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microbial dynamics and diversity of bacillus thuringiensis in textile effluent polluted and non-polluted rice field soils of orissa, india.microbial diversity was assessed in the soils of non-polluted rice fields of central rice research institute and choudwar, and textile effluent contaminated (about 30 years) rice fields of choudwar about 4 years after cessation of pollution. the soils contained 0.62-1.01 % organic c and 0.07-0.12 % total n, and measured 6.18-8.24 ph and 0.6-2.68 ms/cm eh which were more in the polluted choudwar soil. the microbial populations (×10(6) cfu/g soil) in the soils were: heterotrophs 1.21-10.9, spore f ...201324426074
optimization of bioinsecticides overproduction by bacillus thuringiensis subsp. kurstaki using linear regression.a multiple linear regression analyses were performed to screen for the significant factors simultaneously influencing production of deltaendotoxin, proteolytic activities and spore formation by a bacillus thuringiensis kurstaki strain. investigated factors included: ph of the medium, available oxygen and inoculum size. it was observed that oxygen availability was the most influencing setting on both deltaendotoxins production and spores counts, followed by initial ph of the medium and inoculum s ...201324459834
dominant resistance to bt cotton and minor cross-resistance to bt toxin cry2ab in cotton bollworm from china.evolution of resistance by insect pests threatens the long-term benefits of transgenic crops that produce insecticidal proteins from bacillus thuringiensis (bt). previous work has detected increases in the frequency of resistance to bt toxin cry1ac in populations of cotton bollworm, helicoverpa armigera, from northern china where bt cotton producing cry1ac has been grown extensively for more than a decade. confirming that trend, we report evidence from 2011 showing that the percentage of individ ...201324478804
effect of midgut proteolytic activity on susceptibility of lepidopteran larvae to bacillus thuringiensis subsp. kurstaki.bacillus thuringiensis (bt) is the most effective microbial control agent for controlling numerous species from different insect orders. all subspecies and strains of b. thuringiensis can produce a spore and a crystalline parasporal body. this crystal which contains proteinaceous protoxins is dissolved in the alkaline midgut, the resulting molecule is then cleaved and activated by proteolytic enzymes and acts as a toxin. an interesting aspect of this activation process is that variations in midg ...201324474937
evaluation of tolerance to bacillus thuringiensis toxins among laboratory-reared western bean cutworm (lepidoptera: noctuidae).the western bean cutworm, striacosta albicosta (smith) (lepidoptera: noctuidae), is a destructive insect pest of dry beans and corn within its native range of western nebraska and eastern colorado. however, since the initiation of an eastward range expansion of s. albicosta in the late 1990s, economic damage has been observed in the midwest, and the species has now reached the atlantic coast and quebec. economic damage to corn occurs by larval feeding on ears, which is not controlled by commerci ...201324498749
molecular characterization of bacillus thuringiensis using rep-pcr.the genetic divergence of 65 strains of bacillus thuringiensis (bt) was determined using rep-pcr. based on the repetitive sequences the box primer was the most informative with 26 fragments, followed by eric (19) and rep (10), generating a total of 55 fragments. the dendogram shows that ten groups were formed when 45% was the average distance of the population: group 1 with 41,5% of the isolates, 33,8% of the isolates were distributed in other groups and 24,6% did not formed distinct group. 53,2 ...201324363981
cloning and analysis of a large plasmid pbmb165 from bacillus thuringiensis revealed a novel plasmid organization.in this study, we report a rapid cloning strategy for large native plasmids via a contig linkage map by bac libraries. using this method, we cloned a large plasmid pbmb165 from bacillus thuringiensis serovar tenebrionis strain ybt-1765. complete sequencing showed that pbmb165 is 77,627 bp long with a gc-content of 35.36%, and contains 103 open reading frames (orfs). sequence analysis and comparison reveals that pbmb165 represents a novel plasmid organization: it mainly consists of a pxo2-like re ...201324312580
purification, biochemical characterization and self-assembled structure of a fengycin-like antifungal peptide from bacillus thuringiensis strain sm1.an antifungal lipopeptide fengycin, producing strain sm1 was isolated from farm land soil sample and identified as bacillus thuringiensis strain sm1 by using 16s rdna analysis. fengycin detected in the culture extract was further purified using hplc and showed a molecular mass of 1492.8 da by maldi-tof-ms analysis. purified fengycin was allowed to construct their self-assembled structure onto a hydrophobic surface showing a clear improvement of antibacterial activity. in self-assembly, fengycin ...201324312083
bacillus thuringiensis poisoning related acute transverse myelitis. 201324340786
screening and identification of a bacillus thuringiensis strain s1/4 with large and efficient insecticidal activities.the bacterium bacillus thuringiensis was recognized for its entomopathogenic activities related to cry and cyt proteins forming the δ-endotoxins and some extracellular activities like the vegetative insecticidal proteins (vip) and cry1i. these activities may act specifically against diverse organisms and some of them typically characterize each strain. here, we screened a set of 212 b. thuringiensis strains to search the higher insecticidal activities. these strains had bipyramidal and cubic cry ...201322915162
immunosuppressive properties of a protein (rvpr1) from the venom of the endoparasitic wasp, pimpla hypochondriaca: mechanism of action and potential use for improving biological control strategies.previously, it was determined that the presence of rvpr1 (a recombinant pimpla hypochondriaca venom protein), in the haemocoel of two lepidopteran larvae, significantly increases their susceptibility to the biological control agents (bcas), bacillus thuringiensis (bt) and beauveria bassiana (richards and dani, 2010; richards et al., 2011). the current work examines the mechanism of action of rvpr1 and demonstrates that it binds to the surface of some haemocytes and disrupts the organization of t ...201322698823
cyt toxins produced by bacillus thuringiensis: a protein fold conserved in several pathogenic microorganisms.bacillus thuringiensis bacteria produce different insecticidal proteins known as cry and cyt toxins. among them the cyt toxins represent a special and interesting group of proteins. cyt toxins are able to affect insect midgut cells but also are able to increase the insecticidal damage of certain cry toxins. furthermore, the cyt toxins are able to overcome resistance to cry toxins in mosquitoes. there is an increasing potential for the use of cyt toxins in insect control. however, we still need t ...201322691603
bacillus thuringiensis insecticidal three-domain cry toxins: mode of action, insect resistance and consequences for crop protection.bacillus thuringiensis bacteria are insect pathogens that produce different cry and cyt toxins to kill their hosts. here we review the group of three-domain cry (3d-cry) toxins. expression of these 3d-cry toxins in transgenic crops has contributed to efficient control of insect pests and a reduction in the use of chemical insecticides. the mode of action of 3d-cry toxins involves sequential interactions with several insect midgut proteins that facilitate the formation of an oligomeric structure ...201322540421
effect of sub-lethal doses of bacillus thuringiensis subsp. aizawai and deltamethrin with regard to fertility and organ toxicity in pregnant albino rats.products with bacillus thuringiensis (bt) and synthetic insecticides have been widely used against important vectors of human diseases. however, few studies have addressed the application of these substances on the female reproduction apparatus during pregnancy at doses that do not cause clinical symptoms of intoxication. seventy pregnant albino rats were analyzed with regard to fertility and histopathology of the kidneys, liver and lungs as well as the morphology of the neonates. the rats were ...201322436576
a tenebrio molitor gpi-anchored alkaline phosphatase is involved in binding of bacillus thuringiensis cry3aa to brush border membrane vesicles.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 o ...201322743140
[conduct of the oviposition of aedes aegypti (l.) in the presence of macrocyclops albidus (j.) and bacillus thuringiensis var. israelensis under lab conditions].the behaviour of the oviposition of pregnant females of aedes aegypti in the presence of biological agents: macrocyclops albidus (copepoda: cyclopoidea) or bacillus thuringiensis var. israelensis (bti) was evaluated under lab conditions. recipients containing 225 ml of dechlorinated water were placed for oviposition with three variants: water with copepods, water with bti, and water. the average of eggs layed in the recipients with copepods and bti were 1 227.9 and 1 200.8, respectively, a figur ...201323427425
cytotoxicity of the bacillus thuringiensis cry4b toxin is mediated by the cadherin receptor bt-r₃ of anopheles gambiae.we demonstrate for the first time the selective cytotoxicity of bacillus thuringiensis subsp. israelensis cry4b toxin mediated by bt-r₃ using a cell-based system, which employs high five insect cells stably expressing bt-r₃. discovery and validation of bt-r₃ as the cry4b receptor was accomplished using a web-based computational pipeline platform that facilitates high-throughput insecticidal target identification utilizing the anopheles gambiae genome. once the cry4b toxin binds to the bt-r₃ rece ...201323788176
segregation and efficacy of the cry1ia1 gene for control of potato tuberworm in four populations of cultivated potato.the potato (solanum tuberosum l.) cultivar 'spuntag2' contains a single copy of the bacillus thuringiensis (bt) cry1ia1 gene and controls potato tuberworm (phthorimaea operculella zeller, lepidoptera: gelechiidae). two potato cultivars and two breeding lines were crossed with spuntag2 creating four populations used to study cry1ia1 segregation and efficacy. the cry1ia1 gene segregated in each of the four populations with a 1:1 ratio. all progeny that were polymerase chain reaction positive for t ...201323786096
evaluation of corn hybrids expressing cry34ab1/cry35ab1 and cry3bbl against the western corn rootworm (coleoptera: chrysomelidae).studies were conducted across nine u.s. states, over 5 yr, to characterize the efficacy of transgenic corn (zea mays l.) hybrids producing insecticidal proteins derived from bacillus thuringiensis (bt) for control of western corn rootworm, diabrotica virgifera virgifera le conte. hybrids tested had the same genetic background, contained one of two single events (das-59122-7 expressing cry34ab1/cry35ab1 or mon 88017 expressing cry3bb1) or a pyramid consisting of both rootworm-active events (smart ...201323786070
injury and interplant compensation for southwestern corn borer (lepidoptera: crambidae) infestations in field corn.growers that plant bacillus thuringiensis (bt) berliner corn (zea mays l.) hybrids are required to plant non-bt corn for resistance management. refuge in a bag (rib) is an emerging approach for resistance management where, for some hybrids having multiple bt traits for a target species, the refuge is planted as a blend of bt and non-bt corn. studies were conducted to evaluate how southwestern corn borer (diatraea grandiosella dyar), when infested at different densities and growth stages, affecte ...201323786069
bacillus thuringiensis insecticidal crystal proteins affect lifespan and reproductive performance of helicoverpa armigera and spodoptera exigua adults.being delivered as sprays or expressed in plant, bacillus thuringiensis (bt) crystalline proteins (cry toxins) display insecticidal activities against numerous lepidopteran, dipteran, and coleopteran larvae. comparative study of toxicities of bt cry toxins between larvae and adults may afford important new insights into the interactions of the toxins with receptor proteins in host insect, and represent intriguing targets for the control of insect pests. however, the effectiveness of bt cry toxin ...201323786046
potato flour mediated solid-state fermentation for the enhanced production of bacillus thuringiensis-toxin.in this study, we explored the efficacy of raw potato flour (pf) as supplement to the conventional lb medium (lb control, designated as m1) for enhancing the concomitant production of endospores and δ-endotoxin from bacillus thuringiensis subsp. kurstaki by solid-state fermentation (ssf). of different concentrations and combinations of media tested, 10% (w/v) pf supplemented lb medium (m2) was found as the best source for the maximum yield of toxin. after 12 h submerged fermentation (smf) at 37° ...201323773700
cross-generational feeding of bt (bacillus thuringiensis)-maize to zebrafish (danio rerio) showed no adverse effects on the parental or offspring generations.in the present study, zebrafish (danio rerio) were fed casein/gelatin-based diets containing either 19% bt (bacillus thuringiensis)-maize or its parental non-bt (nbt)-maize control for two generations (f0: sixty fish; f1: forty-two to seventy fish per treatment). the study focused on growth and reproductive performance, liver cuzn superoxide dismutase (sod) enzyme activity, gene transcript levels targeting important cellular pathways in the liver and mid-intestine, histomorphological evaluation ...201323768244
phylogenetic distribution of phenotypic traits in bacillus thuringiensis determined by multilocus sequence analysis.diverse isolates from a world-wide collection of bacillus thuringiensis were classified based on phenotypic profiles resulting from six biochemical tests; production of amylase (t), lecithinase (l), urease (u), acid from sucrose (s) and salicin (a), and the hydrolysis of esculin (e). eighty two isolates representing the 15 most common phenotypic profiles were subjected to phylogenetic analysis by multilocus sequence typing; these were found to be distributed among 19 sequence types, 8 of which w ...201323762464
the cry4b toxin of bacillus thuringiensis subsp. israelensis kills permethrin-resistant anopheles gambiae, the principal vector of malaria.resurgence of malaria has been attributed, in part, to the development of resistance by anopheles gambiae, a principal vector of the disease, to various insecticidal compounds such as permethrin. permethrin, a neurotoxicant, is widely used to impregnate mosquito nets. an alternative strategy to control mosquitoes is the use of bacillus thuringiensis subsp. israelensis (bti) because there is no observable resistance in the field to the bacterium. bti kills mosquitoes by targeting cadherin molecul ...201323760000
a cadherin-like protein influences bacillus thuringiensis cry1ab toxicity in the oriental armyworm, mythimna separata.cadherins comprise a family of calcium-dependent cell adhesion proteins that act in cell-cell interactions. cadherin-like proteins (cads) in midguts of some insects act as receptors that bind some of the toxins produced by the bacillus thuringiensis (bt). we cloned a cad gene associated with larval midguts prepared from mythimna separata. the full-length cdna (mscad1, genbank accession no. jf951432) is 5642 bp, with an open reading frame encoding a 1757 amino acid and characteristics typical of ...201323754724
insect resistance to bt crops: lessons from the first billion acres.evolution of resistance in pests can reduce the effectiveness of insecticidal proteins from bacillus thuringiensis (bt) produced by transgenic crops. we analyzed results of 77 studies from five continents reporting field monitoring data for resistance to bt crops, empirical evaluation of factors affecting resistance or both. although most pest populations remained susceptible, reduced efficacy of bt crops caused by field-evolved resistance has been reported now for some populations of 5 of 13 ma ...201323752438
effects of genetically modified t2a-1 rice on the gi health of rats after 90-day supplement.bacillus thuringiensis insecticidal toxin (bt) rice will be commercialized as a main food source. traditional safety assessments on genetically modified products pay little attention on gastrointestinal (gi) health. more data about gi health of bt rice must be provided to dispel public' doubts about the potential effects on human health. we constructed an improved safety assessment animal model using a basic subchronic toxicity experiment, measuring a range of parameters including microflora com ...201323752350
enhanced cry1da production in bacillus thuringiensis by driving expression from the σ(e) -dependent bti promoter.to increase the cry1da production in bacillus thuringiensis by enhancing bti promoter activity and fusion with upstream sequence from cry1ab.201323751196
cross-order and cross-phylum activity of bacillus thuringiensis pesticidal proteins.the increasing number of bacillus thuringiensis proteins with pesticidal activities across orders and phyla raises the question how widespread cross-activities are and if they are of sufficient biological significance to have implications for ecological safety of those proteins in pest control applications. cross-activity is reported for 27 proteins and 69 taxa and is substantiated by reasonable evidence (mortality estimates) in 19 cases involving 45 taxa. cross-activities occur in 13 primary ra ...201323747826
response of larval ephestia kuehniella (lepidoptera: pyralidae) to individual bacillus thuringiensis kurstaki toxins mixed with xenorhabdus nematophila.bacillus thuringiensis kurstaki strain bns3 produces parasporal crystals formed by cry1aa, cry1ac and cry2aa delta-endotoxins. in a previous work, we showed that the latter exhibited individually, a weak insecticidal activity against ephestia kuehniella. in order to improve their toxicities, we studied the combined effect of each delta-endotoxin with x. nematophila cells on e. kuehniella larvae growth. xenorhabdus cells were used in combination with spore crystal mixture of the wild strain bns3, ...201323747825
sequence variation and differential splicing of the midgut cadherin gene in trichoplusia ni.the insect midgut cadherin serves as an important receptor for the cry toxins from bacillus thuringiensis (bt). variation of the cadherin in insect populations provides a genetic potential for development of cadherin-based bt resistance in insect populations. sequence analysis of the cadherin from the cabbage looper, trichoplusia ni, together with cadherins from 18 other lepidopterans showed a similar phylogenetic relationship of the cadherins to the phylogeny of lepidoptera. the midgut cadherin ...201323743444
characterization of bacillus thuringiensis cry1 class proteins in relation to their insecticidal action.thirty nine bt cry1 subgroup protein sequences were retrieved from ncbi and analyzed for physicochemical properties, active site and relationship in relation to their variations in toxicity. cry1 proteins were found to be hydrophilic and stable. sosui server predicted presence of two transmembrane regions in ag and a single transmembrane region from aa to ae. emboss pepwheel tool analysis of the transmembrane regions showed that there were 23 highly conserved residues towards the n terminal whic ...201323740394
the red flour beetle as a model for bacterial oral infections.experimental infection systems are important for studying antagonistic interactions and coevolution between hosts and their pathogens. the red flour beetle tribolium castaneum and the spore-forming bacterial insect pathogen bacillus thuringiensis (bt) are widely used and tractable model organisms. however, they have not been employed yet as an efficient experimental system to study host-pathogen interactions. we used a high throughput oral infection protocol to infect t. castaneum insects with c ...201323737991
optimization of photobioreactor growth conditions for a cyanobacterium expressing mosquitocidal bacillus thuringiensis cry proteins.an anabaena strain (pcc 7120#11) that was genetically engineered to express bacillus thuringiensis subsp. israelensis cry genes has shown good larvicidal activity against anopheles arabiensis, a major vector of malaria in africa. response surface methodology was used to evaluate the relationship between key growth factors and the volumetric productivity of pcc 7120#11 in an indoor, flat-plate photobioreactor. the interaction of input co₂ concentration and airflow rate had a statistically signifi ...201323732832
developmental regulation and antifungal activity of a growth-blocking peptide from the beet armyworm spodoptera exigua.insect cytokine growth-blocking peptides (gbps) are involved in growth regulation and the innate immune response. however, the microbial binding and antimicrobial activities of gbps remain unclear. here, we investigate the developmental role and antifungal activity of a gbp from the beet armyworm spodoptera exigua (segbp). sequence analysis predicted that mature segbp consists of 24 amino acid residues, including 2 cysteine residues. during s. exigua development, segbp is constitutively expresse ...201323732405
molecular characterization of chitinase genes from a local isolate of serratia marcescens and their contribution to the insecticidal activity of bacillus thuringiensis strains.the chitinase b (chib) and c (chic) genes and flanking regions from a local isolate of serratia marcescens were cloned individually and sequenced. results showed that these chib and chic genes have a 96 % maximum similarity with chib and chic from different s. marcescens species (genbank numbers z36295.1 and aj630582.1, respectively). the amplified chib fragment, including some upstream and downstream regions, is 1,689-bp long with an open reading frame of 1,500 bp. the amplified fragment of chi ...201323728785
efficiency and midgut histopathological effect of the newly isolated bacillus thuringiensis ks δ-endotoxins on the emergent pest tuta absoluta.tuta absoluta (povolny, 1994) is a devastating moth to the solanaceae plants. it is a challenging pest to control, especially on tomatoes. in this work, we studied the entomopathogenic activity of the cry-forming δ-endotoxins produced by bacillus thuringiensis strain ks and b. thuringiensis kurstaki reference strain hd1 against t. absoluta. these strains carried the cry2, cry1ab, cry1aa / cry1ac, and cry1i genes, and ks also carried a cry1c gene. the δ-endotoxins of ks were approximately twofold ...201323727813
intermolecular interaction between cry2aa and cyt1aa and its effect on larvicidal activity against culex quinquefasciatus.the cyt1aa protein of bacillus thuringiensis susbp. israelensis elaborates demonstrable toxicity to mosquito larvae, but more importantly, it enhances the larvicidal activity of this species cry proteins (cry11aa, cry4aa, and cry4ba) and delays the phenotypic expression of resistance to these that has evolved in culex quinquefasciatus. it is also known that cyt1aa, which is highly lipophilic, synergizes cry11aa by functioning as a surrogate membrane-bound receptor for the latter protein. little ...201323727800
characterization of three antifungal calcite-forming bacteria, arthrobacter nicotianae knuc2100, bacillus thuringiensis knuc2103, and stenotrophomonas maltophilia knuc2106, derived from the korean islands, dokdo and their application on mortar.crack remediation on the surface of cement mortar using microbiological calcium carbonate (caco3) precipitation (micp) has been investigated as a microbial sealing agent on construction materials. however, micp research has never acknowledged the antifungal properties of calcite-forming bacteria (cfb). since fungal colonization on concrete surfaces can trigger biodeterioration processes, fungi on concrete buildings have to be prevented. therefore, to develop a microbial sealing agent that has an ...201323727794
mega-nano detection of foodborne pathogens and transgenes using molecular beacon and semiconductor quantum dot technologies.signature molecules derived from listeria monocytogenes, bacillus thuringiensis, and salmonella typhimurium were detected directly on food substrates (mega) by coupling molecular beacon technology utilizing fluorescent resonance energy transfer (fret), luminescent nanoscale semiconductor quantum dots, and nanoscale quenchers. we designed target dna sequences for detecting hlya, bt cry1ac, and inva genes from l. monocytogenes, b. thuringiensis and salmonella typhimurium, respectively, and prepare ...201323722479
use of a pooled clone method to isolate a novel bacillus thuringiensis cry2a toxin with activity against ostrinia furnacalis.a pooled clone method was developed to screen for cry2a genes. this metagenomic method avoids the need to analyse isolated bacillus thuringiensis strains by performing gene specific pcr on plasmid-enriched dna prepared from a pooled soil sample. using this approach the novel holotype gene cry2ah1 was cloned and characterized. the toxin gene was over-expressed in escherichia coli rosetta (de3) and the expressed toxin accumulated in both the soluble and insoluble fractions. the soluble cry2ah1 was ...201323711413
sustainable control of mosquito larvae in the field by the combined actions of the biological insecticide bti and natural competitors.integrated management of mosquitoes is becoming increasingly important, particularly in relation to avoiding recolonization of ponds after larvicide treatment. we conducted for the first time field experiments that involved exposing natural populations of the mosquito species culex pipiens to: a) application of the biological insecticide bacillus thuringiensis israelensis (bti), b) the introduction of natural competitors (a crustacean community composed mainly of daphnia spp.), or c) a combined ...201323701611
digestive enzyme as benchmark for insecticide resistance development in culex pipiens larvae to chemical and bacteriologic insecticides.this work monitored changes in some digestive enzymes (trypsin and aminopeptidase) associated with the building up of resistance in cx. pipiens larvae to two chemical insecticides (methomyl and/or malathion) and one biological insecticide (bacillus thuringiensis-h14 or b.t h 14). the lc50 value of methomyl for both field- and the 12th generation (f12) of the selected strain was 1.789 ppm and 8.925 ppm respectively. the lc50 value of malathion for both field and the f12 of the selected strain was ...201323697030
differential role of manduca sexta aminopeptidase-n and alkaline phosphatase in the mode of action of cry1aa, cry1ab, and cry1ac toxins from bacillus thuringiensis.aminopeptidase-n (apn1) and alkaline phosphatase (alp) proteins located in the midgut epithelium of manduca sexta have been implicated as receptors for cry1aa, cry1ab, and cry1ac insecticidal proteins produced by bacillus thuringiensis subsp. kurstaki. in this study, we analyzed the roles of alp and apn1 in the toxicity of these three cry1a proteins. ligand blot analysis using brush border membrane vesicles of m. sexta showed that cry1aa and cry1ab bind preferentially to alp during early instars ...201323686267
decolorization of dyehouse effluent and biodegradation of congo red by bacillus thuringiensis run1.a dye-decolorizing bacterium was isolated from a soil sample and identified as bacillus thuringiensis using 16s rrna sequencing. the bacterium was able to decolorize three different textile dyes, namely, reactive blue 13, reactive red 58, and reactive yellow 42, and a real dyehouse effluent up to 80-95% within 6 h. some non-textile industrially important dyes were also decolorized to different extents. fourier transform infrared spectroscopy and gas chromatography-mass spectrometer analysis of t ...201323676913
high-throughput identification of promoters and screening of highly active promoter-5'-utr dna region with different characteristics from bacillus thuringiensis.in bacteria, both promoters and 5'-untranslated regions (5'-utrs) of mrnas play vital regulatory roles in gene expression. in this study, we identified 1203 active promoter candidates in bacillus thuringiensis through analysis of the genome-wide tsss based on the transcriptome data. there were 11 types of σ-factor and 34 types of transcription factor binding sites found in 723 and 1097 active promoter candidates, respectively. moreover, within the 1203 transcriptional units (tus), most (52%) of ...201323675447
bacillus thuringiensis cry4ba toxin employs two receptor-binding loops for synergistic interactions with cyt2aa2.we previously demonstrated that co-expression in escherichia coli of bacillus thuringiensis (bt) subsp. israelensis cry4ba and bt subsp. darmstadiensis cyt2aa2 shows high synergistic toxicity against target mosquito larvae. here, further insights into synergistic interactions between these two toxins were revealed through bioactivity restoration of particular inactive cry4ba-mutant toxins altered within the receptor-binding domain. specific mutations at β2-β3 (y332a) or β4-β5 (f364a) loops, but ...201323665023
[crystal formation peculiarities in pigmented cultures of bacillus thuringiensis].a direct correlation has been established between pink-colored pigmentation and the production of insecticide crystals (toxins) for some bacillus thuringiensis (bt) pigmented cultures. this regularity was for the first time determined by us for bt strains ofthe h3, h10, and h16 serotype. pigment-free clones of these serotypes do not produce crystals. a correlation was not observed in the case of h14 serotype strains with oval inclusions. the revealed correlation makes it possible to distinguish ...201323662449
aphicidal efficacy of scorpion- and spider-derived neurotoxins.insect-specific neurotoxins that act within the insect hemocoel (body cavity) represent an untapped resource for insect pest management. on the basis of recent advances made in development of appropriate delivery systems for transport of these toxins from the insect gut, across the gut epithelium to their target site, we screened neurotoxins derived from scorpion or spider venom for efficacy against the pea aphid, acyrthosiphon pisum, and the green peach aphid, myzus persicae. toxins were select ...201323651761
sodium solute symporter and cadherin proteins act as bacillus thuringiensis cry3ba toxin functional receptors in tribolium castaneum.understanding how bacillus thuringiensis (bt) toxins interact with proteins in the midgut of susceptible coleopteran insects is crucial to fully explain the molecular bases of bt specificity and insecticidal action. in this work, aminopeptidase n (tcapn-i), e-cadherin (tccad1), and sodium solute symporter (tcsss) have been identified by ligand blot as putative cry3ba toxin-binding proteins in tribolium castaneum (tc) larvae. rna interference knockdown of tccad1 or tcsss proteins resulted in decr ...201323645668
existence of lysogenic bacteriophages in bacillus thuringiensis type strains.we screened the existence of bacteriophages in 67 bacillus thuringiensis type strains by phage dna extraction and pcr using phage terminase small subunit (ters)-specific primers to the supernatants and the precipitated pellets of bt cultures, and by transmission electron microscopy. the various bacteriophages were observed from the supernatants of 22 type strains. ten type strains showed the extracted phage dnas and the amplified fragment by ters pcr but 12 type strains showed only the phage dna ...201323632013
two's a crowd: phenotypic adjustments and prophylaxis in anticarsia gemmatalis larvae are triggered by the presence of conspecifics.defence from parasites and pathogens involves a cost. thus, it is expected that organisms use this only at high population densities, where the risk of pathogen transmission may be high, as proposed by the "density-dependent prophylaxis" (ddp) hypothesis. these predictions have been tested in a wide range of insects, both in comparative and experimental studies. we think it pertinent to consider a continuum between solitarious and gregarious living insects, wherein: (1) solitarious insects are t ...201323626700
field evaluation of arbuscular mycorrhizal fungal colonization in bacillus thuringiensis toxin-expressing (bt) and non-bt maize.the cultivation of genetically engineered bacillus thuringiensis toxin-expressing (bt) maize continues to increase worldwide, yet the effects of bt crops on arbuscular mycorrhizal fungi (amf) in soil are poorly understood. in this field experiment, we investigated the impact of seven different genotypes of bt maize and five corresponding non-bt parental cultivars on amf and evaluated plant growth responses at three different physiological time points. plants were harvested 60 days (active growth ...201323624473
microbial degradation of fipronil by bacillus thuringiensis.fipronil, a phenyl pyrazole insecticide has been found to be effective for the control of various insect pests. due to its higher persistence in soil bioremediation is a promising approach to degrade the pesticide from soil. isolation and identification of soil microbes was conducted for bioremediation of fipronil contaminated soils. soil samples collected from different sugarcane growing fields in gurdaspur district with extensive use of pesticide history served as a source of pesticide degradi ...201323618775
quantitative genetic analysis of cry1ab tolerance in ostrinia nubilalis spanish populations.tolerance to bacillus thuringiensis cry1ab toxin in spanish ostrinia nubilalis populations was analyzed by quantitative genetic techniques, using isolines established from field-derived insects. f1 offspring was tested for susceptibility to trypsin activated cry1ab using a concentration that caused a mean larval mortality of 87% (±17% sd). the progeny of the most tolerant isolines (that had shown mortalities lower than 60%) was crossed to obtain the f2 generation that was exposed to the same cry ...201323612057
expression of mosquito-larvicidal toxin genes under the control of a native promoter in enterobacter amnigenus an11.enterobacter amnigenus an11, that can colonize the gut of mosquito larva, is an alternative toxin-producing host to be used as a mosquito control since it is able to float in the feeding zone of mosquito larvae. to produce mosquito-larvicidal toxins in this bacterium, a native promoter has been identified from its genomic dna. the promoter exhibited consensus sequences for -35 and -10 regions of bacterial promoters and constitutively drove the expression of gfp. this promoter was inserted into r ...201323609231
highly efficient enzymatic preparation of c-di-amp using the diadenylate cyclase disa from bacillus thuringiensis.cyclic 3',5'-diadenosine monophosphate (c-di-amp) is a newly recognized bacterial nucleotide second messenger molecule. in addition, it has been shown to be a potential vaccine adjuvant. although multiple methods are available for c-di-amp synthesis, the yields are low and the purification procedures are laborious. here, we report an enzymatic method for more efficient and economical c-di-amp synthesis using a diadenylate cyclase disa from bacillus thuringiensis bmb 171 (btdisa). after overexpre ...201323608499
transcriptional regulation and characteristics of a novel n-acetylmuramoyl-l-alanine amidase gene involved in bacillus thuringiensis mother cell lysis.in bacillus thuringiensis, a novel n-acetylmuramoyl-l-alanine amidase gene (named cwlb) was detected, and the cwlb protein was purified and characterized. reverse transcription-pcr (rt-pcr) results indicated that cwlb and an upstream gene (named cwla) formed one transcriptional unit. 5' rapid amplification of cdna ends (5'-race)-pcr and transcriptional fusions with the lacz gene indicated that transcription of the operon was directed by a promoter, p(cwla), which is located upstream from the cwl ...201323603740
resistance to bt maize in mythimna unipuncta (lepidoptera: noctuidae) is mediated by alteration in cry1ab protein activation.bt maize cultivars based on the event mon810 (expressing cry1ab) have shown high efficacy for controlling corn borers. however, their efficiency for controlling some secondary lepidopteran pests such as mythimna unipuncta has been questioned, raising concerns about potential outbreaks and its economic consequences. we have selected a resistant strain (mr) of m. unipuncta, which is capable of completing its life cycle on bt maize and displays a similar performance when feeding on both bt and non- ...201323603093
tribolium castaneum apolipophorin-iii acts as an immune response protein against bacillus thuringiensis cry3ba toxic activity.in this study, a 2.1-fold apolipophorin-iii mrna up-regulation was found in tribolium castaneum larvae challenged with bacillus thuringiensis cry3ba spore-crystal mixture. knockdown of apolipophorin-iii by rnai resulted in increased t. castaneum larvae susceptibility following cry3ba spore-crystal treatment, demonstrating apolipophorin-iii involvement in insect defense against b. thuringiensis. we showed that apolipophorin-iii participates in t. castaneum immune response to b. thuringiensis acti ...201323602900
iron regulates bacillus thuringiensis haemolysin hlyii gene expression during insect infection.bacillus thuringiensis (bt) is a spore-forming entomopathogen broadly used in agriculture crop. the haemolysin hlyii is an important bt virulence factor responsible for insect death. in this work, we focused on the regulation of the hlyii gene throughout the bacterial growth in vitro and in vivo during insect infection. we show that hlyii regulation depends on the global regulator fur. this regulation occurs independently of hlyiir, the other known regulator of hlyii gene expression. moreover, w ...201323598183
production of the bioinsecticide bacillus thuringiensis subsp. israelensis with deltamethrin increases toxicity towards mosquito larvae.bacillus thuringiensis subsp. israelensis is a bioinsecticide used for larval mosquito control and it represents a safe alternative to chemical insecticides. despite its environmental safety, it is less efficient and persistent than chemical insecticides. to bypass these limitations, we propose to combine the advantages of chemical and biological insecticides by producing bti in a medium supplemented with a chemical insecticide (ddt, deltamethrin, permethrin, propoxur or temephos). among the inv ...201323594143
spaceflight-induced enhancement of 2-keto-l-gulonic acid production by a mixed culture of ketogulonigenium vulgare and bacillus thuringiensis.two bacterial strains used for industrial production of 2-keto-l-gulonic acid (2-klg), ketogulonigenium vulgare 2 and bacillus thuringiensis 1514, were loaded onto the spacecraft shenzhou vii and exposed to space conditions for 68 h in an attempt to increase their fermentation productivities of 2-klg. an optimal combination of mutants b. thuringiensis 320 and k. vulgare 2194 (kb2194-320) was identified by systematically screening the ph and 2-klg production of 16 000 colonies. compared with the ...201323581457
in silico cloning and annotation of genes involved in the digestion, detoxification and rna interference mechanism in the midgut of bactrocera dorsalis [hendel (diptera: tephritidae)].as the second largest organ in insects, the insect midgut is the major tissue involved in the digestion of food and detoxification of xenobiotics, such as insecticides, and the first barrier and target for oral rna interference (rnai). in this study, we performed a midgut-specific transcriptome analysis in the oriental fruit fly, bactrocera dorsalis, an economically important worldwide pest, with many populations showing high levels of insecticide resistance. using high-throughput sequencing, 52 ...201323577657
genetically modified crops: detection strategies and biosafety issues.genetically modified (gm) crops are increasingly gaining acceptance but concurrently consumers' concerns are also increasing. the introduction of bacillus thuringiensis (bt) genes into the plants has raised issues related to its risk assessment and biosafety. the international regulations and the codex guidelines regulate the biosafety requirements of the gm crops. in addition, these bodies synergize and harmonize the ethical issues related to the release and use of gm products. the labeling of ...201323566850
activity of bacillus thuringiensis cyt1ba crystal protein against hymenopteran forest pests.a crystal-spore suspension of ps201t6 was toxic to larvae of diprion similis (hymenoptera: diprionidae). toxicity was at least in part attributable to the cyt1ba crystal protein, as demonstrated by bioassays of solubilized protein produced by escherichia coli expressing ps201t6's cyt1ba gene. ps201t6 reduced survival and growth of d. similis in a 2-week field experiment. in laboratory bioassays, both toxin and parental strain affected acantholyda erythrocephala (pamphiliidae), pikonema alaskensi ...201323545068
bt crops producing cry1ac, cry2ab and cry1f do not harm the green lacewing, chrysoperla rufilabris.the biological control function provided by natural enemies is regarded as a protection goal that should not be harmed by the application of any new pest management tool. plants producing cry proteins from the bacterium, bacillus thuringiensis (bt), have become a major tactic for controlling pest lepidoptera on cotton and maize and risk assessment studies are needed to ensure they do not harm important natural enemies. however, using cry protein susceptible hosts as prey often compromises such s ...201323544126
identification of a bacillus thuringiensis cry8da toxin-binding glucosidase from the adult japanese beetle, popillia japonica.cry8da from bacillus thuringiensis galleriae sds-502 has insecticidal activity against both the larvae and adult japanese beetle (popillia japonica newman). the receptor determines the specificity of the insecticidal activity of cry proteins and hence, in order to reveal the mode of action of cry toxin, receptor identification is a necessary step. however, a receptor for cry8-type toxin has not been identified in the scarabaeidae family of insects. therefore, we aimed to identify the receptor of ...201323541518
cloning and characterization of a novel cry8ab1 gene from bacillus thuringiensis strain b-jjx with specific toxicity to scarabaeid (coleoptera: scarabaeidae) larvae.isolation of bacillus thuringiensis (bt) strain or its cry gene encoding insecticidal crystal protein (icp) with specific toxicity is of great importance to biological control of insect pests. in this study, by screening 66 strains of bt isolated from soil samples collected in shandong province, china, a new cry8-type gene from bt strain b-jjx was identified via pcr-rflp method. this novel gene, cry8ab1, was cloned from the bt strain b-jjx and expressed in an acrystalliferous mutant strain hd-73 ...201323541365
effect of stacked insecticidal cry proteins from maize pollen on nurse bees (apis mellifera carnica) and their gut bacteria.honey bee pollination is a key ecosystem service to nature and agriculture. however, biosafety research on genetically modified crops rarely considers effects on nurse bees from intact colonies, even though they receive and primarily process the largest amount of pollen. the objective of this study was to analyze the response of nurse bees and their gut bacteria to pollen from bt maize expressing three different insecticidal cry proteins (cry1a.105, cry2ab2, and cry3bb1). naturally cry proteins ...201323533634
potential shortfall of pyramided transgenic cotton for insect resistance management.to delay evolution of pest resistance to transgenic crops producing insecticidal proteins from bacillus thuringiensis (bt), the "pyramid" strategy uses plants that produce two or more toxins that kill the same pest. in the united states, this strategy has been adopted widely, with two-toxin bt cotton replacing one-toxin bt cotton. although two-toxin plants are likely to be more durable than one-toxin plants, the extent of this advantage depends on several conditions. one key assumption favoring ...201323530245
bacillus thuringiensis israelensis (bti) for the control of dengue vectors: systematic literature review.to systematically review the literature on the effectiveness of bacillus thuringiensis israelensis (bti), when used as a single agent in the field, for the control of dengue vectors.201323527785
draft genome sequence of bacillus thuringiensis strain dar 81934, which exhibits molluscicidal activity.bacillus thuringiensis has been widely used as a biopesticide for a long time. its molluscicidal activity, however, is rarely realized. here, we report the genome sequence of b. thuringiensis strain dar 81934, a strain with molluscicidal activity against the pest snail cernuella virgata.201323516227
complete genome sequence of bacillus thuringiensis subsp. thuringiensis strain is5056, an isolate highly toxic to trichoplusia ni.the genome sequence of the entomopathogen bacillus thuringiensis subsp. thuringiensis strain is5056 was determined. the chromosome is composed of 5,491,935 bp. in addition, is5056 harbors 14 plasmids ranging from 6,880 to 328,151 bp, four of which contain nine insecticidal protein genes, cry1aa3, cry1ab21, cry1ba1, cry1ia14, cry2aa9, cry2ab1, vip1, vip2, and vip3aa10.201323516221
complete genome sequence of bacillus thuringiensis subsp. kurstaki strain hd73.bacillus thuringiensis is a gram-positive bacterium that produces intracellular protein crystals toxic to a wide variety of insect larvae. we report the complete genome sequence of bacillus thuringiensis subsp. kurstaki strain hd73 from the centre oilb (institut pasteur, france), which belongs to serotype 3ab and is toxic to lepidopteran larvae.201323516207
constructing bacillus thuringiensis strain that co-expresses cry2aa and chitinase.a triple recombineering technique was used with plasmid pht315 to produce phtec, a construct carrying chitinase and cry2aa genes from bacillus thuringiensis subsp. kurstaki 4.0718. transformation of wild-type b. thuringiensis strain hd73 and the acrystalliferous strain cry-b with phtec resulted in the recovery of recombinant strains that expressed cry2aa as cubic crystals in the cell pellet and soluble chitinase protein. the toxicity of hd73 (phtec) against helicoverpa armigera larvae increased ...201323515891
cation-π interactions as lipid-specific anchors for phosphatidylinositol-specific phospholipase c.amphitropic proteins, such as the virulence factor phosphatidylinositol-specific phospholipase c (pi-plc) from bacillus thuringiensis , often depend on lipid-specific recognition of target membranes. however, the recognition mechanisms for zwitterionic lipids, such as phosphatidylcholine, which is enriched in the outer leaflet of eukaryotic cells, are not well understood. a 500 ns long molecular dynamics simulation of pi-plc at the surface of a lipid bilayer revealed a strikingly high number of ...201323506313
efficient genetic transformation of okra (abelmoschus esculentus (l.) moench) and generation of insect-resistant transgenic plants expressing the cry1ac gene.agrobacterium -mediated transformation system for okra using embryos was devised and the transgenic bt plants showed resistance to the target pest, okra shoot, and fruit borer ( earias vittella ). okra is an important vegetable crop and progress in genetic improvement via genetic transformation has been impeded by its recalcitrant nature. in this paper, we describe a procedure using embryo explants for agrobacterium-mediated transformation and tissue culture-based plant regeneration for efficien ...201323504006
enhancement of heavy metal phytoremediation by alnus firma with endophytic bacillus thuringiensis gdb-1.phytoremediation shows potential for remediating mine tailing sites contaminated with heavy metals. our aim was to isolate, characterize, and assess the potential of endophytic bacteria to enhance growth and metal accumulation by the hyperaccumulator alnus firma. a bacterial strain isolated from roots of pinus sylvestris had the capacity to remove heavy metals from mine tailing and was identified as bacillus thuringiensis gdb-1 based on 16s ribosomal dna sequencing. gdb-1 exhibited plant growth- ...201323500429
pest trade-offs in technology: reduced damage by caterpillars in bt cotton benefits aphids.the rapid adoption of genetically engineered (ge) plants that express insecticidal cry proteins derived from bacillus thuringiensis (bt) has raised concerns about their potential impact on non-target organisms. this includes the possibility that non-target herbivores develop into pests. although studies have now reported increased populations of non-target herbivores in bt cotton, the underlying mechanisms are not fully understood. we propose that lack of herbivore-induced secondary metabolites ...201323486438
bacterial chitin binding proteins show differential substrate binding and synergy with chitinases.glycosyl hydrolase (gh) family 18 chitinases (chi) and family 33 chitin binding proteins (cbps) from bacillus thuringiensis serovar kurstaki (btchi and btcbp), b. licheniformis dsm13 (blichi and blicbp) and serratia proteamaculans 568 (spchib and spcbp21) were used to study the efficiency and synergistic action of btchi, blichi and spchib individually with btcbp, blicbp or spcbp21. chitinase assay revealed that only btchi and spchib showed synergism in hydrolysis of chitin, while there was no in ...201323480960
a new enrichment method for isolation of bacillus thuringiensis from diverse sample types.new or more efficient methodologies having different principles are needed, as one method could not be suitable for isolation of organisms from samples of diverse types and from various environments. in present investigation, growth kinetics study revealed a higher germination rate, a higher growth rate, and maximum sporulation of bacillus thuringiensis (bt) compared to other bacillus species. considering these facts, a simple and efficient enrichment method was devised which allowed propagation ...201323468005
probing the fractal pattern and organization of bacillus thuringiensis bacteria colonies growing under different conditions using quantitative spectral light scattering polarimetry.development of methods for quantification of cellular association and patterns in growing bacterial colony is of considerable current interest, not only to help understand multicellular behavior of a bacterial species but also to facilitate detection and identification of a bacterial species in a given space and under a given set of condition(s). we have explored quantitative spectral light scattering polarimetry for probing the morphological and structural changes taking place during colony for ...201323462968
occurrence and larval movement of diatraea saccharalis (lepidoptera: crambidae) in seed mixes of non-bt and bt pyramid corn.larval movement of target pest populations among bt and non-bt plants is a major concern in the use of a seed mixture refuge strategy for bt resistance management. in this study, occurrence and larval movement of the sugarcane borer, diatraea saccharalis (f.), were evaluated in four planting patterns of non-bt and bt plants containing genuity® smartstax(tm) traits in 2009-2011. the four planting patterns were: (1) a pure stand of 27 bt plants; (2) one non-bt plant in the center, surrounded by 26 ...201323456950
expression of cry3a gene and its toxicity against asian gray weevil myllocerus undecimpustulatus undatus marshall (coleoptera: curculionidae).coleopterans are the most damaging pests of many agricultural and forestry crops; there is an urgent need to develop effective biopesticides against these insects. enhancers of bt toxicity typify an opportunity to improve currently available commercial products into more effective control agents against diverse pests. a 1.9 kb dna fragment, pcr amplified from native isolates of bt using cry3a gene specific primers was cloned in expression vector pqe-80l and then used for transformation of escher ...201323456617
characterization of the chitinase gene in bacillus thuringiensis mexican isolates.the chitinase gene was molecularly characterized in five bacillus thuringiensis mexican isolates, mr10, mr11, mr21, mr33, and rn52. the proteins derived from these genes were tested for their chitinase activity using fluorogenic chitin derivatives. in order to verify if chitinase genes were functional, they were cloned, and enzymatic activity of recombinant chitinases was also tested. results indicated that enzymes exhibited endochitinase activity. the highest hydrolytic activity shown against t ...201323456349
characterization of cry9da4, cry9eb2, and cry9ee1 genes from bacillus thuringiensis strain t03b001.three cry9 genes, cry9da4, cry9eb2, and cry9ee1, were cloned from bacillus thuringiensis strain t03b001 using a high-resolution melting analysis method. all three cry9 genes were overexpressed in escherichia coli rosetta (de3), and the expressed products cry9eb2 and cry9ee1 were shown to be toxic to plutella xylostella and ostrinia furnacalis, but not to helicoverpa armigera or colaphellus bowringi. the bioassay of cry9eb2 and cry9ee1 against cry1ac-resistant p. xylostella strains indicated that ...201323455566
risk assessment for helicoverpa zea (lepidoptera: noctuidae) resistance on dual-gene versus single-gene corn.recent environmental protection agency (epa) decisions regarding resistance management in bt-cropping systems have prompted concern in some experts that dual-gene bt-corn (cryla.105 and cry2ab2 toxins) may result in more rapid selection for resistance in helicoverpa zea (boddie) than single-gene bacillus thuringiensis (bt)-corn (crylab toxin). the concern is that bt-toxin longevity could be significantly reduced with recent adoption of a natural refuge for dual-gene bt-cotton (crylac and cry2ab2 ...201323448055
investigating alternatives to traditional insecticides: effectiveness of entomopathogenic fungi and bacillus thuringiensis against citrus thrips and avocado thrips (thysanoptera: thripidae).citrus thrips, scirtothrips citri (moulton) (thysanoptera: thripidae), is a plant-feeding pest most widely recognized for causing damage to citrus (citrus spp. l. [rutaceae]) and mango (mangifera indica l. [anacardiaceae]) fruits. this insect has recently broadened its known host range to become a significant pest of california grown blueberries. avocado thrips, scirtothrips. perseae nakahara (thysanoptera: thripidae), is a recent, invasive pest of california avocados, persea americana mill. (la ...201323448016
the effect of gamma sterilization on the insecticidal toxicity of engineered and conventional bacillus thuringiensis strains.this study evaluates the effect of gamma radiation on the spore activity, toxicity, and crystal structures of two engineered bacillus thuringiensis (bt) strains, tnx and tny, and the reference bt strain hd-1. we attempted to identify dosages of cobalt-60 gamma radiation that would inactivate bt spores but not affect its toxicity. in the radiation dosage range of 10-15 kilogray, no viable spore formation and no significant reduction of the efficiency of bt against lepidopteran larvae were observe ...201323448012
the atp-binding cassette transporter subfamily c member 2 in bombyx mori larvae is a functional receptor for cry toxins from bacillus thuringiensis.bacillus thuringiensis is the most widely used biopesticide, and its cry toxin genes are essential transgenes for the generation of insect-resistant transgenic crops. recent reports have suggested that atp-binding cassette transporter subfamily c2 (abcc2) proteins are implicated in cry intoxication, and that a single amino acid insertion results in high levels of resistance to cry1 toxins. however, there is currently no available direct evidence of functional interactions between abcc2 and cry t ...201323432933
[susceptibility of aedes aegypti (l.) strains from havana to a bacillus thuringiensis var. israelensis].the integration of chemical and biological methods is one of the strategies for the vector control, due to the existing environmental problems and the concerns of the community as a result of the synthetic organic insecticide actions. the bacterium called bacillus thuringiensis var. israelensis in liquid formulation has been widely used in the vector control programs in several countries and has shown high efficacy at lab in cuba.201323424808
[influence of biotic factors on the efficacy of bacillus thuringiensis var. israelensis against aedes aegypti (diptera: culicidae)].bacillus thuringiensis h-14 has shown high efficacy on aedes aegypti larvae. but a number of factors could affect its effectiveness. knowing these factors is of vital importance for improving the application parameters in real conditions in order to guarantee the treatment's efficiency and to reduce environmental impact.201323424800
mosquito autogeny in aedes caspius (diptera: culicidae): alterations of larval nourishments reservation upon bacterial infection.the present study recorded mosquito autogeny for the first time amongst aedes caspius species in the eastern region of saudi arabia. laboratory rearing showed an obligatory autogenous species of ae. caspius since it foregoes blood feeding during its first ovarian cycle, even in the presence of the hosts (cd mouse), but produces its second egg batch only if ingested a blood meal. both morphological and molecular identification confirmed that both autogenous and anautogenous strains belong to the ...201323955943
inheritance of cry1f resistance, cross-resistance and frequency of resistant alleles in spodoptera frugiperda (lepidoptera: noctuidae).transgenic maize, zea maize l., expressing the cry1f protein from bacillus thuringiensis has been registered for spodoptera frugiperda (j. e. smith) control since 2003. unexpected damage to cry1f maize was reported in 2006 in puerto rico and cry1f resistance in s. frugiperda was documented. the inheritance of cry1f resistance was characterized in a s. frugiperda resistant strain originating from puerto rico, which displayed >289-fold resistance to purified cry1f. concentration-response bioassays ...201323941623
midgut aminopeptidase n isoforms from ostrinia nubilalis: activity characterization and differential binding to cry1ab and cry1fa proteins from bacillus thuringiensis.aminopeptidase n (apn) isoforms from lepidoptera are known for their involvement in the mode of action of insecticidal cry proteins from bacillus thuringiensis. these enzymes belong to a protein family with at least eight different members that are expressed simultaneously in the midgut of lepidopteran larvae. here, we focus on the characterization of the apns from ostrinia nubilalis (onapns) to identify potential cry receptors. we expressed onapns in insect cells using a baculovirus system and ...201323933214
comparison between diflubenzuron and a bacillus thuringiensis israelensis- and lysinibacillus sphaericus-based formulation for the control of mosquito larvae in urban catch basins in switzerland.a field test was conducted to evaluate a commercial biolarvicide based on bacillus thuringiensis var. israelensis and lysinibacillus sphaericus to control mosquitoes breeding in catch basins in southern switzerland. the efficacy and residual activity of the microbial mosquito larvicide applied at the recommended rate of 10 g per catch basin was compared to the currently used larvicide diflubenzuron. both products provided a very good control activity (> 97% of reduction) of late instars (3rd and ...201323923328
contrasting patterns of tolerance between chemical and biological insecticides in mosquitoes exposed to uv-a.mosquitoes are vectors of major human diseases, such as malaria, dengue or yellow fever. because no efficient treatments or vaccines are available for most of these diseases, control measures rely mainly on reducing mosquito populations by the use of insecticides. numerous biotic and abiotic factors are known to modulate the efficacy of insecticides used in mosquito control. mosquito breeding sites vary from opened to high vegetation covered areas leading to a large ultraviolet gradient exposure ...201323911355
an improved pcr-restriction fragment length polymorphism (rflp) method for the identification of cry1-type genes.the cry1-type genes of bacillus thuringiensis represent the largest cry gene family, which contains 50 distinct holotypes. it is becoming more and more difficult to identify cry1-type genes using current methods because of the increasing number of cry1-type genes. in the present study, an improved pcr-restriction fragment length polymorphism (pcr-rflp) method which can distinguish 41 holotypes of cry1-type genes was developed. this improved method was used to identify cry1-type genes in 20 b. th ...201323995930
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