美国密歇根州立大学研究人员4月1日公布研究报告称，他们开发出一种利用沃尔巴克氏菌阻止登革热传播的方法，这项成果将有望用于控制登革热疫情。
研究人员表示，自然界中约28％的蚊子体内天然携带共生菌沃尔巴克氏菌，不过登革热的主要传播者――埃及伊蚊体内却不携带这种细菌。由于沃尔巴克氏菌可以阻止登革病毒在蚊子体内复制，如果能将自然界的埃及伊蚊都感染上这一共生菌，这种蚊子就无法向人类传播登革热。研究人员在实验室中已利用这种方法使伊蚊种群显著降低了传播登革病毒的能力。
据研究人员介绍，他们首先通过显微注射法将沃尔巴克氏菌注入伊蚊胚胎内，以感染其生殖系统，使得该细菌可通过经卵传递从雌蚊传给下一代，从而建立了稳定的感染代系。感染的成蚊可与种群中的异性交配，并繁衍后代。经过多代繁殖，蚊子种群中越来越多成员成为沃尔巴克氏菌携带者。当细菌扩散到整个蚊子种群中，它也赋予蚊群抗登革病毒的能力，从而使之无法传播该病毒了。
相关研究成果1日刊登在美国《公共科学图书馆病原体》杂志上。领导这项研究的密歇根州立大学助理教授奚志勇在接受新华社记者电话采访时表示，通过常规方法很难使蚊子感染沃尔巴克氏菌，因此他们在研究中采用了胚胎注射法。
据奚志勇介绍，澳大利亚研究人员近期也进行了类似研究，不同之处在于两项研究所用的沃尔巴克氏菌菌株不同，但两种方法可谓殊途同归，均表明可直接利用沃尔巴克氏菌防止登革热传播。
登革热是一种急性病毒传染病，分为普通登革热和出血性登革热，后者死亡率较高。据世界卫生组织估计，全球每年约有5000万人感染登革热。(生物谷Bioon.com)
生物谷推荐原文出处：
PLoS Pathogens doi:10.1371/journal.ppat.1000833
The Endosymbiotic Bacterium Wolbachia Induces Resistance to Dengue Virus in Aedes aegypti
Guowu Bian1, Yao Xu1, Peng Lu1, Yan Xie2, Zhiyong Xi1*
1 Department of Entomology and Genetics Program, Michigan State University, East Lansing, Michigan, United States of America, 2 Center for Statistical Training " Consulting, Michigan State University, East Lansing, Michigan, United States of America
Genetic strategies that reduce or block pathogen transmission by mosquitoes have been proposed as a means of augmenting current control measures to reduce the growing burden of vector-borne diseases. The endosymbiotic bacterium Wolbachia has long been promoted as a potential vehicle for introducing disease-resistance genes into mosquitoes, thereby making them refractory to the human pathogens they transmit. Given the large overlap in tissue distribution and intracellular localization between Wolbachia and dengue virus in mosquitoes, we conducted experiments to characterize their interactions. Our results show that Wolbachia inhibits viral replication and dissemination in the main dengue vector, Aedes aegypti. Moreover, the virus transmission potential of Wolbachia-infected Ae. aegypti was significantly diminished when compared to wild-type mosquitoes that did not harbor Wolbachia. At 14 days post-infection, Wolbachia completely blocked dengue transmission in at least 37.5% of Ae. aegypti mosquitoes. We also observed that this Wolbachia-mediated viral interference was associated with an elevated basal immunity and increased longevity in the mosquitoes. These results underscore the potential usefulness of Wolbachia-based control strategies for population replacement.
