...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Acta tropica: Journal of Biomedical Sciences >Molecular characterization of the gene profile of Bacillus thuringiensis Berliner isolated from Brazilian ecosystems and showing pathogenic activity against mosquito larvae of medical importance
【24h】

Molecular characterization of the gene profile of Bacillus thuringiensis Berliner isolated from Brazilian ecosystems and showing pathogenic activity against mosquito larvae of medical importance

机译：从巴西生态系统中分离的Bacillus thuringiensis Berliner基因谱的分子表征，并显示医学重要性蚊子幼虫的病原活性

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The occurrence of Aedes aegypti, Culex quinquefasciatus, and mosquitoes of the genus Anopheles potentiate the spread of several diseases, such as dengue, Zika, chikungunya, urban yellow fever, filariasis, and malaria, a situation currently existing in Brazil and in Latin America. Control of the disease vectors is the most effective tool for containing the transmission of the pathogens causing these diseases, and the bacterium Bacillus thuringiensis var. israelensis has been widely used and has shown efficacy over many years. However, new B. thuringiensis (Bt) strains with different gene combinations should be sought for use as an alternative to Bti and to prevent the resistant insects selected. Aiming to identify diversity in the Bt in different Brazilian ecosystems and to assess the pathogenicity of this bacterium to larvae of Ae. aegypti, C. quinquefasciatus, and Anopheles darlingi, Bt strains were obtained from the Amazon, Caatinga (semi-arid region), and Cerrado (Brazilian savanna) biomes and tested in pathogenicity bioassays in third-instar larvae of Ae. aegypti under controlled conditions in the laboratory. The isolates with larvicidal activity to larvae of Ae. aegypti were used in bioassays with the larvae of C. quinquefasciatus and An. darlingi and characterized according to the presence of 14 cry genes (cry1, cry2, cry4, cry10, cry11, cry24, cry32, cry44Aa, cry1Ab, cry4Aa, cry4Ba, ctyl0Aa, cry11Aa, and cry11Ba), six cyt genes (cyt1, cyt2, cyt1Aa, cyt1Ab, cyt2Aa and cyt2Ba), and the chi gene. Four hundred strains of Bt were isolated: 244 from insects, 85 from Amazon soil, and 71 from the Caatinga biome. These strains, in addition to the 153 strains isolated from Cerrado soil and obtained from the Entomopathogenic Bacillus Bank of Maranhao, were tested in bioassays with Ae. aegypti larvae. A total of 37 (6.7%) strains showed larvicidal activity, with positive amplification of the cry, cyt, and chi genes. The most frequently amplified genes were cry4Aa and cry4Ba, both occurring in 59.4% in these strains, followed by cyt1Aa and cyt2Aa, with 56.7% and 48% occurrence, respectively. Twelve (2.2%) strains that presented 100% mortality within 24 h were used in bioassays to estimate the median lethal concentration (LC50) for Ae. aegypti larvae. Two strains (BtMA-690 and BtMA-1114) showed toxicity equal to that of the Bti standard strain, and the same LC50 value (0.003 mg/L) was recorded for the three bacteria after 48 h of exposure. Detection of the presence of the Bt strains that showed pathogenicity for mosquito larvae in the three biomes studied was possible. Therefore, these strains are promising for the control of insect vectors, particularly the BtMA-1114 strain, which presents a gene profile different from that of Bti but with the same toxic effect.
机译：AEDES AEGYPTI，CULEX Quinquefasciatus和蚊子的蚊子的发生强调了几种疾病的蔓延，如登革热，ZIKA，Chikungunya，城市黄热病，丝虫病和疟疾，这一情况目前在巴西和拉丁美洲存在于拉丁美洲。对疾病载体的控制是含有导致这些疾病的病原体传播的最有效工具，并且芽孢杆菌菌丝硫脲。以色列人已被广泛使用，并在多年上显示了疗效。然而，应寻求具有不同基因组合的新的B. thuringiensis（BT）菌株作为BTI的替代品，并防止选择耐药昆虫。旨在识别不同巴西生态系统中BT的多样性，并评估该细菌对AE幼虫的致病性。 AEGYPTI，C. Quinquefasciatus和Anopheles Darlingi，BT菌株是从亚马逊，凯瑟（半干旱地区）和Cerrado（巴西大草原）生物群中获得的，并在AE的第三龄幼虫中致病性生物测定。在实验室的受控条件下的Aegypti。与AE的幼虫的幼虫活性分离物。 Aegypti用C. Quinquefasciatus和An的幼虫用于生物测定。 Darlingi并根据14个Cry基因的存在特征（Cry1，Cry2，Cry4，Cry10，Cry11，Cry24，Cry32，Cry44aa，Cry1ab，Cry4aa，Cry4ba，Ctyl0aa，Cry11aa和Cry11ba），六个cyt基因（cyt1，cyt2， cyt1aa，cyt1ab，cyt2aa和cyt2ba）和chi基因。孤立四百个BT菌株：244来自昆虫，85来自亚马逊土壤，71来自Caatinga Biome。除了从沙拉多水土中分离的153个菌株和从马拉豪的昆虫疗法的昆虫肺肿并池中获得的153株，在Bioassays中用AE测试这些菌株。 Aegypti幼虫。共有37个（6.7％）的菌株显示幼稚活性，碱性扩增，Cyt和Chi基因。最常见的扩增基因是Cry4AA和Cry4Ba，这些菌株中的59.4％发生在59.4％，其次是Cyt1aa和Cyt2aa，分别发生56.7％和48％的发生。在2.2小时内呈现100％死亡率的12个（2.2％）菌株用于生物测定中以​​估计AE的中值致死浓度（LC50）。 Aegypti幼虫。两个菌株（BTMA-690和BTMA-1114）显示出与BTI标准菌株的毒性等于BTI标准菌株的毒性，并且在暴露48小时后为三种细菌记录相同的LC50值（0.003mg / L）。检测在研究的三种生物群中显示出蚊子幼虫的致病性的BT菌株的存在。因此，这些菌株对昆虫载体的控制有前途，特别是BTMA-1114菌株，这呈现了与BTI不同的基因分布，而是具有相同的毒性效应。

著录项

相似文献

  • 外文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号