from bacillus thuringiensis was cloned and expressed in escherichia coli bl21 (de3), namely e. coli pet32a-cyp450, whose dosage at 1gl(-1) could degrade 54.6% tpt at 1mgl(-1) within 6 d through attacking the carbon-tin bonds of tpt by cyp450. sequence analysis verified that the cyp450 gene ha ... | 2017 | 27907843 |
| correction: necrotrophism is a quorum-sensing-regulated lifestyle in bacillus thuringiensis. | [this corrects the article doi: 10.1371/journal.ppat.1002629.]. | 2016 | 27898733 |
| ephestia kuehniella tolerance to bacillus thuringiensis cry1aa is associated with reduced oligomer formation. | 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 ... | 2017 | 27888109 |
| the domain ii loops of bacillus thuringiensis cry1aa form an overlapping interaction site for two bombyx mori larvae functional receptors, abc transporter c2 and cadherin-like receptor. | information about the receptor-interaction region of cry toxins, insecticidal proteins produced by bacillus thuringiensis, is needed to elucidate the mode of action of cry toxins and improve their toxicity through protein engineering. we analyzed the interaction sites on cry1aa with abc transporter c2 (abcc2), one of the most important cry1a toxin receptors. a competitive binding assay revealed that the bombyx mori abcc2 (bmabcc2) cry1a binding site was the same as the btr175 binding site, sugge ... | 2017 | 27888075 |
| interactions among triphenyltin degradation, phospholipid synthesis and membrane characteristics of bacillus thuringiensis in the presence of d-malic acid. | degradation pathway and surface biosorption of triphenyltin (tpt) by effective microbes have been investigated in the past. however, unclear interactions among membrane components and tpt binding and transport are still obstacles to understanding tpt biotransformation. to reveal the mechanism involved, the phospholipid expression, membrane potential, cellular mechanism and molecular dynamics between tpt and fatty acids (fas) during the tpt degradation process in the presence of d-malic acid (dma ... | 2017 | 27886543 |
| dr. alois huger - laying the foundations for an integrated insect pathology. | dr. rer. nat. alois m. huger had a long and distinguished career at the institut für biologische schädlingsbekämpfung (institute for biological pest control) darmstadt, germany, where he became one of the world's leading insect pathologists. he applied his experience and understanding of insect tissues and specialist skills in microscopy to diagnosis and elucidation of the pathology of insect diseases. during his career he discovered the oryctes nudivirus and bacillus thuringiensis subsp. tenebr ... | 2017 | 27871814 |
| transgenic bt cotton does not disrupt the top-down forces regulating the cotton aphid in central china. | top-down force is referred to arthropod pest management delivered by the organisms from higher trophic levels. in the context of prevalent adoption of transgenic bt crops that produce insecticidal cry proteins derived from bacillus thuringiensis (bt), it still remains elusive whether the top-down forces are affected by the insect-resistant traits that introduced into the bt crops. we explored how bt cotton affect the strength of top-down forces via arthropod natural enemies in regulating a non-t ... | 2016 | 27870914 |
| toxicity of cry1a toxins from bacillus thuringiensis to cf1 cells does not involve activation of adenylate cyclase/pka signaling pathway. | bacillus thuringiensis (bt) bacteria produce cry toxins that are able to kill insect pests. different models explaining the mode of action of these toxins have been proposed. the pore formation model proposes that the toxin creates pores in the membrane of the larval midgut cells after interaction with different receptors such as cadherin, aminopeptidase n and alkaline phosphatase and that this pore formation activity is responsible for the toxicity of these proteins. the alternative model propo ... | 2017 | 27867074 |
| biosterilant effects of bacillus thuringiensis kurstaki hd-73 extract on male wistar albino rats. | chemosterilants have long been used in sterilization programs for managing pet, stray, and wild animals but adverse effects such as trauma, incomplete responses to treatment, and complete abolition of gonadal sources of testosterone often occurs. this study describes the biosterilant effects of administering three doses of bacillus thuringiensis kurstaki hd-73 (bt 5, 50, and 250 mg/kg; 20 rats/dose) extract in adult male wistar albino rats on testicular parameters, function, histology, and a num ... | 2017 | 27865415 |
| glycan region of gpi anchored-protein is required for cytocidal oligomerization of an anticancer parasporin-2, cry46aa1 protein, from bacillus thuringiensis strain a1547. | parasporin-2 (ps2), alternatively named cry46aa1, an anticancer protein derived from bacillus thuringiensis strain a1547, causes specific cell damage via ps2 oligomerization in the cell membrane. although ps2 requires glycosylphosphatidylinositol (gpi)-anchored proteins for its cytocidal action, their precise role is unknown. here, we report that the glycan of gpi induces ps2 oligomerization, which causes cell death. cytotoxicity, cell-binding and oligomerization of the toxin were not observed i ... | 2017 | 27863961 |
| an entomopathogenic bacterium strain, bacillus thuringiensis, as a biological control agent against the red palm weevil, rhynchophorus ferrugineus (coleoptera: curculionidae). | the red palm weevil (rpw), rhynchophorus ferrugineus, is an invasive wood-boring insect that damages palms and sugarcane. bacillus thuringiensis (bt) is an entomopathogenic bacterium which has been modified into various strains and widely used in pest management. the aim of this study was to evaluate the susceptibility of rpw to the ha strain of bt. | 2016 | 27862867 |
| possibly similar genetic basis of resistance to bacillus thuringiensis cry1ab protein in 3 resistant colonies of the sugarcane borer collected from louisiana, usa. | the sugarcane borer, diatraea saccharalis (f.), is a major maize borer pest and a target of transgenic maize expressing bacillus thuringiensis (bt) proteins in south america and the mid-southern region of the united states. evolution of resistance in target pest populations is a great threat to the long-term efficacy of bt crops. in this study, we compared the genetic basis of resistance to cry1ab protein in 3 resistant colonies of sugarcane borer established from field populations in louisiana, ... | 2016 | 27860288 |
| ultrasensitive sers detection of bacillus thuringiensis special gene based on au@ag nrs and magnetic beads. | highly sensitive and selective detection of specific dna sequences is of great importance in clinical diagnosis, environmental and food monitoring, but it still remains challenges to develop a facile method for real sample detection in aqueous solution. here, a simple and recyclable surface enhanced raman scattering (sers) sensor was constructed for bacillus thuringiensis (bt) special gene fragment detection by fe3o4 magnetic beads (mbs) and au-ag core-shell nanorods (au@ag nrs). a hairpin dna w ... | 2017 | 27839730 |
| establishment of a sensitive time-resolved fluoroimmunoassay for detection of bacillus thuringiensis cry1ie toxin based nanobody from a phage display library. | cry1ie toxin was an insect-resistant protein used in genetically modified crops (gmc). in this study, a large human vh gene nanobodies phage displayed library was employed to select anti-cry1ie toxin antibody by affinity panning. after 5 rounds of panning, total 12 positive monoclonal phage particles were obtained. one of the identified positive phage nanobody was expressed in e.coli bl21 and the purified protein was indicated as a molecular mass of approximately 20 kda by sodium dodecyl sulfate ... | 2017 | 27838242 |
| comparison of chito-oligosaccharide production from three different colloidal chitosans using the endochitonsanolytic system of bacillus thuringiensis. | bacillus thuringiensis is a nonhuman pathogen bacterium that is used as a fungal and insect biocontrol agent. because of its environmental interaction, it possesses several extracellular enzymes that are able to degrade chitin and chitosan, two of the most important polymers because of their application in numerous fields. however, in recent years, it has been observed that oligosaccharides from the enzymatic degradation of chitosan have important benefits for human health. comparison and explor ... | 2017 | 27830993 |
| rnai in the striped stem borer, chilo suppressalis, establishes a functional role for aminopeptidase n in cry1ab intoxication. | the striped stem borer, chilo suppressalis, is a major target pest of transgenic rice expressing the cry1ab protein from the bacterium bacillus thuringiensis (bt) in china. evolution of resistance in this pest is a major threat to the durability of bt rice. since bt exerts its activity through binding to specific receptors in the midgut of target insects, identification of functional cry1ab receptors in the midgut of c. suppressalis larvae is crucial to evaluate potential resistance mechanisms a ... | 2017 | 27823898 |
| functional characterization of bacillus thuringiensis cry toxin receptors explains resistance in insects. | bacillus thuringiensis produces cry toxins, which are used as insecticides in sprays and in transgenic crops. however, little is known about the function of cry toxin receptors and the mechanisms that determine their binding specificity and activity. in this study, the crnas of bombyx mori abc transporter c2 (bmabcc2), the toxin-binding region of cadherin-like receptor (btr175-tbr), or aminopeptidase n1 (bmapn1) were injected into xenopus oocytes, and the cry1aa-dependent cation-selective pore f ... | 2016 | 27813251 |
| eco-toxicological risk and impact of pesticides on important parasitoids of cabbage butterflies in cruciferous ecosystem. | eco-toxicological risk and impact of pesticides was estimated on three important parasitoids of butterflies viz., hyposoter ebeninus, cotesia glomerata and pteromalus puparum. four commonly used pesticides were evaluated using standard protocol (of iobc/wprs-group). in laboratory tests, the survival of the female wasps decreased significantly on fresh contact and ingestion of deltamethrin, spinosad and azadirachtin; whereas bacillus thuringiensis var kurstaki (btk) was found harmless pesticide. ... | 2017 | 27810537 |
| comparative genomics of extrachromosomal elements in bacillus thuringiensis subsp. israelensis. | bacillus thuringiensis subsp. israelensis is one of the most important microorganisms used against mosquitoes. it was intensively studied following its discovery and became a model bacterium of the b. thuringiensis species. those studies focused on toxin genes, aggregation-associated conjugation, linear genome phages, etc. recent announcements of genomic sequences of different strains have not been explicitly related to the biological properties studied. we report data on plasmid content analysi ... | 2016 | 27810477 |
| immunological mechanisms of synergy between fungus metarhizium robertsii and bacteria bacillus thuringiensis ssp. morrisoni on colorado potato beetle larvae. | the synergistic effect between the entomopathogenic fungus metarhizium robertsii and a sublethal dose of the bacterium bacillus thuringiensis ssp. morrisoni var. tenebrionis was studied in terms of immune defense reactions and detoxification system activity of the colorado potato beetle, leptinotarsa decemlineata, fourth instar larvae. bacterial infection led to more rapid germination of fungal conidia on integuments. we found a significant decrease of cellular immunity parameters, including tot ... | 2017 | 27751890 |
| a selective insecticidal protein from pseudomonas for controlling corn rootworms. | the coleopteran insect western corn rootworm (wcr) (diabrotica virgifera virgifera leconte) is a devastating crop pest in north america and europe. although crop plants that produce bacillus thuringiensis (bt) proteins can limit insect infestation, some insect populations have evolved resistance to bt proteins. here we describe an insecticidal protein, designated ipd072aa, that is isolated from pseudomonas chlororaphis. transgenic corn plants expressing ipd072aa show protection from wcr insect i ... | 2016 | 27708055 |
| prevalence of cry2-type genes in bacillus thuringiensis isolates recovered from diverse habitats in india and isolation of a novel cry2af2 gene toxic to helicoverpa armigera (cotton boll worm). | insecticidal cry and vip genes from bacillus thuringiensis (bt) have been used for control of lepidopteran insects in transgenic crops. however, novel genes are required for gene pyramiding to delay evolution of resistance to the currently deployed genes. two pcr-based techniques were employed for screening of cry2-type genes in 129 bt isolates from diverse habitats in india and 27 known bt strains. cry2ab-type genes were more prevalent than cry2aa- and cry2ac-type genes. correlation between sou ... | 2016 | 27805417 |
| correction: how quorum sensing connects sporulation to necrotrophism in bacillus thuringiensis. | [this corrects the article doi: 10.1371/journal.ppat.1005779.]. | 2016 | 27798684 |
| pyramiding and evaluation of both a foreign bacillus thuringiensis and a lysine-rich protein gene in the elite indica rice 9311. | gene pyramiding is an efficient approach for the genetic improvement of multiple agronomic traits simultaneously. in this study, we pyramided two foreign genes, cry1ac driven by the rice actin i promoter, and lysine-rich protein (lrp), driven by the endosperm-specific glutelin1 (gt1) promoter, into the elite indica cultivar 9311. these two genes were chosen in an attempt to enhance insect-resistance and lysine (lys) content. in the pyramided line, the foreign gene cry1ac was efficiently expresse ... | 2016 | 27795684 |
| perturbation and delayed recovery of the reed invertebrate assemblage in camargue marshes sprayed with bacillus thuringiensis israelensis. | bacillus thuringiensis var. israelensis (bti) is the most commonly used larvicide to control mosquitoes worldwide. considered as nontoxic to most organisms, bti can nevertheless cause trophic perturbations to natural communities by reducing the abundance of chironomidae, which are a key element of wetland food webs. since august 2006, up to 8400 of the 33 000 ha of mosquito larval biotopes in the camargue (rhône delta, in southern france), are monitored by a public agency and bti-sprayed (aqueou ... | 2016 | 27794203 |
| detection of the cryptic prophage-like molecule pbtic235 in bacillus thuringiensis subsp. israelensis. | bacillus thuringiensis has long been recognized to carry numerous extrachromosomal molecules. of particular interest are the strains belonging to the b. thuringiensis subsp. israelensis lineage, as they can harbor at least seven extrachromosomal molecules. one of these elements seems to be a cryptic molecule that may have been disregarded in strains considered plasmid-less. therefore, this work focused on this cryptic molecule, named pbtic235. using different approaches that included transpositi ... | 2016 | 27793675 |
| unshared binding sites for bacillus thuringiensis cry3aa and cry3ca proteins in the weevil cylas puncticollis (brentidae). | bacillus thuringiensis cry3aa and cry3ca proteins have been reported to be toxic against the african sweetpotato pest cylas puncticollis. in the present work, the binding sites of these proteins in c. puncticollis brush border vesicles suggest the occurrence of different binding sites, but only one of them is shared. our results suggest that pest resistance mediated by alteration of the shared cry-receptor binding site might not render both cry proteins ineffective. | 2016 | 27662801 |
| frequency of cry1f resistance alleles in spodoptera frugiperda (lepidoptera: noctuidae) in brazil. | the frequency of resistance alleles is a major factor influencing the rate of resistance evolution. here, we adapted the f2 screen procedure for spodoptera frugiperda (j. e. smith) with a discriminating concentration assay, and extended associated statistical methods to estimate the frequency of resistance to cry1f protein in s. frugiperda in brazil when resistance was not rare. | 2016 | 26990201 |
| fate of insecticidal bacillus thuringiensis cry protein in soil: differences between purified toxin and biopesticide formulation. | bacillus thuringiensis produces insecticidal proteins known as cry, and its efficiency and absence of side effects make it the most widely used biopesticide. there is little information on the role of soils in the fate of cry proteins from commercial biopesticide formulations, unlike toxins from genetically modified crops, which have been intensively studied in recent years. the persistence of cry in soil was followed under field and laboratory conditions. | 2016 | 26910634 |
| toxin stability improvement and toxicity increase against dipteran and lepidopteran larvae of bacillus thuringiensis crystal protein cry2aa. | bacillus thuringiensis δ-endotoxins are the most widely used biopesticides for controlling economically important crop pests and disease vectors. improving their efficacy is of great benefit. here, an improvement in cry2aa δ-endotoxin toxicity was attempted via a cry gene over expression system using p20 from b. thuringiensis israelensis. | 2016 | 26910489 |
| improved catalytic and antifungal activities of bacillus thuringiensis cells with surface display of chi9602δsp. | the cell-surface display of chitinase chi9602δsp was constructed on bacillus thuringiensis bmb171 by using two repeat n-terminal regions of autolysin (mbgn)2 as the anchoring motif. this study aimed to prepare a chitinolytic whole-cell b. thuringiensis biocatalyst with improved catalytic and antifungal activities. | 2017 | 27782360 |
| genetic hitchhiking and resistance evolution to transgenic bt toxins: insights from the african stalk borer busseola fusca (noctuidae). | since transgenic crops expressing bacillus thuringiensis (bt) toxins were first released, resistance evolution leading to failure in control of pests populations has been observed in a number of species. field resistance of the moth busseola fusca was acknowledged 8 years after bt maize was introduced in south africa. since then, field resistance of this corn borer has been observed at several locations, raising questions about the nature, distribution and dynamics of the resistance trait. using ... | 2017 | 27782120 |
| insecticidal activity and histopathological effects of vip3aa protein from bacillus thuringiensis on spodoptera litura. | vegetative insecticidal proteins (vips) are insecticidal proteins synthesized by bacillus thuringiensis during the vegetative stage of growth. in this study, vip3aa protein, obtained by in vitro expression of the vip3aa gene from b. thuringiensis wb5, displayed high insecticidal activity against spodoptera litura aside from spodoptera exigua and helicoverpa armigera. bioassay results showed that the toxicity of vip3aa protein against s. litura larvae statistically decreased along with the increa ... | 2016 | 27435544 |
| parasporins 1 and 2: their structure and activity. | parasporins are novel protein toxins preferentially cytotoxic against human cancer cells. they are obtained from parasporal inclusions of bacillus thuringiensis and, accordingly, are considered congeners of the insecticidal cry toxins. two types of parasporins have been identified: the three-domain cry toxin type and the β-pore-forming-toxin (β-pft) type. crystal structures of representative members of the two types, ps1aa1 and ps2aa1, have been determined and compared with those of well-studied ... | 2017 | 27769815 |
| insecticidal spectrum and mode of action of the bacillus thuringiensis vip3ca insecticidal protein. | the vip3ca protein, discovered in a screening of spanish collections of bacillus thuringiensis, was known to be toxic to chrysodeixis chalcites, mamestra brassicae and trichoplusia ni. in the present study, its activity has been tested with additional insect species and we found that cydia pomonella is moderately susceptible to this protein. vip3ca (of approximately 90kda) was processed to an approximately 70kda protein when incubated with midgut juice in all tested species. the kinetics of prot ... | 2017 | 27756652 |
| effect of genetically modified corn on the jejunal mucosa of adult male albino rat. | genetically modified (gm) plants expressing insecticidal traits offer a new strategy for crop protection. gm-corn contains bacillus thuringiensis (bt) genes producing delta endotoxins in the whole plant. diet can influence the characteristics of the gastrointestinal tract altering its function and structure. the aim of this study was to evaluate the effect of gm-corn on the histological structure of jejunal mucosa of adult male albino rat using different histological, immunohistochemical and mor ... | 2016 | 27769625 |
| complete genome sequence of bacillus thuringiensis serovar alesti bgsc 4c1, a typical strain with toxicity to lepidoptera insects. | bacillus thuringiensis serovar alesti was used to control caterpillars from 1970s. here we reported the complete genome of bgsc 4c1, the type strain of this serovar. it has a circular chromosome and six plasmids. the largest plasmid pbmb267 contains five insecticidal crystal protein genes (two copies of cry1ae, cry1gb, cry2ab, and a novel cry1m-type gene) and three vegetative insecticidal protein genes (a novel binary toxin gene operon vip1-vip2 and vip3aa). besides, the strain also has many gen ... | 2016 | 27693093 |
| isolation and characterization of gut bacterial proteases involved in inducing pathogenicity of bacillus thuringiensis toxin in cotton bollworm, helicoverpa armigera. | bacillus thuringiensis toxin proteins are deployed in transgenic plants for pest management. the present studies were aimed at characterization of gut bacterial proteases involved in activation of inactive cry1ac protoxin (pro-cry1ac) to active toxin in helicoverpa armigera. bacterial strains were isolated from h. armigera midgut and screened for their proteolytic activation toward pro-cry1ac. among 12 gut bacterial isolates seven isolates showed proteolytic activity, and proteases from three is ... | 2016 | 27766093 |
| susceptibility of grapholita molesta (busck, 1916) to formulations of bacillus thuringiensis, individual toxins and their mixtures. | the oriental fruit moth, grapholita molesta (lepidoptera: tortricidae), is a major pest of fruit trees worldwide, such as peach and apple. bacillus thuringiensis has been shown to be an efficient alternative to synthetic insecticides in the control of many agricultural pests. the objective of this study was to evaluate the effectiveness of b. thuringiensis individual toxins and their mixtures for the control of g. molesta. bioassays were performed with cry1aa, cry1ac, cry1ca, vip3aa, vip3af and ... | 2016 | 27686262 |
| development of monoclonal antibody-based sensitive elisa for the determination of cry1ie protein in transgenic plant. | cry1ie is a kind of bacillus thuringiensis (bt) toxin protein which has a different action model than the cry1ab and cry1ac protein. the transgenic maize expressing cry1ie might be commercially used in the near future and it is urgent to develop a method to detect cry1ie protein in transgenic plants and their products. to develop an elisa method, cry1ie protein was expressed in escherichia coli strain transetta de3, purified with the ni-nta spin columns, and then validated by sequencing. bioassa ... | 2016 | 27659816 |
| development of bt rice and bt maize in china and their efficacy in target pest control. | rice and maize are important cereal crops that serve as staple foods, feed, and industrial material in china. multiple factors constrain the production of both crops, among which insect pests are an important one. lepidopteran pests cause enormous yield losses for the crops annually. in order to control these pests, china plays an active role in development and application of genetic engineering (ge) to crops, and dozens of ge rice and ge maize lines expressing insecticidal proteins from the soi ... | 2016 | 27763554 |
| controlled-release of bacillus thurigiensis formulations encapsulated in light-resistant colloidosomal microcapsules for the management of lepidopteran pests of brassica crops. | bacillus thuringiensis (b. t.) based formulations have been widely used to control lepidopteran pests in agriculture and forestry. one of their weaknesses is their short residual activity when sprayed in the field. using pickering emulsions, mixtures of spores and crystals from three b. t. serovars were successfully encapsulated in colloïdosomal microparticles (50 μm) using innocuous chemicals (acrylic particles, sunflower oil, iron oxide nanoparticles, ethanol and water). a ph trigger mechanism ... | 2016 | 27761325 |
| how well will stacked transgenic pest/herbicide resistances delay pests from evolving resistance? | resistance has evolved to single transgenic traits engineered into crops for arthropod and herbicide resistances, and can be expected to evolve to the more recently introduced pathogen resistances. combining transgenes against the same target pest is being promoted as the solution to the problem. this solution will work if used pre-emptively, but where resistance has evolved to one member of a stack, resistance should easily evolve for the second gene in most cases. we propose and elaborate crit ... | 2017 | 27598030 |
| complete genome sequence of bacillus phage belinda from grand cayman island. | soil from george town, grand cayman island, yielded the bacteriophage belinda, isolated on bacillus thuringiensis dsm 350. we present here the analysis of the complete genome sequence of 162,308 bp, with 298 predicted genes. the genome also contains three trna genes. belinda belongs to the c1 cluster of bacillus phages. | 2016 | 27738022 |
| effective dominance of resistance of spodoptera frugiperda to bt maize and cotton varieties: implications for resistance management. | the resistance of fall armyworm (faw), spodoptera frugiperda, has been characterized to some cry and vip3a proteins of bacillus thuringiensis (bt) expressed in transgenic maize in brazil. here we evaluated the effective dominance of resistance based on the survival of neonates from selected bt-resistant, heterozygous, and susceptible (sus) strains of faw on different bt maize and cotton varieties. high survival of strains resistant to the cry1f (hx-r), cry1a.105/cry2ab (vt-r) and cry1a.105/cry2a ... | 2016 | 27721425 |
| no effect of bt-transgenic rice litter on the meiobenthos community in field ditches. | the non-target effect of bacillus thuringiensis (bt) toxins in aquatic ecosystems is crucial to improve the present assessment of bt-transgenic plants, particularly where crops are cultivated near aquatic ecosystems. we conducted decomposition experiments during two growing seasons to determine the effects of bt-transgenic rice litter with and without insecticide application on the meiobenthos communities in a field ditch. | 2016 | 27717164 |
| identification of a bacillus thuringiensis surface-layer-protein with cytotoxic activity against mda-mb-231 breast cancer cells. | in this work we isolated a surface-layer-protein (slp) from a bacillus thuringiensis (bt) strain to evaluate it cytotoxic effects against mda-mb-231 human breast cancer cells. ap11 was selected from a group of bt strains using slp oligonucleotides developed from bacillus conserved regions. ap11 strain was grown in luria bertani (lb) medium until late exponential phase; an 86 kda protein was extracted using 5 m licl and identified by liquid chromatography-tandem mass spectrometry (lc-ms/ms). it c ... | 2016 | 27713207 |
| type of fitness cost influences the rate of evolution of resistance to transgenic bt crops. | the evolution of resistance to pesticides by insect pests is a significant challenge for sustainable agriculture. for transgenic crops expressing bacillus thuringiensis (bt), crystalline (cry) toxins resistance evolution may be delayed by the high-dose/refuge strategy in which a non-toxic refuge is planted to promote the survival of susceptible insects. the high-dose/refuge strategy may interact with fitness costs associated with resistance alleles to further delay resistance. however, while a d ... | 2016 | 27708457 |
| edible safety assessment of genetically modified rice t1c-1 for sprague dawley rats through horizontal gene transfer, allergenicity and intestinal microbiota. | in this study, assessment of the safety of transgenic rice t1c-1 expressing cry1c was carried out by: (1) studying horizontal gene transfer (hgt) in sprague dawley rats fed transgenic rice for 90 d; (2) examining the effect of cry1c protein in vitro on digestibility and allergenicity; and (3) studying the changes of intestinal microbiota in rats fed with transgenic rice t1c-1 in acute and subchronic toxicity tests. sprague dawley rats were fed a diet containing either 60% gm bacillus thuringiens ... | 2016 | 27706188 |
| the response of soybean to nod factors and a bacteriocin. | microbe-to-plant signals can enhance the growth of a wide range of crops. the responses by soybean (glycine max var. 91m01) to 2 signal molecules were investigated: bradyrhizobium japonicum 532c lipo-chitooligosaccharide (nod bj v [c:18, mefuc]) (lco); and bacillus thuringiensis strain neb17 bacteriocin thuricin 17 (th17). the objective was to assess and quantify the response by soybean, in terms of factors that contribute to yield, to the experimental signal molecules in germination experiments ... | 2016 | 27700227 |
| challenges of implementing a large scale larviciding campaign against malaria in rural burkina faso - lessons learned and recommendations derived from the emira project. | recent malaria control and elimination attempts show remarkable success in several parts of sub-saharan africa. vector control via larval source management represents a new and to date underrepresented approach in low income countries to further reduce malaria transmission. although the positive impact of such campaigns on malaria incidence has been researched, there is a lack of data on which prerequisites are needed for implementing such programs on a routine basis on large scale. our objectiv ... | 2016 | 27686125 |
| local mosquito-borne transmission of zika virus - miami-dade and broward counties, florida, june-august 2016. | during the first 6 months of 2016, large outbreaks of zika virus disease caused by local mosquito-borne transmission occurred in puerto rico and other u.s. territories, but local mosquito-borne transmission was not identified in the continental united states (1,2). as of july 22, 2016, the florida department of health had identified 321 zika virus disease cases among florida residents and visitors, all occurring in either travelers from other countries or territories with ongoing zika virus tran ... | 2016 | 27684886 |
| interaction of pseudostellaria heterophylla with quorum sensing and quorum quenching bacteria mediated by root exudates in a consecutive monoculture system. | many plant-pathogenic bacteria are dependent on quorum sensing (qs) to evoke disease. in this study, the population of qs and quorum quenching (qq) bacteria was analyzed in a consecutive monoculture system of pseudostellaria heterophylla. the isolated qs strains were identified as serratia marcescens with swrir-type qs system and exhibited a significant increase over the years of monoculture. only one qq strain was isolated from newly planted soil sample and was identified as bacillus thuringien ... | 2016 | 27666992 |
| effects of bacillus thuringiensis var. israelensis on nonstandard microcrustacean species isolated from field zooplankton communities. | the toxicity of bacillus thuringiensis var. israelensis on zooplanktonic microcrustaceans was evaluated using individuals collected in coastal wetlands where this larvicide has been used for mosquito control over the last decades. we tested five zooplankton species that coexist with mosquito larvae: two copepods (both nauplii and adults of tropocyclops prasinus and acantocyclops americanus), and three cladocerans (ceriodaphnia reticulata, chydorus sphaericus, and daphnia cf. pulex). our experime ... | 2016 | 27640016 |
| individual and combined effects of bacillus thuringiensis and azadirachtin on plodia interpunctella hübner (lepidoptera: pyralidae). | the indianmeal moth, plodia interpunctella hübner (lepidoptera: pyralidae), is a major stored product pest that is found throughout the world. in this study, the effect of oral exposure to bacillus thuringiensis (berliner) subsp. kurstaki (bacillales: bacillaceae) and azadirachtin was evaluated in third instar p. interpunctella under laboratory conditions. the median lethal concentration (lc50) of bt and azadirachtin on third instars was 490 and 241 μg a.i./ml, respectively. the median lethal ti ... | 2016 | 27638953 |
| effects and mechanisms of bacillus thuringiensis crystal toxins for mosquito larvae. | bacillus thuringiensis is a gram-positive aerobic bacterium that produces insecticidal crystalline inclusions during sporulation phases of the mother cell. the virulence factor, known as parasporal crystals, is composed of cry and cyt toxins. most cry toxins display a common 3-domain topology. cry toxins exert intoxication through toxin activation, receptor binding and pore formation in a suitable larval gut environment. the mosquitocidal toxins of bt subsp. israelensis (bti) were found to be hi ... | 2016 | 27628909 |
| occupational hazards and health cost of women cotton pickers in pakistani punjab. | farm workers and female cotton pickers are exposed to residual impacts of pesticide use in cotton production, in addition to dust, ultraviolet radiation, etc. cotton picking causes various health hazards among cotton pickers with varied health cost. a soil bacterium known as bacillus thuringiensis (bt) is incorporated in cotton seed through genetic modification and it has resistance against certain bollworms of cotton. so it is considered that bt cotton fields have less pesticide exposure compar ... | 2016 | 27618928 |
| highly selective and sensitive electrochemical immunoassay of cry1c using nanobody and π-π stacked graphene oxide/thionine assembly. | cry1c is one of the emerging toxin proteins produced by the bacillus thuringiensis in the genetically modified crops for pest control in agriculture; thus, it is vital to measure the cry1c level in crops for the healthy and environmental concerns. current detections of cry1c mainly rely on instrumental analysis such as high-performance liquid chromatography, which are time-consuming and are generally cost-prohibitive. herein, a simple nanobodies (nbs)-based electrochemical immunosensor has been ... | 2016 | 27617345 |
| role of the sulfur to α-carbon thioether bridges in thurincin h. | thurincin h is a small protein produced by bacillus thuringiensis sf361 with gram-positive antimicrobial properties. the toxins produced by b. thuringiensis are widely used in the agriculture as, e.g. natural preservatives in dairy products. the structure of thurincin h possesses four covalent sulfur to [formula: see text]-carbon bonds that involve the cysteine side-chains; these bonds are probably responsible for the shape and stability of the protein and, thereby, for its antimicrobial propert ... | 2016 | 27615507 |
| proteolytic activation of bacillus thuringiensis cry2ab through a belt-and-braces approach. | proteolytic processing of bacillus thuringiensis (bt) crystal toxins by insect midgut proteases plays an essential role in their insecticidal toxicities against target insects. in the present study, proteolysis of bt crystal toxin cry2ab by plutella xylostella l. midgut proteases (pxmj) was evaluated. both trypsin and chymotrypsin were identified involving the proteolytic activation of cry2ab and cleaving cry2ab at arg(139) and leu(144), respectively. three cry2ab mutants (r139a, l144a, and r139 ... | 2016 | 27598769 |
| larvicidal activity of bacillus thuringiensis var. israelensis cry11aa toxin against haemonchus contortus. | effective control of gastrointestinal parasites is necessary in sheep production. the development of anthelmintics resistance is causing the available chemically based anthelmintics to become less effective. biological control strategies present an alternative to this problem. in the current study, we tested the larvicidal effects of bacillus thuringiensis var. israelensis cry11aa toxin against haemonchus contortus larvae. bacterial suspensions [2 × 108 colony-forming units (cfu) g-1 of the fece ... | 2016 | 27573677 |
| rapid thermostabilization of bacillus thuringiensis serovar konkukian 97-27 dehydroshikimate dehydratase through a structure-based enzyme design and whole cell activity assay. | thermostabilization of an enzyme with complete retention of catalytic efficiency was demonstrated on recombinant 3-dehydroshikimate dehydratase (dhsase or wtasbf) from bacillus thuringiensis serovar konkukian 97-27 (hereafter, b. thuringiensis 97-27). the wtasbf is relatively unstable at 37 °c, in vitro (t1/2(37) = 15 min), in the absence of divalent metal. we adopted a structure-based design to identify stabilizing mutations and created a combinatorial library based upon predicted mutations at ... | 2017 | 27548779 |
| complete genome sequence of bacillus thuringiensis bacteriophage smudge. | smudge, a bacteriophage enriched from soil using bacillus thuringiensis dsm-350 as the host, had its complete genome sequenced. smudge is a myovirus with a genome consisting of 292 genes and was identified as belonging to the c1 cluster of bacillus phages. | 2016 | 27540049 |
| bacterial cross-contamination potential associated with contaminated currency. | previous studies have shown a significant amount of contaminants on paper currencies. it is important to study the transfer of microorganisms between paper currencies to determine whether it meets the level of a human health threat. this cross-contamination potential was analyzed by seeding new us 1-dollar bills with bacillus thuringiensis, and pressing or rubbing them against clean currency to determine the amount of bacteria transfer to the unseeded currency. the transferred amount of bacteria ... | 2016 | 27539663 |
| nematicidal spore-forming bacilli share similar virulence factors and mechanisms. | in the soil environment, bacilli can affect nematode development, fecundity and survival. however, although many bacillus species can kill nematodes, the virulence mechanisms bacilli utilize remain unknown. in this study, we collected 120 strains comprising 30 species across the bacillaceae and paenibacillaceae families of the bacillales order and measured their nematicidal activities in vitro. comparison of these strains' nematicidal capacities revealed that nine species, including bacillus thu ... | 2016 | 27539267 |
| towards novel cry toxins with enhanced toxicity/broader: a new chimeric cry4ba / cry1ac toxin. | attempts have been made to express or to merge different cry proteins in order to enhance toxic effects against various insects. cry1a proteins of bacillus thuringiensis form a typical bipyramidal parasporal crystal and their protoxins contain a highly conserved c-terminal region. a chimerical gene, called cry(4ba-1ac), formed by a fusion of the n-terminus part of cry4ba and the c-terminus part of cry1ac, was constructed. its transformation to an acrystalliferous b. thuringiensis strain showed t ... | 2017 | 27538933 |
| spatio-temporal evolution of sporulation in bacillus thuringiensis biofilm. | bacillus thuringiensis can produce a floating biofilm which includes two parts: a ring and a pellicle. the ring is a thick structure which sticks to the culture container, while the pellicle extends over the whole liquid surface and joins the ring. we have followed over time, from 16 to 96 h, sporulation in the two biofilm parts. sporulation was followed in situ in 48-wells polystyrene microtiterplates with a fluorescence binocular stereomicroscope and a spoiid-yfp transcriptional fusion. sporul ... | 2016 | 27536298 |
| characterization of a highly toxic strain of bacillus thuringiensis serovar kurstaki very similar to the hd-73 strain. | the lbit-1200 strain of bacillus thuringiensis was recently isolated from soil, and showed a 6.4 and 9.5 increase in toxicity, against manduca sexta and trichoplusia ni, respectively, compared to hd-73. however, lbit-1200 was still highly similar to hd-73, including the production of bipyramidal crystals containing only one protein of ∼130 000 kda, its flagellin gene sequence related to the kurstaki serotype, plasmid and reppcr patterns similar to hd-73, no production of β-exotoxin and no presen ... | 2016 | 27535648 |
| interactions between bt crops and aquatic ecosystems: a review. | the term bt crops collectively refers to crops that have been genetically modified to include a gene (or genes) sourced from bacillus thuringiensis (bt) bacteria. these genes confer the ability to produce proteins toxic to certain insect pests. the interaction between bt crops and adjacent aquatic ecosystems has received limited attention in research and risk assessment, despite the fact that some bt crops have been in commercial use for 20 yr. reports of effects on aquatic organisms such as dap ... | 2016 | 27530353 |
| proteomics-based identification of midgut proteins correlated with cry1ac resistance in plutella xylostella (l.). | the diamondback moth, plutella xylostella (l.), is a worldwide pest of cruciferous crops and can rapidly develop resistance to many chemical insecticides. although insecticidal crystal proteins (i.e., cry and cyt toxins) derived from bacillus thuringiensis (bt) have been useful alternatives to chemical insecticides for the control of p. xylostella, resistance to bt in field populations of p. xylostella has already been reported. a better understanding of the resistance mechanisms to bt should be ... | 2016 | 27521921 |
| evaluation of the recovery rate of different swabs for microbial environmental monitoring. | contact plates, dipslides, and swabs are used for the microbiological monitoring of surfaces in controlled environments such as pharmaceutical clean rooms. in the present study, three different swab types using two different methods (direct streaking on agar versus elution followed by membrane filtration) were evaluated. in a first study, representative surfaces in pharmaceutical clean rooms were artificially inoculated using three different environmental strains (in vitro study). in a second st ... | 2017 | 27516491 |
| midgut microbiota and host immunocompetence underlie bacillus thuringiensis killing mechanism. | bacillus thuringiensis is a widely used bacterial entomopathogen producing insecticidal toxins, some of which are expressed in insect-resistant transgenic crops. surprisingly, the killing mechanism of b. thuringiensis remains controversial. in particular, the importance of the septicemia induced by the host midgut microbiota is still debated as a result of the lack of experimental evidence obtained without drastic manipulation of the midgut and its content. here this key issue is addressed by rn ... | 2016 | 27506800 |
| multi stakeholders' attitudes toward bt rice in southwest, iran: application of tpb and multi attribute models. | organisms that have been genetically engineered and modified (gm) are referred to as genetically modified organisms (gmos). bt crops are plants that have been genetically modified to produce certain proteins from the soil bacteria bacillus thuringiensis (bt), which makes these plants resistant to certain lepidopteran and coleopteran species. genetically modified (gm) rice was produced in 2006 by iranian researchers from tarom mowla'ii and has since been called 'bt rice'. as rice is an important ... | 2017 | 27498978 |
| the use of structural modelling to infer structure and function in biocontrol agents. | homology modelling can provide important insights into the structures of proteins when a related protein structure has already been solved. however, for many proteins, including a number of invertebrate-active toxins and accessory proteins, no such templates exist. in these cases, techniques of ab initio, template-independent modelling can be employed to generate models that may give insight into structure and function. in this overview, examples of both the problems and the potential benefits o ... | 2017 | 27498218 |
| effects of field history on corn root injury and adult abundance of northern and western corn rootworm (coleoptera: chrysomelidae). | western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), and northern corn rootworm, diabrotica barberi smith & lawrence, are major pests of corn (zea mays l.). corn producing bacillus thuringiensis (bt) toxins are widely used to manage diabrotica spp.; however, bt resistance by d. v. virgifera has led to high levels of feeding injury in the field. we tested whether field history affected root injury and abundance of adult diabrotica spp. in 2013 and 2014, four ... | 2016 | 27498115 |
| one-pot biogenic fabrication of silver nanocrystals using quisqualis indica: effectiveness on malaria and zika virus mosquito vectors, and impact on non-target aquatic organisms. | currently, mosquito vector control is facing a number of key challenges, including the rapid development of resistance to synthetic pesticides and the recent spread of aggressive arbovirus outbreaks. the biosynthesis of silver nanoparticles (agnps) is currently considered an environmental friendly alternative to the employ of pyrethroids, carbamates and microbial agents (e.g. bacillus thuringiensis var. israelensis), since agnps are easy to produce, effective and stable in the aquatic environmen ... | 2016 | 27491031 |
| how quorum sensing connects sporulation to necrotrophism in bacillus thuringiensis. | bacteria use quorum sensing to coordinate adaptation properties, cell fate or commitment to sporulation. the infectious cycle of bacillus thuringiensis in the insect host is a powerful model to investigate the role of quorum sensing in natural conditions. it is tuned by communication systems regulators belonging to the rnpp family and directly regulated by re-internalized signaling peptides. one such rnpp regulator, nprr, acts in the presence of its cognate signaling peptide nprx as a transcript ... | 2016 | 27483473 |
| safety considerations derived from cry34ab1/cry35ab1 structure and function. | insecticidal proteins developed for in-plant protection against crop pests undergo extensive safety testing during the product development process. safety considerations for insecticidal proteins expressed in crops follow recommended, science-based guidelines and specific studies are conducted on a case by case basis. corn events expressing bacillus thuringiensis (bt) cry34ab1 and cry35ab1 were developed to protect maize from diabrotica virgifera virgifera (western corn rootworm) feeding damage. ... | 2017 | 27480405 |