Molecular Biology Research Laboratory, Department of Zoology, Center for Advance Studies, University of Pune, Pune, India.
PLoS One. 2012;7(7):e40401. doi: 10.1371/journal.pone.0040401. Epub 2012 Jul 27.
Mosquito midgut plays a crucial role in its vector susceptibility and pathogen interaction. Identification of the sustainable microflora of the midgut environment can therefore help in evaluating its contribution in mosquito-pathogen interaction and in turn vector competence. To understand the bacterial diversity in the midgut of Aedes aegypti mosquitoes, we conducted a screening study of the gut microbes of these mosquitoes which were either collected from fields or reared in the laboratory "culture-dependent" approach. This work demonstrated that the microbial flora of larvae and adult Ae. aegypti midgut is complex and is dominated by gram negative proteobacteria. Serratia odorifera was found to be stably associated in the midguts of field collected and laboratory reared larvae and adult females. The potential influence of this sustainable gut microbe on DENV-2 susceptibility of this vector was evaluated by co-feeding S. odorifera with DENV-2 to adult Ae. aegypti females (free of gut flora). The observations revealed that the viral susceptibility of these Aedes females enhanced significantly as compared to solely dengue-2 fed and another gut inhabitant, Microbacterium oxydans co-fed females. Based on the results of this study we proposed that the enhancement in the DENV-2 susceptibility of Ae. aegypti females was due to blocking of prohibitin molecule present on the midgut surface of these females by the polypeptide of gut inhabitant S. odorifera.
蚊虫的中肠在其媒介易感性和病原体相互作用中起着至关重要的作用。因此，鉴定中肠环境中可持续存在的微生物群落有助于评估其在蚊虫-病原体相互作用中的贡献，并进而评估媒介能力。为了了解埃及伊蚊中肠内的细菌多样性，我们采用“依赖培养”的方法，对从野外采集或实验室饲养的蚊虫的肠道微生物进行了筛选研究。这项工作表明，埃及伊蚊幼虫和成虫中肠的微生物菌群复杂，以革兰氏阴性变形菌为主。我们发现，恶臭假单胞菌稳定存在于野外采集和实验室饲养的幼虫和成年雌性蚊虫的中肠内。通过将恶臭假单胞菌与 DENV-2 一起喂食给成年埃及伊蚊雌性（没有肠道菌群），评估了这种可持续肠道微生物对 DENV-2 易感性的潜在影响。观察结果表明，与仅喂食 DENV-2 和另一种肠道寄居菌微杆菌的雌性相比，这些埃及伊蚊雌性对病毒的敏感性显著增强。基于这项研究的结果，我们提出，埃及伊蚊雌性对 DENV-2 的易感性增强是由于肠道寄居菌恶臭假单胞菌的多肽阻塞了这些雌性中肠表面的抑制素分子。
