scholarly journals Polycation Peptides Derived from the Primary Structure of Bacillus thuringiensis Cry11Bb Protoxin Permeabilize Aedes aegypti Midgut Mitochondria

2009 ◽  
Vol 96 (3) ◽  
pp. 157a
Author(s):  
Victor V. Lemeshko ◽  
Gabriela Jaramillo ◽  
Sergio Orduz
Acta Tropica ◽  
2021 ◽  
pp. 106088
Author(s):  
Jiangyu Wu ◽  
Li Wei ◽  
Jiali He ◽  
Kang Fu ◽  
Xinxin Li ◽  
...  

Biomédica ◽  
1987 ◽  
Vol 7 (1-2) ◽  
pp. 5 ◽  
Author(s):  
Marco F. Suárez ◽  
Dwight Ayala ◽  
Michael J. Nelson

2006 ◽  
Vol 72 (8) ◽  
pp. 5673-5676 ◽  
Author(s):  
Takeshi Ito ◽  
Tomonori Ikeya ◽  
Ken Sahara ◽  
Hisanori Bando ◽  
Shin-ichiro Asano

ABSTRACT Two novel crystal protein genes, cry30Ba and cry44Aa, were cloned from Bacillus thuringiensis subsp. entomocidus INA288 and expressed in an acrystalliferous strain. Cry44Aa crystals were highly toxic to second-instar Culex pipiens pallens (50% mortality concentration [LC50] = 6 ng/ml) and Aedes aegypti (LC50 = 12 ng/ml); however, Cry30Ba crystals were not toxic.


2008 ◽  
Vol 23 (4) ◽  
pp. 251-258
Author(s):  
Milenka Peric ◽  
Mirjana Prijovic ◽  
Goran Andric

Toxicity and persistence of two formulations based on Bacillus thuringiensis subsp. israelensis applied to Aedes aegypti mosquito larvae were tested under laborabory conditions. The formulations were: a) water dispersible granules (product VectoBac WDG), and b) aqueous suspension (product VectoBac 12AS). The effects of both products on mosquito larvae were tested immediately after their dilution in pure water (zero time) and in 1-, 2-, 8- and 13-day old solutions. The two products were also tested in mixtures of water and clay at a rate of 0.5 g clay/150 ml water immediately after product dilution, and in one-day old solutions containing 0.1 and 0.05 g of clay in the same amount of water. The product VectoBac WDG was persistent and highly effective against Ae. aegypti larvae in pure water after the longest experimental period of 13 days, and significantly more effective than VectoBac 12AS at equal rates of application. The effectiveness of VectoBac 12AS weakened significantly after 8 and 13 days of treatment, compared to the effects at zero time and in 1- and 2-day old solutions. High clay content in water significantly reduced the larvicidal effectiveness of both products, indicating its possible compromising role during product application in practice.


2019 ◽  
Vol 98 (8) ◽  
pp. 893-896
Author(s):  
Svetlana A. Roslavtseva

Mosquito control is necessary to improve the epidemic and, consequently, the sanitary and hygienic situation in human settlements. At the same time, the safest and more environmentally friendly way of controlling is not the fight against adult mosquitoes, but the treatment of reservoirs with microbiological larvicides based on entomopathogenic, aerobic, spore-forming, saprophytic bacteria Bacillus thuringiensis (de Barjac) (Bti). A new serotype of the bacterium B. thuringiensis was found in Israel in the Negev desert. This serotype being more active against larvae of blood-sucking and non-blood-sucking mosquitoes and midges than previously known serotypes, was named israelensis. Bti endotoxin is a typical insecticide with intestinal type of action for different mosquito species. For example, Bti H14 is highly insecticidal to the larvae of Aedes aegypti and Ae. albopictus at very low concentrations. The parasporal body (endotoxin crystal), a crystalline protein consisted of four main polypeptides and two minor polypeptides, possesses of a larvicidal action. Larvicidal activity is associated with a synergistic effect in a combination of four polypeptides. The possibility of development of resistance to products based on Bti and Bacillus sphaericus in populations of mosquitoes (Culicidae) was investigated. The use of domestic microbiological formulations based on Bti («Baktitsid», «Larviol-pasta», and «Antinat») was shown an eradication the larvae of bloodsucking mosquitoes and midges to be possible and rational, since they are not generated resistant populations of mosquitoes. This is confirmed by more than 30 years of the use of such formulations.


2012 ◽  
Vol 10 (2) ◽  
Author(s):  
Rose Gomes Monnerat ◽  
Carlos Marcelo Soares ◽  
Mirian Dos Anjos Santos ◽  
Cristiane Oliveira ◽  
Cristina Cardoso ◽  
...  

2005 ◽  
Vol 38 (4) ◽  
pp. 316-321 ◽  
Author(s):  
Ricardo José Soares Pontes ◽  
Ana Cláudia Ferreira Regazzi ◽  
José Wellington Oliveira Lima ◽  
Lígia Regina Sansígolo Kerr-Pontes

Avaliou-se o efeito residual do temefos (apresentações comerciais A, B, C) e Bacillus thuringiensis israelensis (D e E) sobre larvas de Aedes aegypti, em recipientes com renovação de água. Utilizaram-se 44 béqueres de 1.000ml (8 para cada apresentação e 4 controles). Em cada béquer introduziram-se diariamente 25 larvas. Após 24 horas, contavam-se as larvas mortas, esvaziavam-se os béqueres até 200ml, repunha-se o volume original e acrescentavam-se novas larvas. A duração do efeito residual máximo (100% de mortalidade) foi: A-19; B-39; C-40; D-8; E-19 dias. A razão de mortalidade permaneceu equivalente entre todos os larvicidas durante 25 dias; B e C mostraram RM 2,40 vezes maior do que E entre 46-95 dias; B, comparado com A, mostrou RM 1,90-7,51 vezes maior entre 26-95 dias. Conclui-se pela maior eficácia de duas apresentações do temefos, mesmo em uma situação epidemiológica de longa exposição ao produto e com renovação de água dos recipientes.


2020 ◽  
Vol 57 (6) ◽  
pp. 1852-1856
Author(s):  
Sebastian E González-Villarreal ◽  
Mónica García-Montelongo ◽  
Jorge E Ibarra

Abstract The Cry1C protein family of Bacillus thuringiensis form bipyramidal crystals, which are commonly associated with toxic activity against lepidopteran species; however, some members of this family may also be toxic to dipterans. In the present work, the Cry1Ca16 protein, synthesized by the B. thuringiensis LBIT-1217 strain, was analyzed. The gene coding for this protein was amplified, sequenced, and cloned into the pSTAB vector, which was electro-transferred into the acrystalliferous B. thuringiensis 4Q7 strain. The recombinant strain showed the expected bipyramidal crystal morphology, identical to the original LBIT-1217 strain and exhibited toxicity against larvae of Aedes aegypti (Diptera). Pure crystals from the recombinant strain were used in bioassays against Ae. aegypti larvae, estimating an LC50 of 4.61 μg/ml. Further studies on Cry1Ca16 mosquitocidal potential included joint-action tests with the Cyt1Aa protein crystals from B. thuringiensis israelensis. An LC50 using pure Cyt1Aa crystals was estimated at 0.73 μg/ml, whereas an LC50 of 0.61 μg/ml was estimated when both toxins were tested together. Data from these bioassays was analyzed using joint-action tests such as the Tammes-Bakuniak graphical method and the formula proposed by Tabashnik (1992). Both tests clearly showed a synergistic effect between these two toxins.


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