Highly Improved Bacterial Larvicides for Vector Control

描述（由申请人提供）：拟议研究的目的是开发一系列高度改良的重组细菌杀幼虫剂，以控制主要人类疾病的蚊媒，包括疟疾、丝虫病、登革热和病毒性脑炎。这些细菌的成本效益将明显高于苏云金芽孢杆菌亚种、以色列芽孢杆菌（Bti）和球形芽孢杆菌（Bs），后者是目前用于病媒控制的商业细菌杀幼虫剂的有效成分。此外，这些重组将大大降低蚊子对巴西、中国和印度库蚊种群产生球形白僵杆菌抗性的可能性。初步研究表明，在Bti中产生高水平的Bs2362二元蛋白导致重组菌株的效率比其衍生的亲本菌株高10倍。这表明，经过高度改良的细菌可以用于病媒控制。尽管取得了这些令人鼓舞的成果，但重组细菌杀幼虫剂的开发仍受到几个主要障碍的困扰，包括投资回报低、市场规模有限以及重组生物带来的额外监管负担，导致产品开发时间长。目前的项目是加州大学河滨分校和伊利诺伊州利伯蒂维尔市的Valent生物科学公司之间的合作，将结合双方的专业知识，加速开发用于病媒控制的高度改进的细菌杀幼虫剂。通过重点工程研究，将开发出一系列基于Cry、Cyt和b型杀蚊蛋白的更有效的Bti和b型菌株，并将其商业化，这些菌株也符合美国的监管要求。将开发以Bti为宿主细胞的改良菌株，主要用于控制在半污染和高度污染水域中繁殖的库蚊（丝虫病和西尼罗病毒的载体），而Bti将作为宿主细胞用于控制伊蚊（登革热的载体）和某些疟蚊的载体。这次合作的共同目标是在五年内将基于这些重组细菌的新产品推向市场，如果可能的话，越快越好。

DESCRIPTION (provided by applicant): The objective of the proposed research is to develop a series of highly improved recombinant bacterial larvicides for controlling the mosquito vectors of major human diseases including malaria, filariasis, dengue, and the viral encephalitides. These bacteria will be significantly more cost-effective than Bacillus thuringiensis subsp, israelensis (Bti) and Bacillus sphaericus (Bs), the active ingredients of current commercial bacterial larvicides used in vector control. In addition, these recombinants will be much less prone to induce mosquito resistance, which has already developed to B. sphaericus in Culex populations in Brazil, China, and India. Preliminary studies show that the production of high levels of the Bs2362 binary protein in Bti results in a recombinant strain tenfold more effective than the parental strains from which it was derived. This demonstrates that highly improved bacteria can be engineered for use in vector control. Despite these encouraging results, the development of recombinant bacterial larvicides is plagued by several major hurdles including low returns on investment, limited market size, and additional regulatory burdens imposed on recombinant organisms that result in long product development times. The present project is a collaboration between the University of California, Riverside and Valent BioSciences of Libertyville, Illinois, that will combine the expertise of both parties to accelerate the development highly improved bacterial larvicides for vector control. Through focused engineering research, a series of much more effective strains of Bti and Bs based on Cry, Cyt, and Bs mosquitocidal proteins will be developed and commercialized that also meet U.S. regulatory requirements. Improved strains using Bs as a host cell will be developed primarily for control of Culex species (vectors of filariasis and West Nile Virus) breeding in semi-polluted and highly polluted waters, whereas Bti will be used as the host cell for control of Aedes species (vectors of dengue) and certain anopheline vectors of malaria. This collaboration has the common goal of having new products based on these recombinant bacteria on the market within five years, sooner if possible.