Ticks can transmit numerous pathogens and harbor diverse microbial communities. Considerable progress has been made in the characterization of the bacterial profiles of ticks, whereas other members of tick microbiota (such as fungi and viruses) and the functional characteristics of ticks warrant further exploration. To investigate the taxonomic and functional profiles and explore potential pathogens they were carrying, samples of different developmental stages and of both sexes of Haemaphysalis longicornis were collected in the present study and the metagenomic deep sequencing method was applied. Metagenomic deep sequencing results revealed that bacteria were predominant, followed by fungi, viruses, archaea and metazoans. Proteobacteria was the dominant phylum in the microbiota of H. longicornis. The abundance of microbial species varied significantly among groups, the bacteria of nymphs and female adults demonstrated unique characteristics, and the microbial community of males overlapped with those of nymphs and females. Functional annotation results demonstrated that the metagenomic sequences of the three groups were classified under metabolism, genetic information processing, environmental information processing and cellular processes. Differences in functional characteristics were observed in both the pathways composition and abundance of carbohydrate-active enzymes. Furthermore, whole metagenome sequencing helped to elucidate the diversity of pathogens carried by H. longicornis, which may facilitate further research attempting to prevent and control tick-borne diseases.

壁虱可以传播多种病原体，并拥有各种微生物群落。壁虱的细菌特征分析已经取得了相当大的进展，而壁虱微生物群的其他成员（例如真菌和病毒）和壁虱的功能特征值得进一步探索。为了调查分类学和功能谱并探究它们携带的潜在病原体，本研究收集了不同发育阶段和长短血吸虫两性的样本，并应用了宏基因组学深度测序方法。元基因组深度测序结果表明，细菌占主导地位，其次是真菌，病毒，古细菌和后生动物。变形杆菌是长柄嗜血菌菌群中的优势菌群s。各组之间微生物种类的丰富度差异很大，若虫和成虫的细菌表现出独特的特征，雄性的微生物群落与若虫和雌性的微生物群落重叠。功能注释结果表明，三组的宏基因组序列被分类为代谢，遗传信息处理，环境信息处理和细胞过程。碳水化合物活性酶的途径组成和丰富度均观察到功能特性的差异。此外，完整的基因组测序有助于阐明由长双歧杆菌携带的病原体的多样性，这可能有助于进一步研究，试图预防和控制tick传疾病。