High-throughput deep-sequencing technology and bioinformatics analysis of the small RNA(sRNA)population isolated from plants allows universal virus detection and complete virome reconstruction for a given sample.In th...High-throughput deep-sequencing technology and bioinformatics analysis of the small RNA(sRNA)population isolated from plants allows universal virus detection and complete virome reconstruction for a given sample.In the present sRNA deep-sequencing analysis of virus-infected wheat samples in the Czech Republic,samples were firstly tested for barley yellow dwarf viruses(BYDVs),wheat streak mosaic virus(WSMV)and wheat dwarf virus(WDV)using ELISA,RT-PCR and PCR.Subsequent sRNA sequencing of these samples yielded more than^60 million single-end 50-bp reads with high confidence for nine field samples of wheat.Overall,16.5%of reads were virus-specific and 83.5%were mapped to the host.More 21-nt reads(-7.7E+06 reads)were found than 24-nt(~6.20E+06 reads)or 22-nt(-4.30E+06 reads)reads.De novo assembly of the high-quality contigs revealed the presence of three earlier repoted viruses in the Czech Republic:BYDVs(31.48%),WSMV(24.23%)and WDV(2666%).We also showed the presence of cereal yellow dwarf virus(14.33%;two species CYDV-RPS and CYDV-RPV family Luteoviridae/Polerovirus)and wheat yellow dwarf virus(WYDV,3.30%;Luteoviridae).Phylogenetic analysis showed CYDV and WYDV grouped separately from BYDVs.Furthermore,several recombination breakpoints were found among the groups of yellow dwarf viruses(BYDVs,CYDV,and WYDV).Using RNA deep sequencing,we confirmed the presence of the three known viruses(BYDVs,WSMV,and WDV)and the first record of two species of CYDV and WYDV in wheat in the Czech Republic.展开更多
Stone fruits are an important crop in most parts of the world and are heavily challenged by several viruses including Plum pox virus (PPV), Prune dwarf virus (PDV), Prunus necrotic ringspot virus (PNRSV), and Apple ch...Stone fruits are an important crop in most parts of the world and are heavily challenged by several viruses including Plum pox virus (PPV), Prune dwarf virus (PDV), Prunus necrotic ringspot virus (PNRSV), and Apple chlorotic leaf spot virus (ACLSV). We validated the PPV resistance in C5 plum plants (commercially known as HoneySweet) grown in the Czech Republic for more than 16 years in a field trial experiment under natural environmental conditions. We quantified single (PPV-Rec) and mixed viruses (PPV-Rec+ACLSV, PPV-Rec+PDV and PPV-Rec+ACLSV+PDV) in C5 transgenic plums inoculated for the period 2016 to 2018. The accumulation of PPV-Rec was high (~5.43E+05 copies) compared with that of ACLSV (~8.70E+04 copies) in the inoculated graft of C5 transgenic plants. Leaves close to the inoculum sources showed a differential level of virus titre in single and mixed infections (~10 to ~5×10^2 copies). C5 plants with permanent virus pressure showed 103- to 105-fold fewer copies of viruses than those of the inoculated graft. We observed high accumulation of conserved miRNAs such as miR167, miR69 and miR396 in C5 plants co-infected with PPV, ACLSV and PDV that are associated with its resistance against viruses. Overall, i) C5 transgenic plums showed high resistance to PPV infection, and a low level (~32 copies) of PPV only accumulated in some grafted plants, ii) high accumulation of PPV was found in inoculated grafts in single PPV infection and mixed infections, iii) heterologous virus infection sustained by ACLSV or PDV did not suppress PPV resistance, and iv) high and low conserved microRNAs accumulated in C5 plants.展开更多
Objective:To evaluate new compounds synthesized by integrating quinoline,quinazoline,and acridine rings with the active moiety of(5-nitroheteroaryl)methylene hydrazine.Methods:A new series of compounds(1a,1b,2a,2b,3a,...Objective:To evaluate new compounds synthesized by integrating quinoline,quinazoline,and acridine rings with the active moiety of(5-nitroheteroaryl)methylene hydrazine.Methods:A new series of compounds(1a,1b,2a,2b,3a,and 3b)were synthesized and evaluated for cytotoxicity against COS-7 cells using the MTT assay.In vitro anti-plasmodial activity of the compounds was measured against CQ-sensitive(3D7)and CQ-resistant(K1)Plasmodium(P.)falciparum strains.β-hematin assay was performed to assess the inhibitory effects ofβ-hematin formation for new compounds.Results:The synthetic compounds had anti-plasmodial activity against blood-stage of 3D7[IC50=(0.328-5.483)μM]and K1[IC50=(0.622-7.746)μM]strains of P.falciparum,with no cytotoxicity against COS-7 cells in effective doses.Compounds 1a,1b,and 2b were the most effective derivatives against P.falciparum 3D7 and K1 strains.Based on theβ-hematin assay,the inhibition ofβ-hematin formation is the main mechanism of the inhibitory effect of these compounds.Conclusions:The synthetic compounds could inhibit the erythrocytic stages of CQ-sensitive and resistant P.falciparum strains without toxicity towards mammalian cells.Compounds 1b,2a,and 2b had comparable anti-plasmodial activity against both CQ-sensitive(3D7)and resistant(K1)P.falciparum strains.These compounds may be promising lead structures for the development of new anti-malarial drugs.展开更多
Non-invasive therapeutic methods have recently been used in medical sciences. Enzymes have shown high activity at very low concentrations in laboratories and pharmaceutical,enabling them to play crucial roles in diffe...Non-invasive therapeutic methods have recently been used in medical sciences. Enzymes have shown high activity at very low concentrations in laboratories and pharmaceutical,enabling them to play crucial roles in different biological phenomena related to living organism, especially human medicine. Recently, using the therapeutic methods based on non-invasive approaches has been emphasized in medical society. Researchers have focused on producing medicines and tools reducing invasive procedures in medical.Collagenases are proteins which catalyze chemical processes and break the peptide bonds in collagen. Collagen may be generated more than the required amount or produced in unsuitable sites or may not degrade after a certain time. In such cases, using an injectable collagenase or its ointment can be helpful in collagen degradation. In both in vitro and in vivo tests, it has been revealed that collagenases have several therapeutic properties in wound healing, burns, nipple pain and some diseases including intervertebral disc herniation, keloid, cellulite, lipoma among others. This review describes the therapeutic application of collagenase in medical sciences and the process for its production using novel methods, paving the way for more effective and safe applications of collagenases.展开更多
<strong>Background: </strong><span><span><span><span>With the rapid expansion of insecticide resistance limiting the effectiveness of insecticide-based vector control interventions,...<strong>Background: </strong><span><span><span><span>With the rapid expansion of insecticide resistance limiting the effectiveness of insecticide-based vector control interventions, integrated control strategies associating larviciding could be appropriate to improve current control efforts. The present experimental study assesses laboratory and field efficacy of the larvicide </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G</span></span></span></span><span><span><span><span> on <i>Anopheline</i> and <i>Culicine</i> larval stages in Yaoundé. <strong>Methods:</strong> The effect of the larvicide </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G,</span></span></span></span><span><span><span><span> a combination of <i>Bacillus</i><span> <i>thuringiensis</i> var. <i>israelensis</i> </span>(<i>Bti</i>) </span></span></span></span><span><span><span><span>and <i>Bacillus</i> <i>sphaericus</i> (<i>Bs</i>),</span></span></span></span><span><span><span><span> on larval development was assessed during both laboratory and open field trial experiments. Laboratory experiments permitted the evaluation of five different concentrations with four replicates/experiments. Laboratory experiments were conducted with <i>Anopheles</i> <i>coluzzii</i> “Ngousso” and <i>Culex</i> <i>quinquefasciatus</i> laboratory strains. Open field trials were conducted using </span></span></span></span><span><span><span><span>sixteen plastic containers with a diameter of 0.31 m buried in an array of four rows with 4 containers each. Distance between rows and between containers in a row was 1 meter. This experiment permitted to </span></span></span></span><span><span><span><span>test the effect of the microbial larvicide </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G</span></span></span></span><span><span><span><span> under operational application conditions on field mosquito populations. <strong>Results:</strong> <span>The time to induce 100% mortality after exposure to serial concentrations of the larvicide varied according to the dose from 4 - 12 hours for <i>An.</i> <i>coluzzii</i> and 6 - 9 hours for <i>Cx.</i> <i>quinquefasciatus</i> in laboratory experiments. Measurements of the</span> residual activity indicated that all </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G</span></span></span></span><span><span><span><span> concentrations were still active after 35 days and killed 86</span></span></span></span><span><span><span><span>% </span></span></span></span><span><span><span><span>-</span></span></span></span><span><span><span><span> </span></span></span></span><span><span><span><span>100% of larvae. Lethal dose of </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G</span></span></span></span><span><span><span><span> killing 50% of larvae was estimated at 5.24 × 10<sup>-8</sup> mg/m<sup>2</sup> for <i>An.</i> <i>coluzzii</i> and 1.25 × 10<sup>-8</sup> mg/m<sup>2</sup> for <i>Cx.</i> <i>quinquefasciatus</i>. The lethal concentration inducing 95% mortality was estimated at 3.13 × 10<sup>-7</sup> mg/m<sup>2</sup> for <i>An.</i> <i>coluzzii</i> and 2.5 × 10<sup>-8</sup> <span>mg/m<sup>2</sup> for <i>Cx.</i> <i>quinquefasciatus</i>. Open field trials tests indicated that </span>sub-lethal concentrations of </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G</span></span></span></span><span><span><span><span> successfully killed 100% <i>An.</i> <i>gambiae</i> s.l. larvae within 24 hours, while with <i>Culex</i> spp. larvae, 100% mortality was recorded after 48 hours post-treatment. Natural recolonization of water containers by larvae was recorded between 3 and 6 days respectively after the treatment with sublethal doses. Late instar larvae were recorded 5 and 6 days after treatment. When the jars were treated with reference dosage or supra doses of </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G,</span></span></span></span><span><span><span><span> recolonization of water containers was observed six days after treatments. No pupae of both species were found 6 and 7 days post-treatment. <strong>Conclusions:</strong> The study indicated high efficacy of the microbial larvicide </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G</span></span></span></span><span><span><span><span> against <i>Anopheline</i> and <i>Culex</i> larvae. Microbial larvicides such as </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G</span></span></span></span><span><span><span><span> could be appropriate for controlling mosquito population particularly in areas experiencing high insecticide resistance or outdoor biting mosquitoes.</span></span></span></span>展开更多
Objective: To investigate phytochemicals present in the essential oil from aerial parts of eastern red cedar, Juniperus virginiana(J. virginiana) L.(Cupressaceae) and to determine its killing and repellent activities ...Objective: To investigate phytochemicals present in the essential oil from aerial parts of eastern red cedar, Juniperus virginiana(J. virginiana) L.(Cupressaceae) and to determine its killing and repellent activities against larvae, pupae, and adults of the Asian malaria mosquito, Anopheles stephensi(Diptera: Culicidae). Methods: J. virginiana essential oil was extracted by hydrodistillation, and its chemical composition was determined by gas chromatography-mass spectrometry. Seven different logarithmic concentrations of J. virginiana essential oils were used in larvicidal and pupicidal assays. J. virginiana essential oils-impregnated bed nets were applied in a designed animal module to test excito-repellent activity against adult mosquitoes. Results: Fourteen constituents corresponding to 99.98% of J. virginiana essential oils were identified. Five main components were terpinen-4-ol(25.21%), camphor(19.89%), E-3-hexen-1-ol(13.30%), γ-terpinene(7.86%), and l-menthone(2.27%). The LC_(50) and LC_(90) values against larvae of the Anopheles stephensi were 11.693 and 66.140 ppm and for pupae were 9.640 and 40.976 ppm, respectively. In excito-repellency assay, J. virginiana essential oilsimpregnated bed nets provided an average of 54.63% protection for guinea pig and 45.37% mortality for the mosquitoes. Conclusions: Four monoterpenes and one leaf alcohol were identified by gas chromatographymass spectrometry. J. virginiana essential oils showed potent larvicidal, pupicidal, adulticidal, and repellent activities against Anopheles stephensi at acceptable concentrations. Evaluation of bioactivity of identified chemicals(alone or in combination) will provide new eco-friendly substances for mosquito-management programs.展开更多
Over-expression of the cytochrome P450 CYP6CM1 gene has been associated with imidacloprid resistance in a number of Q and B biotype Bemisia tabaci laboratory strains from distinct geographical origins worldwide. We re...Over-expression of the cytochrome P450 CYP6CM1 gene has been associated with imidacloprid resistance in a number of Q and B biotype Bemisia tabaci laboratory strains from distinct geographical origins worldwide. We recently demonstrated that the Q biotype version of the CYP6CM 1 protein （CYP6CMlvQ） is capable of metabolizing imida- cloprid. Here, we show that the levels of BtCYP6CMlvQ were also elevated in laboratory- resistant strains and field-derived populations, with variable imidacloprid resistance levels, collected in Crete. High levels of CYP6CMlvQ transcripts were also determined in survivors of a heterogeneous field population, after exposure to discriminating imidacloprid dosage. Using peptide antibody-based detection assays, we demonstrated that in line with transcriptional data, the CYP6CMlvQ protein levels were higher in imidacloprid-resistant insects, which further implicates the gene as the causal factor of resistance. Finally, assess- ment of the cross-metabolism potential of CYP6CMlvQ against additional neonicotinoid molecules used for B. tabaci control revealed that clothianidin and thiacloprid, but not acetamiprid or thiamethoxam, are metabolized by the recombinant enzyme in vitro.展开更多
Accurate estimates of DNA quantity are likely to become increasingly important for successful genomic screening of insect populations via recently developed, highly multiplexed genotyping assays and high-throughput se...Accurate estimates of DNA quantity are likely to become increasingly important for successful genomic screening of insect populations via recently developed, highly multiplexed genotyping assays and high-throughput sequencing methods. Here we show that genomic DNA extractions from single Anopheles gambiae Giles using a standard commercial kit-based methodology yield extracts with concentrations below the linear range of spectrophotometric absorbance at 260 nm. Concentrations determined by spectropho- tometry were not reproducible, and are therefore neither accurate nor reliable. However, DNA quantification using a fluorescent nucleic acid stain （PicoGreen） gave highly reproducible concentration estimates, and indicated that, on average, single mosquitoes yielded approximately 300 ng of DNA. Such a total yield is currently insufficient for many highthroughput genome screening applications, necessitating whole genome amplification of all or most individuals in a population prior to genotyping.展开更多
The whitefly Bemisia tabaci （Gennadius） is one of the most important pests causing economic losses in a variety of cropping systems around the world. This species was recently found in a coastal region of Colombia a...The whitefly Bemisia tabaci （Gennadius） is one of the most important pests causing economic losses in a variety of cropping systems around the world. This species was recently found in a coastal region of Colombia and has now spread inland. To investigate this invasive process, the genetic structure of B. tabaci was examined in 8 sampling locations from 2 infested regions （coastal, inland） using 9 microsatellite markers and the mitochondrial COI gene. The mitochondrial analysis indicated that only the invasive species of the B. tabaci complex Middle East-Asia Minor 1 （MEAM 1 known previously as biotype B） was present. The microsatellite data pointed to genetic differences among the regions and no isolation by distance within regions. The coastal region in the Caribbean appears to have been the initial point of invasion, while the inland region in the Southwest showed genetic variation among populations most likely reflecting founder events and ongoing changes associated with climatic and topographical heterogeneity. These findings have implications for tracking and managing B. tabaci.展开更多
基金We thank Ms.Michaela Brozenska(Plant Virus and Vector Interactions Group,Division of Crop Protection and Plant Health,Crop Research Institute,Czech Republic)for her excellent technical assistance.We also thank Dr.Beth E.Hazen(Willows End Scientific Editing and Writing Cortland,NY,USA)for editing the English of the manuscript.This work was supported by a grant from the Technology Agency of the Czech Republic(TF02000056).
文摘High-throughput deep-sequencing technology and bioinformatics analysis of the small RNA(sRNA)population isolated from plants allows universal virus detection and complete virome reconstruction for a given sample.In the present sRNA deep-sequencing analysis of virus-infected wheat samples in the Czech Republic,samples were firstly tested for barley yellow dwarf viruses(BYDVs),wheat streak mosaic virus(WSMV)and wheat dwarf virus(WDV)using ELISA,RT-PCR and PCR.Subsequent sRNA sequencing of these samples yielded more than^60 million single-end 50-bp reads with high confidence for nine field samples of wheat.Overall,16.5%of reads were virus-specific and 83.5%were mapped to the host.More 21-nt reads(-7.7E+06 reads)were found than 24-nt(~6.20E+06 reads)or 22-nt(-4.30E+06 reads)reads.De novo assembly of the high-quality contigs revealed the presence of three earlier repoted viruses in the Czech Republic:BYDVs(31.48%),WSMV(24.23%)and WDV(2666%).We also showed the presence of cereal yellow dwarf virus(14.33%;two species CYDV-RPS and CYDV-RPV family Luteoviridae/Polerovirus)and wheat yellow dwarf virus(WYDV,3.30%;Luteoviridae).Phylogenetic analysis showed CYDV and WYDV grouped separately from BYDVs.Furthermore,several recombination breakpoints were found among the groups of yellow dwarf viruses(BYDVs,CYDV,and WYDV).Using RNA deep sequencing,we confirmed the presence of the three known viruses(BYDVs,WSMV,and WDV)and the first record of two species of CYDV and WYDV in wheat in the Czech Republic.
基金Projects from the Ministry of Agriculture of the Czech Republic (NAZV QJ1610186 and MZE-RO0418) supported this work
文摘Stone fruits are an important crop in most parts of the world and are heavily challenged by several viruses including Plum pox virus (PPV), Prune dwarf virus (PDV), Prunus necrotic ringspot virus (PNRSV), and Apple chlorotic leaf spot virus (ACLSV). We validated the PPV resistance in C5 plum plants (commercially known as HoneySweet) grown in the Czech Republic for more than 16 years in a field trial experiment under natural environmental conditions. We quantified single (PPV-Rec) and mixed viruses (PPV-Rec+ACLSV, PPV-Rec+PDV and PPV-Rec+ACLSV+PDV) in C5 transgenic plums inoculated for the period 2016 to 2018. The accumulation of PPV-Rec was high (~5.43E+05 copies) compared with that of ACLSV (~8.70E+04 copies) in the inoculated graft of C5 transgenic plants. Leaves close to the inoculum sources showed a differential level of virus titre in single and mixed infections (~10 to ~5×10^2 copies). C5 plants with permanent virus pressure showed 103- to 105-fold fewer copies of viruses than those of the inoculated graft. We observed high accumulation of conserved miRNAs such as miR167, miR69 and miR396 in C5 plants co-infected with PPV, ACLSV and PDV that are associated with its resistance against viruses. Overall, i) C5 transgenic plums showed high resistance to PPV infection, and a low level (~32 copies) of PPV only accumulated in some grafted plants, ii) high accumulation of PPV was found in inoculated grafts in single PPV infection and mixed infections, iii) heterologous virus infection sustained by ACLSV or PDV did not suppress PPV resistance, and iv) high and low conserved microRNAs accumulated in C5 plants.
基金supported by the grant(No.852)from Pasteur Institute of Iran to A.A.Mehrizi
文摘Objective:To evaluate new compounds synthesized by integrating quinoline,quinazoline,and acridine rings with the active moiety of(5-nitroheteroaryl)methylene hydrazine.Methods:A new series of compounds(1a,1b,2a,2b,3a,and 3b)were synthesized and evaluated for cytotoxicity against COS-7 cells using the MTT assay.In vitro anti-plasmodial activity of the compounds was measured against CQ-sensitive(3D7)and CQ-resistant(K1)Plasmodium(P.)falciparum strains.β-hematin assay was performed to assess the inhibitory effects ofβ-hematin formation for new compounds.Results:The synthetic compounds had anti-plasmodial activity against blood-stage of 3D7[IC50=(0.328-5.483)μM]and K1[IC50=(0.622-7.746)μM]strains of P.falciparum,with no cytotoxicity against COS-7 cells in effective doses.Compounds 1a,1b,and 2b were the most effective derivatives against P.falciparum 3D7 and K1 strains.Based on theβ-hematin assay,the inhibition ofβ-hematin formation is the main mechanism of the inhibitory effect of these compounds.Conclusions:The synthetic compounds could inhibit the erythrocytic stages of CQ-sensitive and resistant P.falciparum strains without toxicity towards mammalian cells.Compounds 1b,2a,and 2b had comparable anti-plasmodial activity against both CQ-sensitive(3D7)and resistant(K1)P.falciparum strains.These compounds may be promising lead structures for the development of new anti-malarial drugs.
基金Supported by Pasteur Institute of Iran and Iran National Science Foundation(Grant No.93011174)
文摘Non-invasive therapeutic methods have recently been used in medical sciences. Enzymes have shown high activity at very low concentrations in laboratories and pharmaceutical,enabling them to play crucial roles in different biological phenomena related to living organism, especially human medicine. Recently, using the therapeutic methods based on non-invasive approaches has been emphasized in medical society. Researchers have focused on producing medicines and tools reducing invasive procedures in medical.Collagenases are proteins which catalyze chemical processes and break the peptide bonds in collagen. Collagen may be generated more than the required amount or produced in unsuitable sites or may not degrade after a certain time. In such cases, using an injectable collagenase or its ointment can be helpful in collagen degradation. In both in vitro and in vivo tests, it has been revealed that collagenases have several therapeutic properties in wound healing, burns, nipple pain and some diseases including intervertebral disc herniation, keloid, cellulite, lipoma among others. This review describes the therapeutic application of collagenase in medical sciences and the process for its production using novel methods, paving the way for more effective and safe applications of collagenases.
文摘<strong>Background: </strong><span><span><span><span>With the rapid expansion of insecticide resistance limiting the effectiveness of insecticide-based vector control interventions, integrated control strategies associating larviciding could be appropriate to improve current control efforts. The present experimental study assesses laboratory and field efficacy of the larvicide </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G</span></span></span></span><span><span><span><span> on <i>Anopheline</i> and <i>Culicine</i> larval stages in Yaoundé. <strong>Methods:</strong> The effect of the larvicide </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G,</span></span></span></span><span><span><span><span> a combination of <i>Bacillus</i><span> <i>thuringiensis</i> var. <i>israelensis</i> </span>(<i>Bti</i>) </span></span></span></span><span><span><span><span>and <i>Bacillus</i> <i>sphaericus</i> (<i>Bs</i>),</span></span></span></span><span><span><span><span> on larval development was assessed during both laboratory and open field trial experiments. Laboratory experiments permitted the evaluation of five different concentrations with four replicates/experiments. Laboratory experiments were conducted with <i>Anopheles</i> <i>coluzzii</i> “Ngousso” and <i>Culex</i> <i>quinquefasciatus</i> laboratory strains. Open field trials were conducted using </span></span></span></span><span><span><span><span>sixteen plastic containers with a diameter of 0.31 m buried in an array of four rows with 4 containers each. Distance between rows and between containers in a row was 1 meter. This experiment permitted to </span></span></span></span><span><span><span><span>test the effect of the microbial larvicide </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G</span></span></span></span><span><span><span><span> under operational application conditions on field mosquito populations. <strong>Results:</strong> <span>The time to induce 100% mortality after exposure to serial concentrations of the larvicide varied according to the dose from 4 - 12 hours for <i>An.</i> <i>coluzzii</i> and 6 - 9 hours for <i>Cx.</i> <i>quinquefasciatus</i> in laboratory experiments. Measurements of the</span> residual activity indicated that all </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G</span></span></span></span><span><span><span><span> concentrations were still active after 35 days and killed 86</span></span></span></span><span><span><span><span>% </span></span></span></span><span><span><span><span>-</span></span></span></span><span><span><span><span> </span></span></span></span><span><span><span><span>100% of larvae. Lethal dose of </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G</span></span></span></span><span><span><span><span> killing 50% of larvae was estimated at 5.24 × 10<sup>-8</sup> mg/m<sup>2</sup> for <i>An.</i> <i>coluzzii</i> and 1.25 × 10<sup>-8</sup> mg/m<sup>2</sup> for <i>Cx.</i> <i>quinquefasciatus</i>. The lethal concentration inducing 95% mortality was estimated at 3.13 × 10<sup>-7</sup> mg/m<sup>2</sup> for <i>An.</i> <i>coluzzii</i> and 2.5 × 10<sup>-8</sup> <span>mg/m<sup>2</sup> for <i>Cx.</i> <i>quinquefasciatus</i>. Open field trials tests indicated that </span>sub-lethal concentrations of </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G</span></span></span></span><span><span><span><span> successfully killed 100% <i>An.</i> <i>gambiae</i> s.l. larvae within 24 hours, while with <i>Culex</i> spp. larvae, 100% mortality was recorded after 48 hours post-treatment. Natural recolonization of water containers by larvae was recorded between 3 and 6 days respectively after the treatment with sublethal doses. Late instar larvae were recorded 5 and 6 days after treatment. When the jars were treated with reference dosage or supra doses of </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G,</span></span></span></span><span><span><span><span> recolonization of water containers was observed six days after treatments. No pupae of both species were found 6 and 7 days post-treatment. <strong>Conclusions:</strong> The study indicated high efficacy of the microbial larvicide </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G</span></span></span></span><span><span><span><span> against <i>Anopheline</i> and <i>Culex</i> larvae. Microbial larvicides such as </span></span></span></span><span><span><span><span>VectoMax</span></span></span></span><span><span><span><span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span></span></span></span><span><span><span><span>G</span></span></span></span><span><span><span><span> could be appropriate for controlling mosquito population particularly in areas experiencing high insecticide resistance or outdoor biting mosquitoes.</span></span></span></span>
文摘Objective: To investigate phytochemicals present in the essential oil from aerial parts of eastern red cedar, Juniperus virginiana(J. virginiana) L.(Cupressaceae) and to determine its killing and repellent activities against larvae, pupae, and adults of the Asian malaria mosquito, Anopheles stephensi(Diptera: Culicidae). Methods: J. virginiana essential oil was extracted by hydrodistillation, and its chemical composition was determined by gas chromatography-mass spectrometry. Seven different logarithmic concentrations of J. virginiana essential oils were used in larvicidal and pupicidal assays. J. virginiana essential oils-impregnated bed nets were applied in a designed animal module to test excito-repellent activity against adult mosquitoes. Results: Fourteen constituents corresponding to 99.98% of J. virginiana essential oils were identified. Five main components were terpinen-4-ol(25.21%), camphor(19.89%), E-3-hexen-1-ol(13.30%), γ-terpinene(7.86%), and l-menthone(2.27%). The LC_(50) and LC_(90) values against larvae of the Anopheles stephensi were 11.693 and 66.140 ppm and for pupae were 9.640 and 40.976 ppm, respectively. In excito-repellency assay, J. virginiana essential oilsimpregnated bed nets provided an average of 54.63% protection for guinea pig and 45.37% mortality for the mosquitoes. Conclusions: Four monoterpenes and one leaf alcohol were identified by gas chromatographymass spectrometry. J. virginiana essential oils showed potent larvicidal, pupicidal, adulticidal, and repellent activities against Anopheles stephensi at acceptable concentrations. Evaluation of bioactivity of identified chemicals(alone or in combination) will provide new eco-friendly substances for mosquito-management programs.
文摘Over-expression of the cytochrome P450 CYP6CM1 gene has been associated with imidacloprid resistance in a number of Q and B biotype Bemisia tabaci laboratory strains from distinct geographical origins worldwide. We recently demonstrated that the Q biotype version of the CYP6CM 1 protein （CYP6CMlvQ） is capable of metabolizing imida- cloprid. Here, we show that the levels of BtCYP6CMlvQ were also elevated in laboratory- resistant strains and field-derived populations, with variable imidacloprid resistance levels, collected in Crete. High levels of CYP6CMlvQ transcripts were also determined in survivors of a heterogeneous field population, after exposure to discriminating imidacloprid dosage. Using peptide antibody-based detection assays, we demonstrated that in line with transcriptional data, the CYP6CMlvQ protein levels were higher in imidacloprid-resistant insects, which further implicates the gene as the causal factor of resistance. Finally, assess- ment of the cross-metabolism potential of CYP6CMlvQ against additional neonicotinoid molecules used for B. tabaci control revealed that clothianidin and thiacloprid, but not acetamiprid or thiamethoxam, are metabolized by the recombinant enzyme in vitro.
文摘Accurate estimates of DNA quantity are likely to become increasingly important for successful genomic screening of insect populations via recently developed, highly multiplexed genotyping assays and high-throughput sequencing methods. Here we show that genomic DNA extractions from single Anopheles gambiae Giles using a standard commercial kit-based methodology yield extracts with concentrations below the linear range of spectrophotometric absorbance at 260 nm. Concentrations determined by spectropho- tometry were not reproducible, and are therefore neither accurate nor reliable. However, DNA quantification using a fluorescent nucleic acid stain （PicoGreen） gave highly reproducible concentration estimates, and indicated that, on average, single mosquitoes yielded approximately 300 ng of DNA. Such a total yield is currently insufficient for many highthroughput genome screening applications, necessitating whole genome amplification of all or most individuals in a population prior to genotyping.
文摘The whitefly Bemisia tabaci （Gennadius） is one of the most important pests causing economic losses in a variety of cropping systems around the world. This species was recently found in a coastal region of Colombia and has now spread inland. To investigate this invasive process, the genetic structure of B. tabaci was examined in 8 sampling locations from 2 infested regions （coastal, inland） using 9 microsatellite markers and the mitochondrial COI gene. The mitochondrial analysis indicated that only the invasive species of the B. tabaci complex Middle East-Asia Minor 1 （MEAM 1 known previously as biotype B） was present. The microsatellite data pointed to genetic differences among the regions and no isolation by distance within regions. The coastal region in the Caribbean appears to have been the initial point of invasion, while the inland region in the Southwest showed genetic variation among populations most likely reflecting founder events and ongoing changes associated with climatic and topographical heterogeneity. These findings have implications for tracking and managing B. tabaci.
