Mosquito-borne bacterial communities are shaped by their insect host species, geography and developmental stage

Mosquitoes harbour diverse bacterial communities that are influenced by geography, host species, and developmental stage. Understanding these microbiomes is crucial for assessing their role as vectors and in pathogen dissemination. Here, we compare the bacterial communities of Aedes albopictus and Aedes japonicus across eight countries: six in Europe, the USA, and Japan, using 16S rRNA amplicon sequencing. We find large differences in microbiota composition between mosquito species, with A. albopictus exhibiting lower bacterial diversity than A. japonicus. Geographic variation in bacterial diversity was also evident, with mosquitoes from Japan and the Netherlands harboring the most diverse microbiomes, while Austrian populations displayed the lowest diversity. Developmental stage hads the strongest influence on bacterial composition, with aquatic-associated genera such as Limnohabitans and Hydrogenophaga dominating larvae, whereas adult mosquitoes harbored higher abundances of Acinetobacter and Methylobacterium. No influence of within Aedes species phylogeny on the bacteriome could be observed. A number of bacterial genera with known pathogenic potential, including Pseudomonas, Serratia, Klebsiella, and Acinetobacter, were detected across multiple locations, suggesting that mosquitoes could serve as environmental reservoirs for opportunistic and antimicrobial-resistant bacteria. These findings provide insights into the ecological and epidemiological implications of mosquito microbiomes and emphasize the need for further investigation into their role in pathogen transmission and antimicrobial resistance dissemination.

蚊虫携带多样的细菌群落，其组成受地理环境、宿主物种及发育阶段的影响。解析此类微生物组，对于评估蚊虫作为媒介生物的作用及病原体传播机制至关重要。本研究通过16S rRNA扩增子测序（16S rRNA amplicon sequencing）技术，对比了来自8个国家（欧洲6国、美国及日本）的白纹伊蚊（Aedes albopictus）与日本伊蚊（Aedes japonicus）的细菌群落组成。研究发现不同蚊虫物种间的微生物群组成存在显著差异：白纹伊蚊的细菌多样性低于日本伊蚊。细菌多样性的地理差异同样显著：来自日本与荷兰的蚊虫其微生物组多样性最高，而奥地利种群的多样性最低。发育阶段对细菌组成的影响最为显著：幼虫阶段以Limnohabitans属（Limnohabitans）与Hydrogenophaga属（Hydrogenophaga）等与水生环境相关的菌属为主，而成蚊体内则以不动杆菌属（Acinetobacter）和甲基杆菌属（Methylobacterium）的丰度更高。未观察到伊蚊属内物种系统发育关系对细菌组的影响。多个位点均检测到具备已知致病潜力的细菌属，包括假单胞菌属（Pseudomonas）、沙雷氏菌属（Serratia）、克雷伯氏菌属（Klebsiella）以及不动杆菌属（Acinetobacter），这表明蚊虫可作为机会致病菌及抗微生物耐药菌的环境储存宿主。本研究结果为蚊虫微生物组的生态学与流行病学意义提供了新认知，并强调需进一步探究其在病原体传播及抗微生物耐药性传播中的作用。