Detection of bacteria carried by ticks from the mountain areas of Guizhou, Southwestern China

Abstract Background: Emerging tick-borne bacterial pathogens pose a threat to public health. The bacterial community and diversity in ticks have been reported with high-throughput sequencing methods that have been widely used in microorganism identification. Tick-borne bacterial pathogens such as Rickettsia, Ehrlichia, Coxiella, and Bartonella amplified by PCR methods have been reported in Guizhou. Little information has been reported on the diversity of the bacterial community in ticks in the areas. The aim of this study was to explore the diversity of the bacterial community in ticks from Guizhou Province, southwestern China. Methods: Ticks were collected in the mountainous areas of three counties in Guizhou Province from 2019-2022. Tick species were identified by morphology and molecular biology. DNA was extracted from tick samples, followed by high-throughput sequencing of the full-length 16S rRNA gene to analyze the diversity of the bacterial community of ticks. Results: A total of 554 ticks were captured, including 453 Rhipicephalus microplus and 101 Haemaphysalis longicornis, from cattle and sheep in Ziyun, Shibing, and Luodian Counties. In total, 823 operational taxonomic units (OTUs) were identified with 13 phyla, 22 classes, 55 orders, 121 families, and 253 genera of bacteria. The dominant bacterial genera were Staphylococcus , Pseudomonas , and Stenotrophomonas . We noticed that Rickettsia and Coxiella were abundant in the samples collected from Luodian County. Other tick-borne pathogens, such as Bartonella, Yersinia, Brucella, Anaplasma , and Francisella, were distinguished in the ticks. Conclusions: These results helped us to understand the diversity of the bacterial community in ticks in Guizhou mountain areas. Further studies are needed to uncover the pathogenicity of these tick-carried bacteria and their potential public health threats.