Table_4_Metagenome Sequencing Reveals the Midgut Microbiota Makeup of Culex pipiens quinquefasciatus and Its Possible Relationship With Insecticide Resistance.DOCX

Midgut microbiota can participate in the detoxification and metabolism processes in insects, but there are few reports on the relationship between midgut microbiota and insecticide resistance in mosquitoes. In this study, we performed metagenomic sequencing on a susceptible strain (SS), a field-collected Hainan strain (HN), and a deltamethrin-resistant strain (RR) of Culex pipiens quinquefasciatus to understand the diversity and functions of their midgut microbiota. The results revealed differences in midgut microbiota among the three strains of Cx. pipiens quinquefasciatus. At the phylum level, Proteobacteria was the most prominent, accounting for nearly 70% of their midgut microbes. At the genus level, Aeromonas made up the highest proportion. In addition, Aeromonas, Morganella, Elizabethkingia, Enterobacter, Cedecea, and Thorsellia showed significant differences between strains. At the species level, Bacillus cereus, Enterobacter cloacae complex sp. 4DZ3-17B2, Streptomyces sp. CNQ329, and some species of Pseudomonas and Wolbachia were more abundant in the two resistant strains. Principal component analysis (PCA) showed that the SS strain had significantly different metagenomic functions than the two deltamethrin-resistant strains (HN and RR strain). The HN and RR strains differed from the SS strain in more than 10 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The analysis of species abundance and functional diversity can provide directions for future studies.

昆虫中肠微生物群可参与宿主的解毒代谢过程，但目前关于蚊虫中肠菌群与杀虫剂抗性之间关联的研究报道尚少。本研究针对致倦库蚊（Culex pipiens quinquefasciatus）的敏感品系（SS）、野外采集的海南品系（HN）以及溴氰菊酯抗性品系（RR）开展宏基因组测序（metagenomic sequencing），以解析其中肠微生物群的多样性与功能特征。研究结果显示，三种致倦库蚊品系的中肠微生物群组成存在显著差异。在门分类水平上，变形菌门（Proteobacteria）为优势菌群，占中肠微生物总丰度的近70%；在属分类水平上，气单胞菌属（Aeromonas）占比最高。此外，气单胞菌属、摩根氏菌属（Morganella）、伊丽莎白菌属（Elizabethkingia）、肠杆菌属（Enterobacter）、西迪西菌属（Cedecea）以及托尔斯尔菌属（Thorsellia）在不同品系间均存在显著丰度差异。在物种水平上，蜡样芽孢杆菌（Bacillus cereus）、阴沟肠杆菌复合群菌种4DZ3-17B2（Enterobacter cloacae complex sp. 4DZ3-17B2）、链霉菌属菌种CNQ329（Streptomyces sp. CNQ329）以及假单胞菌属（Pseudomonas）和沃尔巴克氏体属（Wolbachia）的部分物种在两种抗性品系中丰度更高。主成分分析（PCA，Principal Component Analysis）结果显示，敏感品系的宏基因组功能特征与两种溴氰菊酯抗性品系（HN及RR品系）存在显著差异。相较于敏感品系，HN与RR品系共有超过10条京都基因与基因组百科全书（KEGG，Kyoto Encyclopedia of Genes and Genomes）通路存在显著差异。本次针对物种丰度与功能多样性的分析可为后续相关研究提供方向指引。