Prevalence of Rickettsia spp., Anaplasma spp. and Ehrlichia spp. in Ornithodoros lahorensis from southern Xinjiang, China

Abstract

Ticks are important vectors for pathogens and transmit a variety of diseases in humans and animals. Numerous studies have reported the presence of Ixodidae ticks and tick-borne pathogens in southern Xinjiang. However, data pertaining to argasid ticks and argasid tick-associated pathogens are sparse. This study collected a total of 407 ticks from southern Xinjiang. The tick species were identified on the basis of their morphological and mitochondrial 16S ribosomal DNA (16S rDNA) characteristics. The citrate synthase gene (gltA), 17-kilodalton antigen gene (17-kDa), and outer membrane protein A and B genes (ompA, ompB) were amplified using four sets of primers. The species of rickettsiae were further identified on the basis of concatenated sequences. To detect Anaplasma and Ehrlichia, nested PCR was used to amplify the Ehrlichia and Anaplasma 16S rRNA genes, respectively. All 407 ticks were Ornithodoros lahorensis. A total of 109 Rickettsia-positive samples and 19 Anaplasma-positive samples were detected in DNA samples from the 407 ticks. R. sibirica, R. massiliae, Candidatus R. barbariae, A. ovis, A. marginale, and A. phagocytophilum were found. All DNA samples from Or. lahorensis were tested for the presence of the Ehrlichia spp. nucleotide, but none of the samples were positive for such pathogens. This is the first time that R. sibirica, R. massiliae, and A. marginale were detected in Or. lahorensis from southern Xinjiang.