Detection and phylogenetic analysis of tick-borne bacterial and protozoan pathogens in a forest province of eastern China

Ticks, as obligate blood-sucking ectoparasites, feed on a broad range of vertebrates and transmit a great diversity of pathogenic microorganisms. Some tick-borne pathogens (TBPs) are endemic in China, whereas epidemio-logical studies are limited in Jiangxi, a forest province located in eastern China. Here, we have determined the positivity rates of TBPs in humans, rodents, dogs, goats and ticks, and performed the molecular characterization of TBPs in Jiangxi province. We found a high positivity rate of TBPs in the collected samples, demonstrating 23 (12.92%) samples positive for more than one TBPs. Of those, 11 (6.18%) samples were positive for Rickettsia spp., six (3.37%) Ehrlichia spp./Anaplasma spp., one (0.56%) Bartonella spp., two (1.12%) Borrelia spp., and five (2.81%) Babesia spp. The positivity rates of TBPs varied among ticks, animals, and humans as follow: goats (14/ 37, 37.84%), ticks (8/35, 22.86%), and dogs (1/11, 9.09%). Humans and rodents were negative for TBP pres-ence. Phylogenetic analyses of these TBP sequences revealed the presence of Rickettsia japonica, Ehrlichia min-asensis, and an unclassified Babesia spp. in goats, and Anaplasma phagocytophilum, Borrelia valaisiana, and an unclassified Bartonella spp. in ticks. Furthermore, R. japonica infection was exclusively found in goats with the positivity rate of 29.73%. Our study is the first report of R. japonica in goats around the world. These findings suggest high TBP positivity rates among goats, ticks, and dogs, and diverse TBPs in goats and ticks in the studied sites. Therefore, our results underscore the urgent need to assess TBP-tick-vertebrate-environment interactions and the risk of tick borne disease exposure in humans in the future.

Automated summary

This study investigated the positivity rates of tick-borne pathogens (TBPs) in humans, rodents, dogs, goats, and ticks in Jiangxi province, China. The results showed a high positivity rate of TBPs, with multiple TBPs being detected in some samples. Notably, the first report of Rickettsia japonica infection in goats worldwide was found. These findings highlight the urgent need to assess the risk of tick-borne disease exposure.