Identification of predominant microbial populations carried by five species of ticks in Qingdao, Shandong

  Objective  To understand the predominant microbial populations carried by five species of ticks in Qingdao, Shandong province, and provide evidence for the construction of microbiology resource bank of tick-borne diseases.

  Methods  Ticks carried by hedgehogs in Qingdao were collected in 2019 and classified by morphological identification and 16 s ribosomal RNA sequencing. RNA libraries were constructed according to five species of tick and PE 2×150 sequencing was performed using Illumina NovaSeq6000. Metagenomic analysis and taxonomic analysis were performed on the high-throughput sequencing data, and the genetic evolution of Dabie bandavirus was analyzed.

  Results  The collected ticks were identified as Haemaphysalis flava (n=155), Rhipicephalus sanguineus (n=62), Dermacentor sinicus (n=67), Haemaphysalis longicornis (n=77) and Haemaphysalis campanulata (n=59). The abundance of bacteria varied greatly among five species of tick. A total of 101 species of bacteria were identified from 6 phylas, 19 orders and 35 families. The bacterium with the highest abundance in Haemaphysalis flava and Haemaphysalis campanulata were Micrococcales (37.9%, 71.5%). Pseudonocardales was the bacterium with the highest abundance in the Rhipicephalus sanguineus, Dermacentor sinicus and Haemaphysalis longicornis. The abundances were 51.9%, 49.6% and 34.8%, respectively. The virus abundance of Haemaphysalis flava, Dermacentor sinicus and Haemaphysalis campanulata ranged from 0.28% to 2.82%. The virus abundance of Rhipicephalus sanguineus and Haemaphysalis longicornis were 22.98% and 59.31% respectively. Yongjia tick virus and Dabieshan Tick virus were detected in all five species of tick, and their abundance ranged from 12.0% to 51.4% and from 2.4% to 12.2%, respectively. Nickie virus, Hubei tick virus 3, Wenzhou tick virus 3 and Huangpi tick virus 1 were detected in Haemaphysalis flava. Hubei sobemo-like virus 15 and Dabie bandavirus were only detected in Haemaphysalis longicornis. The L, M and S segments of Dabie bandavirus belong to C2 lineage. The phylogenetic analysis found that the L and M segments had the highest identities with the strains (KR 706567.1 and KR 706566.1) isolated from a patient in Shandong and the S segment showed the highest identity with the strain JQ693006.1 isolated from a patient in Laizhou of Shandong.

  Conclusion  The spectrum of microorganism carried by different speices of tick were diverse in Qingdao. The research results could provide data support for the construction of tick microbial resource bank and tick-borne disease control in Qingdao.