The differences in microbial communities and Tick-Borne pathogens between Dermacentor marginatus and Hyalomma asiaticum collected from the Northwestern Xinjiang Uygur Autonomous Region, China.

BACKGROUND

Ticks are important vectors for the transmission of pathogens, including viruses, bacteria, and protozoa. This study investigated the microbial communities and the dominant tick-borne bacteria carried by ticks collected from Wenquan County and Gurtu Town, northwestern Xinjiang Uygur Autonomous Region (XUAR), China.

METHODS

More than 600 questing ticks were collected each from Gurtu and Wenquan by using the flagging method in 2020. Genomic DNA was extracted from 100 ticks randomly selected from each collection site. High-throughput sequencing of the 16S rDNA V3-V4 region was performed to analyze the composition of the microbial communities. Subsequently, species-specific polymerase chain reaction (PCR) was conducted to confirm the presence of pathogenic bacteria.

RESULTS

The ticks collected from Wenquan and Gurtu were identified as Dermacentor marginatus and Hyalomma asiaticum, respectively. High-throughput sequencing of the 16S rDNA V3-V4 region identified Acinetobacter, Rickettsia and Coxiella as the three genera with the highest relative abundance in D. marginatus, while Francisella was the most abundant genus in H. asiaticum. PCR detected the presence of spotted fever group rickettsiae (SFGR) (55/100), Borrelia burgdorferi (6/100), and B. miyamotoi (4/100) in D. marginatus, as well as B. miyamotoi (1/100) in H. asiaticum. Phylogenetic analysis revealed that SFGR were genotyped as Rickettsia raoultii (36/55) and R. sibirica (19/55). Borrelia burgdorferi was clustered with B. bavariensis (2/6), B. afzelii (2/6), and B. yangtzensis (2/6). Co-infections of B. burgdorferi and SFGR (3/100) as well as B. miyamotoi and SFGR (3/100) were detected in D. marginatus.

CONCLUSIONS

The present study demonstrated that SFGR were the dominant tick-borne bacteria in D. marginatus collected from Wenquan. Particularly, this study reported for the first time the presence of B. bavariensis, B. yangtzensis, and B. miyamotoi in D. marginatus in China. Extensive and comprehensive investigations into the prevalence of tick-borne pathogens in ticks, host animals, and local populations in XUAR should be conducted.