Molecular characterization of livestock-associated ticks and tick-borne bacteria in Xinjiang, northwestern China

Background Xinjiang Uygur Autonomous Region represents a critical pastoral zone at the livestock–tick–human interface in northwestern China, yet molecular data on tick-borne pathogens in this region remain scarce. Methods Between 2017 and 2018, we collected 6,172 ticks from cattle, sheep, goats, horses, and dogs across 18 counties in Xinjiang. Tick species identification was performed through morphological examination and COI gene barcoding. Pooled samples (n = 55) were screened using PCR and sequencing targeting Rickettsia (gltA, ompA genes), Anaplasma (16S rRNA), Borrelia (groEL), and broad-range bacterial diversity (16S rRNA). Results Seven tick species were identified, with Alveonasus lahorensis (33.7%), Dermacentor marginatus (32.3%), and Rhipicephalus turanicus (19.7%) comprising the dominant species. Rickettsia DNA was detected in 28 of 55 pools (50.9%), with sequences showing relatedness to R. raoultii , R. massiliae , and R. barbariae . Anaplasma capra was identified in D. marginatus collected from goats (1.8% of pools), while Borrelia miyamotoi was detected in R. turanicus from sheep (1.8% of pools). Additional bacterial genera detected included Arsenophonus , Coxiella , and Francisella . Notably, R. massiliae was detected in both eggs and unfed larvae of R. turanicus , providing evidence of vertical transmission. Conclusions This study represents the first comprehensive molecular survey of livestock-associated ticks in Xinjiang, revealing high prevalence of spotted fever group rickettsiae and the presence of emerging tick-borne pathogens. Our findings underscore potential zoonotic risks within pastoral systems and emphasize the critical need for enhanced One Health surveillance strategies at the livestock–human interface in this region.