Anaplasmosis is caused by obligate intracellular bacteria in the genus Anaplasma. These bacterial pathogens are transmitted by ticks and impact both human and animal health. This study was conducted to determine the prevalence and molecular characterization of Anaplasma spp. in ruminants sampled in Xinjiang, northwest China. A survey was performed in August 2012 in rural areas of six counties in Xinjiang province. A total of 250 blood samples from ruminants were collected and tested for the presence of Anaplasma spp. by PCR. Positive samples were genetically characterized based on the 16S rRNA and msp4 genes. The results showed a high prevalence of Anaplasma spp. in ruminants, with at least three different Anaplasma species detected (A. phagocytophilum, A. bovis and A. ovis). The mean prevalence of single infection with each species was 17.6% (A. phagocytophilum), 4.8% (A. bovis) and 40.5% (A. ovis). Coinfection occurred in 20 (8.0%) animals. Phylogenetic analysis of the 16S rRNA gene of A. bovis and A. phagocytophilum revealed a higher degree of genetic diversity for the latter. The results for A. ovis showed genotypic variation among geographic regions in China. In addition, a closely related isolate to the canine pathogen A. platys was identified in ruminants. This survey revealed a high prevalence of Anaplasma sp. infections in sheep and cattle in the northwestern border regions of China, indicating the potential risk of transboundary disease.

Anaplasma spp. are tick-transmitted bacteria that infect a wide variety of wild and domestic animals. These pathogens exhibit a high degree of biological diversity, broad geographical distribution, and represent a serious threat to veterinary and public health worldwide. A novel Anaplasma species was identified in Haemaphysalis qinghaiensis (Ixodidae) in northwestern China and was molecularly characterized by comparison of 16S rRNA, gltA, and groEL gene sequences. Of the 414 samples tested, 24 (5.8%) were positive for this Anaplasma species. On the basis of the 16S rRNA gene, this organism has been found to be closely related to and exhibit the highest sequence similarity with A. capra (99.8–99.9%) that was identified in goats and humans in northern China, but was distinct from other known Anaplasma species. Sequence analysis of the gltA and groEL genes revealed that this Anaplasma species was distinct from A. capra considering the lower sequence identity (88.6–88.7% for gltA and 90.6–91.0% for groEL) and a divergent phylogenetic position. Therefore, we described this Anaplasma species as A. capra-like bacteria. The present study reports a potential novel Anaplasma species closely related to A. capra in H. qinghaiensis in northwestern China. The zoonotic potential of A. capra-like bacteria needs to be further determined.

Tick-borne diseases currently represent an important issue for global health. A number of emerging tick-transmitted microbes continue to be discovered, and some of these are already identified as the cause of human infections. Over the past two decades, Anaplasma phagocytophilum is considered to be mainly responsible for human anaplasmosis. However, a novel zoonotic pathogen provisionally named “Anaplasma capra” has recently been identified in China. In this study, we did an active surveillance of A. capra in goats and sheep in different geographical regions of China. The presence of A. capra was determined by nested PCR in 547 blood samples collected from goats and sheep from 24 counties distributed in 12 provinces in China. The molecular characterization of A. capra isolates in sheep and goats was achieved based on four conventional genetic markers (16S rRNA, gltA, groEL and msp4 genes). Anaplasma capra was identified in 75 of 547 animals, with an overall prevalence of 13.7%. The infection rates in the survey sites ranged from 0 to 78.6%, and were significantly different (P < 0.01). Phylogenetic analysis revealed that the isolates obtained from goats, sheep, Ixodes persulcatus ticks and humans create a separate clade within the genus Anaplasma and distinct from other recognized Anaplasma species. These findings indicated that these A. capra isolates possess the same molecular characteristics, suggesting that this organism could be a substantial health threat to both animals and humans. Anaplasma capra is an emerging tick-transmitted zoonotic pathogen. This novel Anaplasna species is widespread across China with an overall prevalence of 13.7% in goats and sheep with isolates indistinguishable from those found in humans. These findings warrant increased public health awareness for human anaplasmosis.

Anaplasma species are tick-transmitted obligate intracellular bacteria that infect many wild and domestic animals and humans. The prevalence of Anaplasma spp. in ixodid ticks of Qinghai Province is poorly understood. In this study, a total of 1104 questing adult ticks were investigated for the infection of Anaplasma species. As a result, we demonstrated the total infection rates of 3.1, 11.1, 5.6, and 4.5% for A. phagocytophilum, A. bovis, A. ovis and A. capra, respectively. All of the tick samples were negative for A. marginale. The positive rates of A. phagocytophilum, A. ovis and A. capra in different tick species were significantly different. The positive rates of A. capra and A. bovis in the male ticks were significantly higher than that in the female ticks. Sequence analysis of A. ovis showed 99.5–100% identity to the previous reported isolates. The sequences of A. phagocytophilum had 100% identity to strains Ap-SHX21, JC3–3 and ZAM dog-181 from sheep, Mongolian gazelles, and dogs. Two genotypes of A. capra were found based on 16S rRNA, citrate synthase (gltA) gene and heat shock protein (groEL) gene analysis. In conclusion, A. bovis, A. ovis, A. phagocytophilum, and A. capra were present in the ticks in Qinghai Province. Anaplasma infection is associated with tick species, gender and distribution. These data will be helpful for understanding prevalence status of Anaplasma infections in ticks in Qinghai-Tibet Plateau.

To date, anaplasmosis has been reported to be a subclinical disease in Indian and Arabian one-humped camels (Camelus dromedarius) and llamas (Lama glama). However, no information on Anaplasma infection in two-humped Bactrian camels (Camelus bactrianus) in China has been published to date. The aim of this study was to investigate the prevalence of Anaplasma spp. in domestic Bactrian camels and ticks in Xinjiang, China. A total of 382 ticks were collected from the Bactrian camels and from environmental sources. Of these, 84 were morphologically identified as belonging to the Rhipicephalus sanguineus group and genetically identified (12S rDNA, 16S rDNA and the cytochrome c oxidase 1 genes) as R. sanguineus group ticks (temporally designated as Rhipicephalus sp. Xinjiang). PCR testing showed that 7.2 % (20/279) of the camels harbored Anaplasma platys DNA. However, microscopic examination revealed no A. platys inclusions in blood smears from the camels. The PCR prevalence of A. platys DNA was 9.5 % (6/63) in Rhipicephalus sp. Xinjiang from the Bactrian camels and 14.3 % (3/21) in Rhipicephalus sp. Xinjiang from the vegetation. A. platys DNA was not detected by PCR in other tick species (Hyalomma asiaticum, Dermacentor niveus and Hyalomma dromedarii), and no other Anaplasma species were detected in these samples. This is the first report of A. platys in Bactrian camels in Xinjiang, China. The moderate positivity observed indicates that these animals might be a natural host for this pathogen in China.

Babesiosis is an important haemoparasitic disease, caused by the infection and subsequent intra-erythrocytic multiplication of protozoa of the genus Babesia that impacts the livestock industry and animal health. The distribution, epidemiology and genetic characterization of B. bigemina, B. bovis, and B. ovata in cattle in China as well as the prevalence of these protozoan agents were assessed. A total of 646 blood specimens from cattle, dairy cattle and yaks from 14 provinces were collected and tested for the presence of the three Babesia species via a specific nested PCR assay based on the rap-1 and ama-1 genes. The PCR results were confirmed by DNA sequencing. Gene sequences and the genetic characterization were determined for selected positive samples from each sampling area. Of a total of 646 samples, 134 (20.7 %), 60 (9.3 %) and 10 (1.5 %) were positive for B. bovis, B. bigemina and B. ovata infections, respectively. Mixed infections were found in 7 of 14 provinces; 43 (6.7 %) samples were infected with B. bovis and B. bigemina. Three samples (0.5 %) exhibited a co-infection with B. bovis and B. ovata, and 6 (0.9 %) were infected with all three parasites. The rap-1a gene of B. bovis indicated a high degree of sequence heterogeneity compared with other published rap-1a sequences worldwide and was 85–100 % identical to B. bovis rap-1a sequences in Chinese isolates. B. bigemina rap-1c and B. ovata ama-1 genes were nearly identical, with 97.8–99.3 % and 97.8–99.6 % sequence identity, respectively, in GenBank. Positive rates of B. bovis and B. bigemina infection are somewhat high in China. The B. bovis infection in yaks was first reported. The significant sequence heterogeneity in different variants of the rap-1a gene from Chinese B. bovis isolates might be a great threat to the cattle industry if RAP-1a protein is used as immunological antigen against Babesia infections in China. The data obtained in this study can be used to plan effective control strategies against babesiosis in China.