生物谷報道：研究者說，去年Chikungunya病毒已經(jīng)傳播到一些新的國家,，因?yàn)榘l(fā)現(xiàn)一種新品種的蚊子傳播它。一種單一突變使病毒感染亞洲虎蚊子,，而這種蚊子在歐洲和北美的許多國家存在,。
美國得克薩斯州大學(xué)醫(yī)學(xué)院的Stephen Higgs及其同事在公共科學(xué)圖書館《PLoS病原雜志》（PLoS Pathogens，生物谷注）上,，發(fā)表的文章中說,，這種突變增加了Chikungunya病毒永久性擴(kuò)大到歐洲和美洲的可能性。他們說,，隨著全球變暖,，平均溫度持續(xù)升高，這種可能性也增加,。今年病毒引起印度和意大利爆發(fā)流行,。
Chikungunya是一種arbovirus病毒，多數(shù)由Aedes aegypti病毒攜帶,。2004年在肯尼亞流行,，并傳播到一些印度洋島嶼。在小的聯(lián)合島嶼,，三分之一以上的人,，266000人，受到感染,，260人死亡,。但是Aedes aegypti蚊子在聯(lián)合島嶼上沒有發(fā)現(xiàn),，所以研究者懷疑還有其他的動物攜帶病毒。已知引起聯(lián)合島嶼疾病爆發(fā)的病毒出現(xiàn)突變,，研究者對此進(jìn)行檢測,，看病毒突變是否具有感染其他蚊子物種的能力。他們試圖用遺傳工程的病毒株感染多種蚊子,，包括亞洲虎蚊子和Aedes albopictus,。發(fā)現(xiàn)有非常單純突變的病毒在虎蚊中存活。
他們寫道,，這項(xiàng)研究提出新的觀點(diǎn),，如何人類病原的一個單純遺傳學(xué)改變會增加宿主范圍，從而導(dǎo)致地理學(xué)分布改變,。Aedes albopictus是一種廣泛存在的蚊子,，主要分布在歐洲和美國的城市地區(qū)，這項(xiàng)工作提示這些地區(qū)易于感染Chikungunya病毒,。（中國公眾科技網(wǎng)）
生物谷推薦英文原文：
PLoS Pathogens Vol. 3, No. 12, e201 doi:10.1371/journal.ppat.0030201
A Single Mutation in Chikungunya Virus Affects Vector Specificity and Epidemic Potential
Konstantin A. Tsetsarkin, Dana L. Vanlandingham, Charles E. McGee, Stephen Higgs*
1 Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
Chikungunya virus (CHIKV) is an emerging arbovirus associated with several recent large-scale epidemics. The 2005–2006 epidemic on Reunion island that resulted in approximately 266,000 human cases was associated with a strain of CHIKV with a mutation in the envelope protein gene (E1-A226V). To test the hypothesis that this mutation in the epidemic CHIKV (strain LR2006 OPY1) might influence fitness for different vector species, viral infectivity, dissemination, and transmission of CHIKV were compared in Aedes albopictus, the species implicated in the epidemic, and the recognized vector Ae. aegypti. Using viral infectious clones of the Reunion strain and a West African strain of CHIKV, into which either the E1–226 A or V mutation was engineered, we demonstrated that the E1-A226V mutation was directly responsible for a significant increase in CHIKV infectivity for Ae. albopictus, and led to more efficient viral dissemination into mosquito secondary organs and transmission to suckling mice. This mutation caused a marginal decrease in CHIKV Ae. aegypti midgut infectivity, had no effect on viral dissemination, and was associated with a slight increase in transmission by Ae. aegypti to suckling mice in competition experiments. The effect of the E1-A226V mutation on cholesterol dependence of CHIKV was also analyzed, revealing an association between cholesterol dependence and increased fitness of CHIKV in Ae. albopictus. Our observation that a single amino acid substitution can influence vector specificity provides a plausible explanation of how this mutant virus caused an epidemic in a region lacking the typical vector. This has important implications with respect to how viruses may establish a transmission cycle when introduced into a new area. Due to the widespread distribution of Ae. albopictus, this mutation increases the potential for CHIKV to permanently extend its range into Europe and the Americas.
Funding. D. L. Vanlandingham was supported in part by NIH T32 A107536. C. E. McGee was supported by a Centers for Disease Control and Prevention Fellowship Training Program in Vector-Borne Infectious Diseases TOI/CCT622892 and NIH T32 AI 07526 Training Grant in Emerging and Tropical Infectious Diseases. This study was supported in part by funding from the NIH AI R21 AI073389.
Competing interests. The authors have declared that no competing interests exist.
Editor: Edward C. Holmes, The Pennsylvania State University, United States of America
Citation: Tsetsarkin KA, Vanlandingham DL, McGee CE, Higgs S (2007) A Single Mutation in Chikungunya Virus Affects Vector Specificity and Epidemic Potential. PLoS Pathog 3(12): e201 doi:10.1371/journal.ppat.0030201
Received: September 20, 2007; Accepted: November 12, 2007; Published: December 7, 2007
Copyright: © 2007 Tsetsarkin et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
* To whom correspondence should be addressed. E-mail: [email protected]
英文全文鏈接：
ttp://pathogens.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.ppat.0030201
