美國密西根州立大學研究人員4月1日公布研究報告稱，他們開發出一種利用沃爾巴克氏菌阻止登革熱傳播的方法，這項成果將有望用於控制登革熱疫情。
研究人員表示，自然界中約28％的蚊子體內天然攜帶共生菌沃爾巴克氏菌，不過登革熱的主要傳播者——埃及伊蚊體內卻不攜帶這種細菌。由於沃爾巴克氏菌可以阻止登革病毒在蚊子體內複製，如果能將自然界的埃及伊蚊都感染上這一共生菌，這種蚊子就無法向人類傳播登革熱。研究人員在實驗室中已利用這種方法使伊蚊種群顯著降低了傳播登革病毒的能力。
據研究人員介紹，他們首先通過顯微注射法將沃爾巴克氏菌注入伊蚊胚胎內，以感染其生殖系統，使得該細菌可通過經卵傳遞從雌蚊傳給下一代，從而建立了穩定的感染代系。感染的成蚊可與種群中的異性交配，並繁衍後代。經過多代繁殖，蚊子種群中越來越多成員成為沃爾巴克氏菌攜帶者。當細菌擴散到整個蚊子種群中，它也賦予蚊群抗登革病毒的能力，從而使之無法傳播該病毒了。
相關研究成果1日刊登在美國《公共科學圖書館·病原體》雜誌上。領導這項研究的密西根州立大學助理教授奚志勇在接受新華社記者電話採訪時表示，通過常規方法很難使蚊子感染沃爾巴克氏菌，因此他們在研究中採用了胚胎注射法。
據奚志勇介紹，澳大利亞研究人員近期也進行了類似研究，不同之處在於兩項研究所用的沃爾巴克氏菌菌株不同，但兩種方法可謂殊途同歸，均表明可直接利用沃爾巴克氏菌防止登革熱傳播。
登革熱是一種急性病毒傳染病，分為普通登革熱和出血性登革熱，後者死亡率較高。據世界衛生組織估計，全球每年約有5000萬人感染登革熱。(生物谷Bioon.com)
生物谷推薦原文出處：
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.