Investigation of tick-borne bacterial microorganisms in Haemaphysalis ticks from Hebei, Shandong, and Qinghai provinces, China

Tick-borne microorganisms in many tick species and many areas of China are still not thoroughly investigated. In this study, 224 ticks including two species (Haemaphysalis longicornis and Haemaphysalis qinghaiensis) were collected from four cities in Hebei, Shandong, and Qinghai provinces, China. Ticks were screened for the presence of tick-borne bacterial microorganisms including Rickettsia, Anaplasmataceae (Anaplasma, Ehrlichia, Neoehrlichia, etc.), Coxiella, Borrelia, and Bartonella. Two Anaplasma species (Anaplasma ovis and Anaplasma capra) were detected in H. longicornis from Xingtai City of Hebei Province, with a positive rate of 3 % and 8 %, respectively. A Coxiella species was detected in H. longicornis ticks from all three locations in Hebei and Shandong provinces, with the positive rate ranging from 30 to 75 %. All the 16S and rpoB sequences were very similar (99.77-100 % identity) to Coxiella endosymbiont of Haemaphysalis ticks. An Ehrlichia species was detected in H. qinghaiensis (6/66, 9 %) from Xining City, Qinghai Province. The 16S and groEL sequences had 100 % and 97.40-97.85 % nucleotide identities to "Candidatus Ehrlichia pampeana" strains, respectively, suggesting that it may be a variant of "Candidatus Ehrlichia pampeana". All the ticks were negative for Rickettsia, Borrelia, and Bartonella. Because all the ticks were removed from goats or humans and were partially or fully engorged, it is possible that the microorganisms were from the blood meal but not vectored by the ticks. Our results may provide some information on the diversity and distribution of tick-borne pathogens in China.

Epidemiological and phylogenetic characteristics of emerging Anaplasma capra: A systematic review with modeling analysis

Anaplasma capra, an emerging tick-borne pathogen, has caused a lot of concern since initially recognized in goats and patients in China in 2015, and has been reported in a wide range of domestic and wild animals as well as ticks worldwide, posing a threat to public health. In this systematic review, we established a comprehensive database to acquire the distribution and prevalence status of this pathogen, and collected all sequences of A. capra to summarize the details of genetic diversity by phylogenetic analysis. We also predicted the possible global distribution of A. capra by using ecological niche model. A. capra has been known to distribute in 18 countries across Asia, Europe and Africa. A total of 19 species of mammals from seven families have been reported as hosts, and domestic ruminants including goats, sheep and cattle were the major hosts. At least 8 tick species of 4 genera have been reported to carry A. capra, and Haemaphysalis longicornis was most commonly infected. Sheep and Rhipicephalus microplus had the highest positive rates among animals and ticks. Phylogenetic analysis based on gltA and groEL genes revealed that A. capra could primarily be divided into two clusters related to geographic location and animal hosts. The predictive model showed that the most suitable habitats for presence of A. capra were mainly located in Asia and eastern Europe. These cumulative data regarding A. capra of our study lay a foundation for the subsequent exploration of this emerging tick-borne pathogen.

First Detection of Theileria sinensis-like and Anaplasma capra in Ixodes kashmiricus: With Notes on cox1-Based Phylogenetic Position and New Locality Records

Ixodes ticks transmit Theileria and Anaplasma species to a wide range of animals. The spreading of ticks and tick-borne pathogens has been attributed to transhumant herds, and research on these uninvestigated issues has been neglected in many countries, including Pakistan. Recently, we used internal transcribed spacer (ITS) and 16S ribosomal DNA partial sequences to genetically characterize Ixodes kashmiricus ticks and their associated Rickettsia spp. However, the data on its cox1 sequence and associated Theileria spp. and Anaplasma spp. are missing. This study aimed to genetically characterize I. kashmiricus based on the cox1 sequence and their associated Theileria spp. and Anaplasma spp. The I. kashmiricus ticks were collected from small ruminants: sheep (Ovis aries) and goats (Capra hircus) of transhumant herds in district Shangla, Dir Upper and Chitral, Khyber Pakhtunkhwa (KP), Pakistan. Out of 129 examined hosts, 94 (72.87%) (56 sheep and 38 goats) were infested by 352 ticks, including adult females (175; 49.7%) followed by nymphs (115; 32.7%) and males (62; 17.6%). For molecular analyses, 121 ticks were subjected to DNA isolation and PCR for the amplification of the cox1 sequence for I. kashmiricus, 18S rDNA for Theileria spp. and 16S rDNA sequences for Anaplasma spp. The obtained cox1 sequence showed 89.29%, 88.78%, and 88.71% identity with Ixodes scapularis, Ixodes gibbosus, and Ixodes apronophorus, respectively. Phylogenetically, the present cox1 sequence clustered with the Ixodes ricinus complex. Additionally, the 18S rDNA sequence showed 98.11% maximum identity with Theileria cf. sinensis and 97.99% identity with Theileria sinensis. Phylogenetically, Theileria spp. clustered with the T. cf. sinensis and T. sinensis. In the case of Anaplasma spp., the 16S rDNA sequence showed 100% identity with Anaplasma capra and phylogenetically clustered with the A. capra. PCR-based DNA detection targeting the amplification of groEL and flaB sequences of Coxiella spp. and Borrelia spp., respectively, was unsuccessful. This is the first phylogenetic report based on cox1 and new locality records of I. kashmiricus, and the associated T. sinensis-like and A. capra. Significant tick surveillance studies are needed in order to determine the epidemiology of Ixodes ticks and their associated pathogens.

Genomic Characteristics of Emerging Intraerythrocytic Anaplasma capra and High Prevalence in Goats, China

Anaplasma capra is an emerging tickborne human pathogen initially recognized in China in 2015; it has been reported in ticks and in a wide range of domestic and wild animals worldwide. We describe whole-genome sequences of 2 A. capra strains from metagenomic sequencing of purified erythrocytes from infected goats in China. The genome of A. capra was the smallest among members of the genus Anaplasma. The genomes of the 2 A. capra strains contained comparable G+C content and numbers of pseudogenes with intraerythrocytic Anaplasma species. The 2 A. capra strains had 54 unique genes. The prevalence of A. capra was high among goats in the 2 endemic areas. Phylogenetic analyses revealed that the A. capra strains detected in this study were basically classified into 2 subclusters with those previously detected in Asia. Our findings clarify details of the genomic characteristics of A. capra and shed light on its genetic diversity.

Tick Populations and Molecular Analysis of Anaplasma Species in Ticks from the Republic of Korea

The present study was performed to survey the dominant tick populations and molecularly determine the pathogenic agents of anaplasmosis in ticks from Gyeongsang, Republic of Korea. A total of 3825 questing ticks were collected by the flagging method from 12 sites near animal farms in Gyeongsang from March to October 2021. A molecular genomic study was performed with ticks stored in 70% ethanol to detect Anaplasma genes by the previously described method. The monthly incidence of ticks varied by developmental stages, i.e., nymphs, adults, and larvae, and each of their populations peaked in May, March, and October, respectively. The predominant tick species were Haemaphysalis longicornis, Haemaphysalis sp., Haemaphysalis flava, Ixodes nipponensis, and Amblyomma testudinarium in order. To determine the Anaplasma infection rate, collected ticks were pooled into 395 groups. The minimum infection rate (MIR) of Anaplasma was 0.7% (27 pools). That of A. phagocytophilum was highest (23 pools, MIR 0.6%), followed by A. phagocytophilum-like Anaplasma spp. clade B (2 pools, MIR 0.1%), A. bovis (1 pool, MIR 0.1%), and A. capra (1 pool, MIR 0.1%), respectively. In this study, five species of ticks, including unidentified Haemaphysalis species, were collected in 12 survey sites in Gyeongsang, but their prevalence was somewhat different according to the tick species and survey sites. Further, the incidence rate (6.8%) of 4 Anaplasma spp. was not as high in tick pools. However, the results of this study may offer a basis for future epidemiological research and risk assessment of tick-borne diseases.

Presence of Anaplasma spp. and Their Associated Antibodies in the Swedish Goat Population

Anaplasmosis is a tick-borne disease that has a severe impact on livestock production and welfare. The aim of this pilot study was to investigate the presence of Anaplasma spp. and associated antibodies in a subset of the Swedish goat population. In 2020, six goat herds located in different parts of Sweden were visited and whole blood and serum samples were collected. The whole blood samples (n = 40) were analysed for the presence of Anaplasma phagocytophilum, A. ovis and A. capra using quantitative and conventional polymerase chain reaction (PCR). The serum samples (n = 59) were analysed for the presence of antibodies to Anaplasma spp. using a commercial competitive enzyme-linked immunosorbent assay, and the same analysis was carried out on additional serum samples previously collected in 2018, 2019 and 2020 (n = 166). One goat (2.5%) tested positive for the presence of A. phagocytophilum genetic material, while the seropositivity rate ranged from 20 to 71%, depending on the surveyed year and area. These results indicate widespread exposure to Anaplasma spp. in the Swedish goat population. To inform future risk assessments and control efforts, further research is warranted to determine the prevalence of anaplasmosis and its impact on goat farming in Sweden.

Rickettsia sp. and Anaplasma spp. in Haemaphysalis longicornis from Shandong province of China, with evidence of a novel species "Candidatus Anaplasma Shandongensis"

Haemaphysalis longicornis is one of the most dominant and widespread tick species in China. This species mainly infests wild animals and occasionally attacks humans, and has been associated with the transmission of a variety of zoonotic pathogens including spotted fever group Rickettsia (SFGR), severe fever with thrombocytopenia syndrome virus (SFTSV), Anaplasma phagocytophilum, Babesia spp. and Theileria spp.. Although there are increasing reports of various pathogens associated with H. longicornis, some neglected pathogens in certain areas still need to be studied. In this study, a total of 171 H. longicornis ticks were collected from goats in three locations of Shandong Province, Eastern China (Zibo, Linyi, and Qingdao cities), and subsequently screened for the presence of Rickettsia, Anaplasma, and Ehrlichia bacteria. A total of four bacterial species were identified and characterized. "Candidatus Rickettsia jingxinensis" was detected in one tick specimen from Zibo city. Of 98 ticks from Linyi city, 63.27% (62/98) were tested positive for Anaplasma capra and 5.10% (5/98) were positive for Anaplasma bovis. Interestingly, a novel Anaplasma species was detected and characterized in one tick specimen from Zibo and one other from Linyi, respectively. Genetic and phylogenetic analysis based on the 16S, gltA, groEL, and msp4 genes indicated that it was divergent from all known Anaplasma species but mostly related to A. phagocytophilum and "Cadidatus Anaplasma boleense". Based on where it was first detected, we named it "Candidatus Anaplasma shandongensis".

Buffaloes as new hosts for Anaplasma capra: Molecular prevalence and phylogeny based on gtlA, groEL, and 16S rRNA genes

Anaplasma capra is a tick-borne pathogen that was discovered for the first time in goats in China in 2012. The studies carried out from the first detection in China to the present have revealed the presence of this species in eight countries including Angola, France, Iranian, South Korea, Kyrgyzstan, Malaysia, Spain, and Türkiye in three continents (Africa, Asia, and Europe). It has also been determined that humans, sheep, cattle, dog, and wild animals are the hosts of A. capra. It was investigated whether water buffaloes were the host of A. capra using nested-PCR and DNA sequencing in this study. The prevalence of A. capra in Turkish water buffalo herds was investigated and phylogenetic analyzes were performed on the basis of gltA, groEL, and 16S rRNA genes. A total of 364 water buffalo blood samples were examined in terms of A. capra using gltA gene species-specific nested-PCR. A. capra were detected in 52 of 364 (14.28%) blood samples. There was no statistically significant difference between the prevalence, gender, and age parameters. The gltA, groEL, and 16S rRNA genes in randomly selected three positive samples were sequenced. A. capra isolates obtained from water buffaloes in this study shared 85.20-100%(gltA), 89.84-100%(groEL), and 99.82-100%(16S rRNA) nucleotide similarity with A.capra isolates present in GeneBank. Phylogenetic analyses of gtlA and groEL genes revealed that A. capra divided in two different genogroups. In conclusion, this study revealed that water buffalo is a new host of A. capra. However, comprehensive studies are needed to determine the pathogenicity, vectors, and biological properties of A. capra in this new host.

The first molecular detection of Anaplasma capra in domestic ruminants in the central part of Turkey, with genetic diversity and genotyping of Anaplasma capra

Tick-borne diseases have been an increasing threat to human and animal health all over the world. Anaplasmosis is one of the emerging tick-borne diseases and has zoonotic potential. A new novel species, which was detected in China in 2010-2012 and provisionally named Anaplasma capra in 2015, causes zoonotic infections and infects many different animal species. In this study, we investigated the presence of A. capra in domestic ruminants from Turkey. A total of 468 blood samples (cattle, sheep, and goat) were examined by the gltA gene-specific nested polymerase chain reaction, revealing the presence of A. capra in six samples (1.28%): one of them from cattle (0.41%) and the other five from sheep (3.22%). According to DNA sequences results of the gltA gene, A. capra isolates identified in the present study were shown high nucleotide similarity with A. capra isolates detected from different hosts. However, the nucleotide differences were detected in the same nucleotide positions between A. capra isolates. For this reason, we thought that at least two different A. capra genotypes could be circulating in the world. As a result, it is seen that A. capra, which was determined to be a new species with zoonotic potential, was revealed in European and Asian countries and in different hosts. In order to raise awareness about human anaplasmosis infections, it is important to reveal the prevalence of the species in the world. The emergence of A. capra in Turkey reveals the need for a re-evaluation of the human and animal health risk analysis in terms of anaplasmosis.

Ehrlichia chaffeensis and Four Anaplasma Species With Veterinary and Public Health Significance Identified in Tibetan Sheep (Ovis aries) and Yaks (Bos grunniens) in Qinghai, China

Tick-borne diseases (TBDs) can cause serious economic losses and are very important to animal and public health. To date, research on TBDs has been limited in Qinghai-Tibet Plateau, China. This epidemiological investigation was conducted to evaluate the distribution and risk factors of Anaplasma spp. and Ehrlichia chaffeensis in livestock in Qinghai. A total of 566 blood samples, including 330 yaks (Bos grunniens) and 236 Tibetan sheep (Ovis aries) were screened. Results showed that A. bovis (33.3%, 110/330) and A. phagocytophilum (29.4%, 97/330) were most prevalent in yaks, followed by A. ovis (1.2%, 4/330), A. capra (0.6%, 2/330), and E. chaffeensis (0.6%, 2/330). While A. ovis (80.9%, 191/236) and A. bovis (5.1%, 12/236) infection was identified in Tibetan sheep. To our knowledge, it is the first time that A. capra and E. chaffeensis have been detected in yaks in China. Apart from that, we also found that co-infection of A. bovis and A. phagocytophilum is common in yaks (28.2%, 93/330). For triple co-infection, two yaks were infected with A. bovis, A. phagocytophilum, and A. capra, and two yaks were infected with A. bovis, A. phagocytophilum, and E. chaffeensis. Risk analysis shows that infection with A. bovis, A. phagocytophilum, and A. ovis was related to region and altitude. This study provides new data on the prevalence of Anaplasma spp. and E. chaffeensis in Qinghai, China, which may help to develop new strategies for active responding to these pathogens.

Diversity of Anaplasma species and importance of mixed infections in roe deer from Spain

Although wildlife can act as reservoirs of some Anaplasma species, studies on the presence and distribution of Anaplasma spp. in wild cervids are mainly limited and focused on zoonotic species. In order to identify the Anaplasma species in roe deer from Spain and to detect co-infections, 224 spleen samples were tested for Anaplasma spp. using a commercial qPCR; positive samples were further characterized using generic 16S rRNA primers and species-specific primers targeting the msp2 and groEL genes. Anaplasma DNA was detected in the 50.9% of samples, and four Anaplasma species were identified. Anaplasma phagocytophilum (43.8%) was predominant, followed by Anaplasma bovis (13.8%), Anaplasma capra (5.8%) and Anaplasma ovis (2.2%). In addition, strains similar to Anaplasma platys were found in nine animals. Most positive roe deer (71.9%) were infected with a single Anaplasma species, whereas co-infections with two (19.3%) or three (8.8%) Anaplasma species were also found. This study confirms the widespread occurrence of Anaplasma spp. in roe deer from Spain, being the first report of A. platys-like strains and A. capra in this cervid; it is also the first report of A. capra in Spain. The detection of Anaplasma species pathogenic for humans and/or domestic animals in roe deer suggests that this cervid may play a role in the sylvatic cycle of these bacteria contributing to the appearance of clinical anaplasmosis cases. In addition, co-infections are common in roe deer revealing that Anaplasma species specific PCR assays are essential for a reliable identification as well as for determining their real prevalence.

The first detection of Anaplasma capra, an emerging zoonotic Anaplasma sp., in erythrocytes

An emerging infectious disease caused by “Anaplasma capra” was reported in a 2015 survey of 477 hospital patients with a tick-bite history in China. However, the morphological characteristics and parasitic location of this pathogen are still unclear, and the pathogen has not been officially classified as a member of the genus Anaplasma. Anaplasma capra-positive blood samples were collected, blood cells separated, and DNA of whole blood cells, erythrocytes, and leukocytes extracted. Multiplex PCR detection assay was used to detect whole blood cell, erythrocytes and leukocytes, DNA samples, and PCR identification, nucleic acid sequencing, and phylogenetic analyses based on A. capra groEL, 16S rRNA, gltA, and msp4 genes. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Wright–Giemsa staining, chromogenic in situ hybridization (CISH), immunocytochemistry, and indirect immunofluorescence assay (IFA) were used to identify the location and morphological characteristics of A. capra. Multiple gene loci results demonstrated that erythrocyte DNA samples were A. capra-positive, while leukocyte DNA samples were A. capra-negative. Phylogenetic analysis showed that A. capra is in the same clade with the A. capra sequence reported previously. SEM and TEM showed one or more pathogens internally or on the outer surface of erythrocytes. Giemsa staining, CISH, immunocytochemistry, and IFA indicated that erythrocytes were A. capra-positive. This study is the first to identify the novel zoonotic tick-borne Anaplasma sp., “Anaplasma capra,” in host erythrocytes. Based on our results, we suggest revision of Genus Anaplasma and formally name “A. capra” as Anaplasma capra sp. nov.

Genetic characterization and phylogenetic of Anaplasma capra in Persian onagers (Equus hemionus onager)

Anaplasma spp. are among the most recognized arthropod-borne infectious agents. Although the novel A. capra has been isolated from wildlife, livestock, and hard ticks from many parts of the world, there is no report regarding the identification of this pathogen from equines and little is known about the epidemiology of A. capra in Equidae. In this study, A. capra was identified in two out of ten blood specimens of wild onagers (Equus hemionus onager) during a routine health check-up in Semnan, Iran by light microscopy and molecular analyses while other pathogens were not detected. First, inclusions on RBC's were observed in two blood smears by light microscopy. Then, the blood specimens of both animals were analyzed by realtime-PCR for Anaplasma, Ehrlichia, and Theileria infections. A 1400 bp sequence of 16S rRNA belonging to Anaplasmataceae and 874 bp fragment for groEL gene for A. capra were amplified in Anaplasma positive samples and sequenced. Preliminary BLAST analysis of sequenced fragments showed high homology to A. capra strains in GenBank database. Finally, nested PCR and restriction enzyme fragment length polymorphism techniques confirmed the pathogen as A. capra. To the best of our knowledge, this study has reported the occurrence of A. capra in wild onagers for the first time and suggests that equines could be infected with this pathogen and act as reservoirs for A. capra.

The Novel Zoonotic Pathogen, Anaplasma capra, Infects Human Erythrocytes, HL-60, and TF-1 Cells In Vitro

Anaplasma capra, a species of the family Anaplasmataceae, is zoonotic tick-borne obligate intracellular bacteria. There have been no reports of human infection with this pathogen since 2015. Therefore, the zoonotic characteristics of A. capra need to be further studied. To verify the ability of A. capra to infect human cells, A. capra were inoculated in human erythrocytes, HL-60, and TF-1 cell lines in vitro. Cell smears were taken after inoculation, using Giemsa staining, transmission electron microscope (TEM), chromogenic in situ hybridization and immunocytochemistry for detection. In the Giemsa staining, many dark colored corpuscles or purple granules were seen in the inoculated erythrocytes, HL-60, and TF-1 cells. The results of chromogenic in situ hybridization show that there were brown precipitates on the surface of most erythrocytes. Immunocytochemistry results show many dark brown vacuolar structures or corpuscles in the cytoplasm of erythrocytes, HL-60, and TF-1 cell lines. The A. capra morulae were seen in the cytoplasm of both HL-60 and TF-1 in TEM, and their diameter was about 295–518 nm. Both dense-cored (DC) and reticulate cell (RC) form morulae could be seen. This study confirmed the ability of A. capra to infect human erythrocytes, HL-60, and TF-1. This study is of profound significance in further verifying the zoonotic characteristics of the pathogen and for establishing an in vitro cultivation model.

Co-Infection with Anaplasma Species and Novel Genetic Variants Detected in Cattle and Goats in the Republic of Korea

Anaplasmosis, a tick-borne disease with multiple reservoirs, has been evolving in its pathogenesis, increasing domestic ruminants susceptibility to simultaneous infections with multiple pathogens. However, there is limited information regarding anaplasmosis in domestic ruminants in the Republic of Korea (ROK). We aimed to evaluate the role of Korean cattle and goats in Anaplasma infection maintenance. Polymerase chain reaction was performed to investigate the prevalence and genetic diversity of Anaplasma spp. from 686 whole blood samples collected from different ROK provinces. Anaplasma infection was mostly caused by A. phagocytophilum (21.1%) in cattle, and A. bovis (7.3%) in goats. Co-infection cases were found in cattle: A. bovis and A. phagocytophilum (16.7%), and in goats: A. bovis and A. capra (1.0%). Notably, a triple co-infection with A. bovis, A. phagocytophilum, and A. capra was found in one cow. Phylogenetic analysis revealed novel variants of the A. phagocytophilum 16S rRNA and A. capra gltA genes. This research contributes to the ratification of cattle as a potential reservoir of A. capra and demonstrates Anaplasma co-infection types in Korean domestic ruminants. As anaplasmosis is a zoonotic disease, our study could be crucial in making important decisions for public health.

Novel Anaplasma Variants in Small Ruminants From Central China

Anaplasma capra is an emerging zoonotic pathogen that pose a risk to the health of human and veterinary animal. Numerous variants in a variety of domestic and wild animals had been reported since its discovery and confirmation in humans in 2015 and its first detection from goat blood during 2012-2013. In order to find out more A. capra variants data of A. capra in central China, 16S rRNA, gltA, groEL, and msp4 genes of this pathogen were amplified from sheep and goat samples collected during 2011-2015 and phylogenetic analysis of these sequences were conducted. The results of 16S rRNA and gltA manifested that partial sequences obtained in this study were 100% identical with A. capra isolates, while phylogenetic analysis results of groEL and msp4 showed that the obtained sequences were independent with all other Anaplasmas, formed separate branches on the evolutionary trees. What needed to be emphasized was that the 16S rRNA and gltA gene sequences of X51 (KX505302 and KX450269), a sample from Shandong in 2011, were found to be 100% identical with A. capra. Therefore, we could speculate that the occurrence of A. capra may be earlier than its first discovery and report. And the A. capra isolates in central China were novel variants which were different from known genotypes.

Identification of Zoonotic Tick-Borne Pathogens from Korean Water Deer (Hydropotes inermis argyropus)

Korean water deer (Hydropotes inermis argyropus) are widespread in the Republic of Korea (ROK). Mostly, Korean water deer are essential hosts for maintaining ticks and tick-borne diseases (TBDs). Here, we investigated the prevalence of tick-borne pathogens (TBPs) among rescued Korean water deer. Anaplasma phagocytophilum (21.4%, 6/28), Anaplasma capra (14.3%, 4/28), Babesia capreoli (3.6%, 1/28), and Coxiella burnetii (3.6%, 1/28) were detected, but Borrelia burgdorferi, Ehrlichia, Rickettsia, and Theileria infections were not found. A. phagocytophilum was the most commonly detected pathogen, and co-infection with A. capra and B. capreoli was also noted in one Korean water deer. To our knowledge, this is the first article of B. capreoli infection in Korean water deer in the ROK. The infecting isolate of A. phagocytophilum was genetically characterized by 16S ribosomal RNA (rRNA) gene and ankyrin-related protein (ankA) gene. Although the 16S rRNA gene alone may not be informative enough to delineate distinct host species, ankA-based phylogeny revealed a high identity of Korean water deer sequences with those of the causative agent of human granulocytic anaplasmosis. A. capra was detected by using citrate synthase gene (gltA), heat-shock protein (groEL), and major surface protein 4 (msp4) genes. Phylogenetic tree based on these gene markers revealed that there were at least two distinct variants within A. capra circulating in the ROK. One variant originated from different hosts including humans, ticks, goats, and sheep, whereas the other variant was reported recently in Korean water deer in the ROK. Consequently, these sequences were identified to belong to a zoonotic species. Sequencing analysis of the 18S rRNA gene revealed that our isolate belonged to B. capreoli and was distinct from Babesia divergens and Babesia venatorum. Moreover, our isolate showed 92.2% homology with B. capreoli sequences, indicating that these differences may be attributed to the different tick species that transmit B. capreoli or to different host species. Genotyping and phylogenetic analysis of C. burnetii based on 16S rRNA and IS1111 genes revealed that our isolate was grouped with several strains of C. burnetii and was genetically distant from Coxiella-like bacteria isolates. The present results highlight that Korean water deer act as potential reservoir hosts for zoonotic TBPs, and thus play an important role in the transmission of TBDs in humans, animals, and livestock.

A Multiplex PCR Detection Assay for the Identification of Clinically Relevant Anaplasma Species in Field Blood Samples

The genus Anaplasma (Rickettsiales: Anaplasmataceae), which includes the species Anaplasma capra, Anaplasma bovis, Anaplasma ovis, and Anaplasma phagocytophilum, is responsible for a wide variety of infections in both human and veterinary health worldwide. Multiple infections with these four Anaplasma pathogens have been reported in many cases. We introduce a novel multiplex PCR for the simultaneous detection of A. capra, A. bovis, A. ovis, and A. phagocytophilum, based on species-specific primers against the groEL (A. capra and A. bovis), msp4 (A. ovis), and 16S rRNA (A. phagocytophilum) genes. To verify the specificity of the PCR reactions, we evaluated four sets of primers to analyze samples containing different blood pathogens. The sensitivity of the multiplex PCR was evaluated by amplifying 10-fold dilutions of total genomic DNA extracted from sheep blood infected with A. capra, A. bovis, A. ovis, or A. phagocytophilum. The reproducibility of the assay was evaluated by testing 10-fold dilutions of total genomic DNA extracted from sheep blood infected with these pathogens from 10⁰ to 10^–3 ng/μL per reaction in triplicate on three different days. A total of 175 field blood DNA samples were used to evaluate the reproducibility of multiplex PCR compared with the simplex PCRs. PCR primers used in this study were confirmed to be 100% species-specific using blood pathogens previously identified by other methods. The lower limit of detection of the multiplex PCR with good repeatability enabled the detection of A. capra, A. bovis, A. ovis and A. phagocytophilum at concentrations of 3 × 10^–5, 5 × 10^–7, 2 × 10^–5, and 7 × 10^–7 ng/μL, respectively. There was no significant difference between conventional and multiplex PCR protocols used to detect the four Anaplasma species (P > 0.05). The results of the multiplex PCR revealed that the A. capra groEL gene, the A. bovis groEL gene, the A. ovis msp4 gene, and the A. phagocytophilum 16S rRNA gene were reliable target genes for species identification in clinical isolates, being specific for each of the four target Anaplasma species. Our study provides an effective, sensitive, specific, and accurate tool for the rapid differential clinical diagnosis and epidemiological surveillance of Anaplasma pathogens in sheep and goats.

Dogs as New Hosts for the Emerging Zoonotic Pathogen Anaplasma capra in China

Anaplasma capra is an emerging zoonotic tick-borne pathogen with a broad host range, including many mammals. Dogs have close physical interactions with humans and regular contact with the external environment. Moreover, they have been previously reported to be hosts of Anaplasma phagocytophilum, A. platys, A. ovis, and A. bovis. To confirm whether dogs are also hosts of A. capra, pathogen DNA was extracted from blood samples of 521 dogs, followed by PCR amplification of the citrate synthase (gltA) gene, heat shock protein (groEL) gene, and major surface protein 4 (msp4) gene of the A. capra. A total of 12.1% (63/521) of blood samples were shown to be A. capra-positive by PCR screening. No significant differences were observed between genders (P = 0.578) or types (P = 0.154) of dogs with A. capra infections. However, significantly higher A. capra infections occurred in dogs with regular contact with vegetation (P = 0.002), those aged over 10 years (P = 0.040), and during the summer season (P = 0.006). Phylogenetic analysis based on gltA, groEL, and msp4 sequences demonstrated that the isolates obtained in this study were clustered within the A. capra clade, and were distinct from other Anaplasma species. In conclusion, dogs were shown to be a host of the human pathogenic A. capra. Considering the affinity between dogs and humans and the zoonotic tick-borne nature of A. capra, dogs should be carefully monitored for the presence of A. capra.

Duplex TaqMan real-time PCR assay for simultaneous detection and quantification of Anaplasma capra and Anaplasma phagocytophilum infection

Anaplasma capra and A. phagocytophilum, two species of the family Anaplasmataceae, are zoonotic tick-borne obligate intracellular bacteria affecting wild and domestic ruminants, dogs, cats, horses and humans. A. capra and A. phagocytophilum infections have been steadily increasing in both number and geographic distribution, and the accurate diagnosis of these infections is challenging. This study aimed to develop a rapid, sensitive and reliable duplex real-time PCR assay for the specific detection and differentiation of these Anaplasma species. We designed primers and probes against the conserved regions of A. capra groEL and A. phagocytophilum 16S rRNA genes. A range of PCR-related parameters were evaluated such as the dosage of primers and probes, and annealing temperature. The specificity, sensitivity and repeatability of this assay were evaluated. Assay performance was further evaluated using samples collected from 124 goats in four regions of Henan, China. This set of samples was also tested using conventional PCR under conditions previously described. The developed duplex real-time PCR assay allowed the simultaneous detection of A. capra and A. phagocytophilum in a reasonably short time at levels as small as 10² copies/μL, respectively, with optimal specificity and reproducibility. In addition, this duplex real-time PCR assay is the first DNA-based method designed to detect A. capra and A. phagocytophilum, and will be valuable for timely diagnosis and treatment of these infections.

Molecular Detection and Phylogenetic Analysis of Anaplasma spp. in Korean Native Goats from Ulsan Metropolitan City, Korea

Background: Tick-borne diseases (TBDs) can be fatal to humans as well as to animals causing severe economic losses globally to livestock industries. Many countries conduct regular surveillance of TBDs in livestock. Serological and molecular surveillance of TBDs in livestock and humans was carried out in the Republic of Korea. However, there are not a lot of data on analyses of anaplasmosis in Korean native goats and the correlation with rearing methods and seasons. Methods: In this study, goats in Ulsan city were tested for anaplasmosis by PCR and 16S rRNA sequencing. A total of 452 goat blood samples were collected from 20 farms in 2016. The goat farms in Ulsan city had three different types of rearing methods: conventional, confined, and mixed grazing-confined. Results: Forty-nine of the 452 goats (10.8%) were anaplasmosis positive. Sequence analysis of the PCR products from these 49 goats revealed that 39 of 452 goats (8.6%) were Anaplasma bovis positive, and 10 of 452 goats (2.2%) were infected with Anaplasma capra. The highest outbreaks of anaplasmosis occurred in mixed grazing-confined type of farms (27.1%, 33/122) (χ² = 60.72, df = 2, p < 0.05), but there was no significant difference in the occurrence of anaplasmosis between spring, summer, and fall seasons. Conclusions: This study was the first detection of A. bovis in Korean native goats and its relationship with rearing methods and seasons. These findings suggested that Korean native goats were highly exposed to Anaplasma spp. during summers when the tick population is the highest and in farms employing mixed grazing-confined rearing methods.

Novel variants of the newly emerged Anaplasma capra from Korean water deer (Hydropotes inermis argyropus) in South Korea

BACKGROUND

Anaplasma spp. are tick-borne Gram-negative obligate intracellular bacteria that infect humans and a wide range of animals. Anaplasma capra has emerged as a human pathogen; however, little is known about the occurrence and genetic identity of this agent in wildlife. The present study aimed to determine the infection rate and genetic profile of this pathogen in wild animals in the Republic of Korea.

METHODS

A total of 253 blood samples [198 from Korean water deer (Hydropotes inermis argyropus), 53 from raccoon dogs (Nyctereutes procyonoides) and one sample each from a leopard cat (Prionailurus bengalensis) and a roe deer (Capreolus pygargus)] were collected at Chungbuk Wildlife Center during the period 2015-2018. Genomic DNA was extracted from the samples and screened for presence of Anaplasma species by PCR/sequence analysis of 429 bp of the 16S rRNA gene marker. Anaplasma capra-positive isolates were genetically profiled by amplification of a longer fragment of 16S rRNA (rrs) as well as partial sequences of citrate synthase (gltA), heat-shock protein (groEL), major surface protein 2 (msp2) and major surface protein 4 (msp4). Generated sequences of each gene marker were aligned with homologous sequences in the database and phylogenetically analyzed.

RESULTS

Anaplasma capra was detected in blood samples derived from Korean water deer, whereas samples from other animal species were negative. The overall infection rate in tested samples was 13.8% (35/253) and in the water deer the rate was 17.8% (35/198), distributed along the study period from 2015 to 2018. Genetic profiling and a phylogenetic analysis based on analyzed gene markers revealed the occurrence of two distinct strains, clustered in a single clade with counterpart sequences of A. capra in the database.

CONCLUSIONS

Anaplasma capra infection were detected in Korean water deer in the Republic of Korea, providing insight into the role of wildlife as a potential reservoir for animal and human anaplasmosis. However, further work is needed in order to evaluate the role of Korean water deer as a host/reservoir host of A. capra.

Molecular identification and characterization of Anaplasma capra and Anaplasma platys-like in Rhipicephalus microplus in Ankang, Northwest China

Background

Four species within Anaplasma genus are emerging zoonotic pathogens, which are transmitted by ticks and generate veterinary and public health concerns. Here, we performed a molecular survey of Anaplasma in Ankang, Northwest China.

Methods

Hard ticks were collected and identified using morphological and molecular methods. Human-pathogenic Anaplasma species were tested using nested polymerase chain reaction. The nearly complete rrs, gltA, and groEL genes sequences from revealed Anaplasma species were amplified and sequenced to determine their molecular characteristics and their phylogeny.

Results

All ticks collected in Ankang belonged to the Rhipicephalus microplus. Novel unclassified Anaplasma strains genetically related to A. platys and A. capra were detected in these ticks. Co-infection of these two organisms was also found. The novel unclassified Anaplasma strains identified in this study formed a distinct phylogenetic lineage based on the groEL gene and two lineages based on the gltA gene within A. platys and related strains group. The revealed A. capra strains identified in this study were most closely related to those detected in humans and other vertebrate animals.

Conclusion

We revealed the presence of A. capra, a novel human pathogens in R. microplus ticks in previously unrecognized endemic regions. We also detected a novel unclassified Anaplasma species genetically related to A. platys. The epidemiology of anaplasmosis caused by these two Anaplasma species in humans should be assessed in future studies.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4075-3) contains supplementary material, which is available to authorized users.

Differential identification of Anaplasma in cattle and potential of cattle to serve as reservoirs of Anaplasma capra, an emerging tick-borne zoonotic pathogen

Bovine anaplasmosis is a tick-borne, infectious, non-contagious disease caused by Anaplasma marginale, A. centrale, A. bovis, and zoonotic A. phagocytophilum. Recently, Anaplasma capra detected in goats was identified as a novel zoonotic pathogen. To determine whether A. capra can infect bovines, we used PCR to differentially diagnose Anaplasma spp. in 1219 South Korean cattle by performing multilocus gene typing and restriction fragment length polymorphism (RFLP). Nucleotide sequencing and phylogenetic analysis detected the 16S rRNA gene of A. bovis and four genes from A. capra in 12 (1.0%) and five (0.4%) cattle, respectively. Supplementary discrimination between A. bovis and A. capra was accomplished by RFLP. The 16S rRNA, msp4, groEL, and gltA genes of A. capra identified in this study had much lower degrees of identity to those in A. centrale and other Anaplasma spp. A. phagocytophilum was not detected in any of the tested cattle. Although the prevalence was low, this study suggests the potential of cattle to serve as reservoirs of A. capra. Thus, further studies are needed to clarify the pathogenesis of A. capra in cattle and its possible involvement in transmission to humans.

Detection and Phylogenetic Characterization of Anaplasma capra: An Emerging Pathogen in Sheep and Goats in China

Anaplasma capra is an emerging pathogen, which can infect ruminants and humans. This study was conducted to determine the occurrence of A. capra in the blood samples of sheep and goats in China. Using nested polymerase chain reaction (nested-PCR) targeting the gltA gene and conventional PCR targeting the heat shock protein (groEL) gene and the major surface protein4 gene (msp4), A. capra was detected in 129 (8.9%) of 1453 sheep and goat blood samples. The positive rate was higher in goats (9.4%, 89/943) than in sheep (7.8%, 40/510) (χ² = 1.04, p > 0.05, df = 1). For sheep, A. capra was found in 17 sites from 2 provinces. The prevalence was 28.6% in sheep from Liaoning province, which was higher than in Henan Province (7.3%). For goats, A. capra was detected in 35 sites from 7 provinces. The prevalence varied from 0 to 19.4% in the goat sites examined. The prevalence rates were 19.4, 19.3, 10, 8.8, 6.8, 1.8, and 0% in goats from Guizhou province, Henan Province, Inner Mongolia Autonomous Region, Shanxi Province, Xinjiang Uygur Autonomous Region, Yunnan province, and Gansu province, respectively. Based on the analysis of the A. capra citrate synthase gene (gltA), two variants were identified. Variant I showed a high sequence similarity to the A. capra, which were previously reported in sheep, goats, Ixodes persulcatus, Haemaphysalis longicornis, Haemaphysalis qinghaiensis, and humans. Variant II was only found in Luoyang, Anyang, and Sanmengxia, of Henan province. To our knowledge, this is the first detection of this variant of A. capra in sheep and goat blood in China. Phylogenetic analysis based on groEL and msp4 genes showed that the Anaplasma sp. sequences clustered independently from A. capra and other Anaplasma species with high bootstrap values. We found A. capra DNA in sheep and goats in China, providing evidence that sheep and goats can be infected by A. capra. We also found that this zoonotic pathogen is widely distributed in China. This study provides information for assessing the public health risks for human anaplasmosis.

Occurrence of four Anaplasma species with veterinary and public health significance in sheep, northwestern China

The members of the genus Anaplasma are important tick-borne rickettsial bacteria of veterinary and public health significance. Domestic ruminants are important reservoir hosts for several Anaplasma species. In this study, the occurrence of Anaplasma spp. was investigated by PCR in domestic small ruminants from Gansu, northwestern China. The results showed a high prevalence of Anaplasma spp. (46.2%, 201/435) in sheep. The average infection rates were 5.7%, 24.4%, 28.0% and 18.2% for A. ovis, A. bovis, A. phagocytophilum and A. capra, respectively. Coinfection of different Anaplasma species occurred in 96 (22.1%) sheep. The infections of Anaplasma species in sheep were confirmed by sequencing of msp4, 16S rRNA and gltA genes. Sequence analysis revealed a novel A. capra genotype in sheep that was distinct from the isolates identified from patients in northeastern China. This study gives the first insight of presence of four distinct Anaplasma species with veterinary and medical significance in sheep in northwestern China.

A novel zoonotic Anaplasma species is prevalent in small ruminants: potential public health implications

Background

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.

Methods

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).

Results

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.

Conclusions

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.

Prevalence of Severe Febrile and Thrombocytopenic Syndrome Virus, Anaplasma spp. and Babesia microti in Hard Ticks (Acari: Ixodidae) from Jiaodong Peninsula, Shandong Province

The presence of tick-borne pathogens and their possible coinfections were evaluated among host-seeking ticks in seven cities from Jiaodong peninsula, Shandong Province, with specific PCR or reverse transcription-PCR tests. Among 2107 ticks collected, four species of three genera were identified with Haemaphysalis longicornis as predominant species, and total of 63 H. longicornis and 10 Rhicephalus microplus were confirmed infected with tick-borne pathogens. These pathogens were consequently identified as severe febrile and thrombocytopenic syndrome virus (SFTSV), Anaplasma capra, Anaplasma phygocytophilum, and Babesia microti, respectively, with high phylogenetic scores on some fragments of species-specific genes. The infection rates of the pathogens in H. longicornis were presented as 1.03%, 0.84%, 0.58%, and 1.66%, respectively, close related to its field density and clump distribution pattern. Furthermore, coinfection of A. capra and SFTSV was also discovered from two female H. longicornis in Pingdu city. These results indicated that the potential human pathogens other than severe febrile and thrombocytopenic syndrome might be transmitted by hard ticks separately or in combination, and more reliable differential diagnosis, proper administrations, rational prevention, and control measures should be developed with the support of precision laboratory tests.