Department of Conservation Biology and Global Change, Estación Biológica de Doñana (EBD), CSIC, Sevilla, Spain.
Department of Parasitology, Faculty of Pharmacy, University of Granada, Granada, Spain.
PLoS One. 2024 Nov 18;19(11):e0314001. doi: 10.1371/journal.pone.0314001. eCollection 2024.
West Nile virus (WNV) is a flavivirus naturally circulating between mosquito vectors and birds, occasionally infecting horses and humans and causing epidemiologically relevant outbreaks. In Spain, the first big WNV outbreak was recorded in 2020, resulting in 77 people infected and 8 fatalities, most of them in southern Spain. Culex perexiguus was identified as the primary vector of WNV maintaining its enzootic circulation of the virus. Growing evidence highlights the role of mosquito microbiota as a key component determining the vectorial capacity of mosquitoes, largely contributing to disease epidemiology. Here, we develop, to our knowledge, the first identification of the microbiota composition of this mosquito vector under natural conditions and test for the potential relationship between mosquito microbiota composition and WNV infection. To do so, we collected mosquitoes in a natural area of southern Spain during the 2020 WNV outbreak and identified the microbiota composition of mosquitoes using a 16S rRNA gene metabarcoding approach. The microbiota of Cx. perexiguus was dominated by the phylum Proteobacteria. The most abundant families were Burkholderiaceae and Erwiniaceae, including the genera Burkholderia, Erwinia, and Pantoea. The genus Wolbachia, which use to dominate the microbiota of Cx. pipiens and negatively interact with WNV according to the literature, had a low prevalence and relative abundance in Cx. perexiguus and its abundance did not differ between WNV-positive and WNV-negative mosquito pools. The microbiota diversity and composition of Cx. perexiguus were not significantly related to the WNV infection status. These results provide the first identification of the mosquito microbiota in an endemic area of WNV circulation in Spain.
西尼罗河病毒（WNV）是一种黄病毒，在蚊子媒介和鸟类之间自然循环，偶尔感染马和人类，并引起具有流行病学意义的暴发。在西班牙，2020 年首次记录到大规模的 WNV 暴发，导致 77 人感染，8 人死亡，其中大多数在西班牙南部。库蚊属的 Culex perexiguus 被确定为WNV 的主要媒介，维持着病毒的地方性循环。越来越多的证据强调了蚊子微生物组作为决定蚊子媒介能力的关键组成部分的作用，在很大程度上促成了疾病的流行病学。在这里，我们首次在自然条件下确定了这种蚊子媒介的微生物组组成，并测试了蚊子微生物组组成与 WNV 感染之间的潜在关系。为此，我们在 2020 年 WNV 暴发期间在西班牙南部的一个自然区域收集蚊子，并使用 16S rRNA 基因宏条形码方法鉴定蚊子的微生物组组成。Cx. perexiguus 的微生物组主要由变形菌门组成。最丰富的科是伯克霍尔德氏菌科和欧文氏菌科，包括伯克霍尔德菌属、欧文菌属和泛菌属。根据文献，沃尔巴克氏体属通常主导库蚊属和伊蚊属的微生物组，并与 WNV 产生负相互作用，但在 Cx. perexiguus 中的丰度和相对丰度较低，在 WNV 阳性和 WNV 阴性的蚊子群中没有差异。Cx. perexiguus 的微生物组多样性和组成与 WNV 感染状态没有显著关系。这些结果首次确定了西班牙 WNV 流行地区蚊子的微生物组。
