Molecular Detection of Tick-BorneRickettsialesin Goats and Sheep from Southeastern China

Genomic characters of Anaplasma bovis and genetic diversity in China

The emergence of Anaplasma bovis or A. bovis-like infection in humans from China and the United States of America has raised concern about the public health importance of this pathogen. Although A. bovis has been detected in a wide range of ticks and mammals in the world, no genome of the pathogen is available up to now, which has prohibited us from better understanding the genetic basis for its pathogenicity. Here we describe an A. bovis genome from metagenomic sequencing of an infected goat in China. Anaplasma bovis had the smallest genome of the genus Anaplasma, and relatively lower GC content. Phylogenetic analysis of single-copy orthologue sequence showed that A. bovis was closely related to A. platys and A. phagocytophilum, but relatively far from intraerythrocytic Anaplasma species. Anaplasma bovis had 116 unique orthogroups and lacked 51 orthogroups in comparison to other Anaplasma species. The virulence factors of A. bovis were significantly less than those of A. phagocytophilum, suggesting less pathogenicity of A. bovis. When tested by specific PCR assays, A. bovis was detected in 23 of 29 goats, with an infection rate up to 79.3% (95% CI: 64.6% ∼94.1%). The phylogenetic analyses based on partial 16S rRNA, gltA and groEL genes indicated that A. bovis had high genetic diversity. The findings of this study lay a foundation for further understanding of the biological characteristics and genetic diversity of A. bovis, and will facilitate the formulation of prevention and control strategies.

Epidemiological Investigation of Tick-Borne Bacterial Pathogens in Domestic Animals from the Qinghai-Tibetan Plateau Area, China

The Qinghai-Tibetan Plateau area (QTPA) features a unique environment that has witnessed the selective breeding of diverse breeds of domestic livestock exhibiting remarkable adaptability. Nevertheless, Anaplasma spp., Rickettsia spp., Coxiella spp., and Borrelia spp. represent tick-borne bacterial pathogens that pose a global threat and have substantial impacts on both human and animal health, as well as on the economy of animal husbandry within the Qinghai-Tibetan plateau area. In this study, a total of 428 samples were systematically collected from 20 distinct areas within the Qinghai Plateau. The samples included 62 ticks and 366 blood samples obtained from diverse animal species to detect the presence of Anaplasma spp., Rickettsia spp., Coxiella spp., and Borrelia spp. The prevalence of infection in this study was determined as follows: Anaplasma bovis accounted for 16.4% (70/428), A. capra for 4.7% (20/428), A. ovis for 5.8% (25/428), Borrelia burgdorferi sensu lato for 6.3% (27/428), Coxiella burnetii for 0.7% (3/428), and Rickettsia spp. for 0.5% (2/428). Notably, no cases of A. marginale and A. phagocytophilum infections were observed in this study. The findings revealed an elevated presence of these pathogens in Tibetan sheep and goats, with no infections detected in yaks, Bactrian camels, donkeys, and horses. To the best of our knowledge, this study represents the first investigation of tick-borne bacterial pathogens infecting goats, cattle, horses, and donkeys within the Qinghai Plateau of the Qinghai-Tibetan Plateau area. Consequently, our findings contribute valuable insights into the distribution and genetic diversity of Anaplasma spp., Rickettsia spp., Coxiella spp., and Borrelia spp. within China.

Molecular surveillance and genetic diversity of Anaplasma spp. in cattle (Bos taurus) and goat (Capra aegagrus hircus) from Hainan island/province, China

Anaplasmosis is a highly prevalent tick-borne intracellular bacterial disease that affects various host species globally, particularly ruminants in tropical and subtropical regions. However, information regarding the distribution and epidemiology of anaplasmosis in small and large ruminants on Hainan Isalnd is limited. To address this knowledge gap, the present study aimed to assess the occurrence of Anaplasma spp. infections in goats (N = 731) and cattle (N = 176) blood samples using nested PCR and conventional PCR based assays. The results revealed an overall prevalence of 30.1% in goats and 14.8% in cattle. The infection rates of A. bovis, A. phagocytophilum, A. ovis and A. capra in goat samples were 22.7%, 13.8%, 2.0% and 3.4%, respectively, while the infection rates of A. bovis, A. phagocytophilum and A. marginale in cattle samples were 11.4%, 6.3% and 5.7%, respectively. A. bovis exhibited the highest prevalence among the Anaplasma spp. in both goat and cattle samples. In addition, the most frequent co-infection was the one with A. phagocytophilum and A. bovis. It was found that the age, sex and feeding habits of cattle and goats were considered to be important risk factors. Evaluation of the risk factor relating to the rearing system showed that the infection rate for the free-range goats and cattle was significantly higher when compared with stall-feeding system.This study represents one of the largest investigations on the distribution, prevalence, and risk factors associated with Anaplasma infection in ruminants on Hainan Island, highlighting a higher circulation of the infection in the region than previously anticipated. Further reasesrch is necessary to investigate tick vectors, reservoir animals, and the zoonotic potential of the Anaplasma spp. in this endemic region of Hainan Island.

Circulation of four species of Anaplasmataceae bacteria in ticks in Harbin, northeastern China

Ticks play an important role in the evolution and transmission of Anaplasmataceae bacteria which are agents of emerging infectious diseases. In this study, a total of 1286 adult ticks belonging to five species were collected from cattle, goats, horses and vegetation in Harbin area, Heilongjiang province, northeastern China. The tick-borne Anaplasmataceae bacteria were identified by amplifying and sequencing the 16S rRNA (rrs) and heat shock protein-60 encoding (groEL) genes. The results showed that Ixodes persulcatus was dominant (38.8%, 499/1283) among the five tick species, and Anaplasmataceae bacteria were detected in all tick species with an overall prevalence of 7.4%. Four species of Anaplasmataceae bacteria (Anaplasma phagocytophilum, Anaplasma ovis, Anaplasma bovis, and "Candidatus Neoehrlichia mikurensis"), which are pathogenic to humans and/or animals, were identified from tick samples by phylogenetic analyzes of the rrs and groEL gene sequences. Interestingly, the cluster 1 strains were first identified in Asian, and a novel cluster was also detected in this study. These data revealed the genetic diversity of Anaplasmataceae bacteria circulating in ticks in Harbin area, highlighting the need to investigate these tick-borne pathogens and their risks to human and animal health.

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 epidemiological 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 presence. Phylogenetic analyses of these TBP sequences revealed the presence of Rickettsia japonica, Ehrlichia minasensis, 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.

The Scenario of Ticks and Tick-Borne Pathogens of Sheep on a Mediterranean Island

Ticks and transmitted pathogens constitute a major concern for livestock health/welfare and productivity for the Mediterranean region, often posing an important zoonotic threat. The aim of this study was to investigate the presence, infection intensity, and seasonality of ticks and tick-borne pathogens on the island of Lesvos in Greece, which was selected as a potential hotspot for their circulation. To this end, 101 sheep farms were visited over a tick activity season, and ticks, blood samples, and questionnaire data were collected. Ticks were identified by species, and DNA from both ticks and blood samples was further investigated using the polymerase chain reaction–reverse line blot (PCR–RLB) technique. In 72.3% of the farms, sheep were found to be infected by 9 ixodid species, with Rhipicephalus turanicus being the most common during the spring/early summer period. As regards tick-borne pathogens (TBPs), 84.9% of the animals were found to be infected with at least one pathogen, the most common being genera of Anaplasma and Theileria, alone or in co-infections. To further characterize the Anaplasma species found, selected samples were sequenced, revealing isolates of A. ovis, A. capra, A. marginale, and A. phagocytophilum. Of the 169 female R. turanicus ticks analyzed by PCR–RLB, 89.9% were harboring at least one TBP belonging to the genera Anaplasma, Ehrlichia, Babesia, Theileria, or Rickettsia. Overall, the data presented in this study revealed a high burden of ticks and TBPs in sheep, including zoonotic species, stressing the need for applying effective monitoring and control programs using a more holistic One Health approach.

Molecular Survey of Vector-Borne Pathogens in Ticks, Sheep Keds, and Domestic Animals from Ngawa, Southwest China

Vector-borne pathogens are mainly transmitted by blood-feeding arthropods such as ticks, mosquitoes, fleas, lice, mites, etc. They pose a significant threat to animal and human health due to their worldwide distribution. Although much work has been performed on these pathogens, some neglected areas and undiscovered pathogens are still to be further researched. In this study, ticks (Haemaphysalis qinghaiensis), sheep keds (Melophagus ovinus), and blood samples from yaks and goats were collected in Ngawa Tibetan and Qiang Autonomous Prefecture located on the eastern edge of the Qinghai–Tibet Plateau, Southwest China. Several vector-borne bacterial pathogens were screened and studied. Anaplasma bovis strains representing novel genotypes were detected in ticks (8.83%, 37/419), yak blood samples (45.71%, 64/140), and goat blood samples (58.93%, 33/56). Two spotted fever group (SFG) Rickettsiae, Candidatus Rickettsia jingxinensis, and a novel Rickettsia species named Candidatus Rickettsia hongyuanensis were identified in ticks. Another Rickettsia species closely related to the Rickettsia endosymbiont of Polydesmus complanatus was also detected in ticks. Furthermore, a Coxiella species was detected in ticks (3.34%, 14/419), keds (1.89%, 2/106), and yak blood (0.71%, 1/140). Interestingly, another Coxiella species and a Coxiella-like bacterium were detected in a tick and a goat blood sample, respectively. These results indicate the remarkable diversity of vector-borne pathogens circulating in this area. Further investigations on their pathogenicity to humans and domestic animals are still needed.

The Use and Limitations of the 16S rRNA Sequence for Species Classification of Anaplasma Samples

With the advent of cheaper, high-throughput sequencing technologies, the ability to survey biodiversity in previously unexplored niches and geographies has expanded massively. Within Anaplasma, a genus containing several intra-hematopoietic pathogens of medical and economic importance, at least 25 new species have been proposed since the last formal taxonomic organization. Given the obligate intracellular nature of these bacteria, none of these proposed species have been able to attain formal standing in the nomenclature per the International Code of Nomenclature of Prokaryotes rules. Many novel species’ proposals use sequence data obtained from targeted or metagenomic PCR studies of only a few genes, most commonly the 16S rRNA gene. We examined the utility of the 16S rRNA gene sequence for discriminating Anaplasma samples to the species level. We find that while the genetic diversity of the genus Anaplasma appears greater than appreciated in the last organization of the genus, caution must be used when attempting to resolve to a species descriptor from the 16S rRNA gene alone. Specifically, genomically distinct species have similar 16S rRNA gene sequences, especially when only partial amplicons of the 16S rRNA are used. Furthermore, we provide key bases that allow classification of the formally named species of Anaplasma.

Genetic diversity of Anaplasma bacteria: Twenty years later

The genus Anaplasma (family Anaplasmataceae, order Rickettsiales) includes obligate intracellular alphaproteobacteria that multiply within membrane-bound vacuoles and are transmitted by Ixodidae ticks to vertebrate hosts. Since the last reclassification of Anaplasmataceae twenty years ago, two new Anaplasma species have been identified. To date, the genus includes eight Anaplasma species (A. phagocytophilum, A. marginale, A. centrale, A. ovis, A. bovis, A. platys, A. odocoilei, and A. capra) and a large number of unclassified genovariants that cannot be assigned to known species. Members of the genus can cause infection in humans and a wide range of domestic animals with different degrees of severity. Long-term persistence which, in some cases, is manifested as cyclic bacteremia has been demonstrated for several Anaplasma species. Zoonotic potential has been shown for A. phagocytophilum, the agent of human granulocytic anaplasmosis, and for some other Anaplasma spp. that suggests a broader medical relevance of this genus. Genetic diversity of Anaplasma spp. has been intensively studied in recent years, and it has been shown that some Anaplasma spp. can be considered as a complex of genetically distinct lineages differing by geography, vectors, and host tropism. The aim of this review was to summarize the current knowledge concerning the natural history, pathogenic properties, and genetic diversity of Anaplasma spp. and some unclassified genovariants with particular attention to their genetic characteristics. The high genetic variability of Anaplasma spp. prompted us to conduct a detailed phylogenetic analysis for different Anaplasma species and unclassified genovariants, which were included in this review. The genotyping of unclassified genovariants has led to the identification of at least four distinct clades that might be considered in future as new candidate species.

Molecular detection and genetic diversity of Rickettsia spp. in pet dogs and their infesting ticks in Harbin, northeastern China

Background

Pet dogs are important companion animals that share the environment within households, and play an important role in local community life. In addition, pet dogs also are reservoirs of zoonotic agents, including Rickettsia spp., thus increasing the risk of rickettsial infections in humans. It’s meaningful to investigate the epidemiology of rickettsial agents in pet dogs, and make contribute to the surveillance of rickettsioses in human in China.

Results

In this study, a total of 496 pet dogs’ blood samples and 343 ticks infested in pet dogs were collected, and the presence and prevalence of Rickettsia were determined by amplifying the partial gltA and 17-kDa genes, with an overall positive rate of 8.1 % in blood samples and 14.0 % in tick samples. In addition, the rrs, gltA, groEL, and ompA genes of rickettsial were also recovered to determine the species of Rickettsia detected furtherly. Sequencing blast and phylogenetic analyses revealed the presence of three human pathogenic Rickettsia species (Rickettsia raoultii, Candidatus Rickettsia tarasevichiae and Rickettsia felis) in samples associated with pet dogs. Moreover, all the sequences of Rickettsia that we obtained presented close relationship with others available in GenBank, and Rickettsia raoultii was the most predominant Rickettsia species infected in pet dogs’ blood samples or in tick samples.

Conclusions

This study provides the molecular epidemiology data about the Rickettsia spp. infection associated with pet dogs in urban areas of Harbin city. Three rickettisae species pathogenic to humans were identified from pet dogs’ blood and the infested ticks in urban areas of Harbin city. Considering the intimate relationship between human and pets, these results indicate the potential transmission risk of human rickettisal infections from pet dogs through ectoparasites, and also highlighting that more attention should be paid to rickettsial infection in pet dogs and the infested ticks from the “One health” perspective.

Distribution and molecular characterization of rickettsiae in ticks in Harbin area of Northeastern China

Tick-borne rickettsioses are world-spreading infectious zoonoses. Ticks serve as reservoirs and vectors for Rickettsia and play a key role in transmission of rickettsioses. Most of the Chinese rickettsiosis patients are reported from Northeastern China but the distribution of tick and tick-borne Rickettsia species in Northeastern China remain poorly studied. In this study, a total of 1,286 ticks were captured from the seven counties of Harbin, an area in Northeastern China, and the tick-borne Rickettsia species were identified by PCR and sequencing of rrs, gltA, groEL, ompA and 17-kDa antigen-encoding genes. Of the 5 identified tick species, Haemaphysalis longicornis and Ixodes persulcatus were the predominant tick species in the livestock and vegetation, respectively. Rickettsia raoultii and “Candidatus Rickettsia tarasevichiae” were the two detectable Rickettsia species in the ticks with a 28.8% positive rate but no rickettsiae were found in ticks of Haemaphysalis concinna. R. raoultii detected in 37.6% of the Dermacentor nuttalli, Dermacentor silvarum and H. longicornis ticks while “Ca. R. tarasevichiae” was only present in 22.8% of the I. persulcatus ticks. In particular, the positive rate of both R. raoultii and “Ca. R. tarasevichiae” in ticks from the livestock (40.7%) was significantly higher than that from the vegetation (19.5%). The results indicate that the tick and tick-borne Rickettsia species are diverse in different regions of Harbin due to geographic difference and the ticks from livestock may play a more important role in transmission of rickettsioses to human.

Rickettsiosis is a tick-borne infectious disease of global importance. The disease has been prevailing in Northeastern China but the distribution of tick and tick-borne Rickettsia species from different areas of Northeastern China remain poorly studied. We collected a total of 1,286 ticks in the seven counties with different geographic environments of Harbin, an area of Northeastern China, and all the ticks were classified as Dermacentor nuttalli, Dermacentor silvarum, Haemaphysalis concinna, Haemaphysalis longicornis or Ixodes persulcatus. A total of 28.8% of the ticks tested positive for either Rickettsia raoultii or “Candidatus Rickettsia tarasevichiae”, in which 37.6% of the D. nuttalli, D. silvarum and H. longicornis ticks were positive for R. raoultii while 22.8% of the I. persulcatus ticks were positive for “Ca. R. tarasevichiae”. The positive rate of both R. raoultii and “Ca. R. tarasevichiae” in ticks from the livestock (40.7%) was significantly higher than that from the vegetation (19.5%). All the data indicate that ticks in the Harbin area have a high infection rate with Rickettsia species and domestic animals may have a tick-livestock rickettsial circulation that may play an important role in transmission of rickettsioses.

Extensive genetic diversity of Anaplasma bovis in ruminants in Xi'an, China

Anaplasma bovis is an organism significant to cattle and buffalo since it is one of the causative agents of bovine anaplasmosis. Previous studies have shown the worldwide distribution of A. bovis. However, most of these studies about its genetic diversity only focused on the rrs gene. In this study, DNA of A. bovis was detected in blood samples of cattle and goats in Xi'an city, China by nested-PCR. Near full-length rrs, groEL, and gltA genes were amplified successfully from the positive samples. Genetic analysis showed that specific genetic marker (an insertion and a deletion) was found in the rrs sequences in some strains, as well as clone 88 from monkeys in previous study. Phylogenetic analysis based on the rrs, groEL, and gltA genes revealed that A. bovis circulating in Xi'an exhibited great genetic diversity. Our results also indicated that variants outside China presented geographic clustering, and all A. bovis isolates based on the groEL or gltA gene also showed a host origin clustering. Also of note was that the phylogenetic analyses of the groEL and gltA genes suggested that both frequent dispersals over long distances in recent years and local adaptation over long evolutionary timescales played important roles in the distribution and evolution of A. bovis in China. Finally, a potential recombination event in the genome of Zhouzhi-cattle-10 based on inconsistent positions in the groEL and gltA trees was also observed. These results also reinforce the need for assessing the pathogenicity to humans of A. bovis variants with specific marker in the rrs gene.

Molecular characterization of tick-borne bacteria and protozoans in yaks (Bos grunniens), Tibetan sheep (Ovis aries) and Bactrian camels (Camelus bactrianus) in the Qinghai-Tibetan Plateau Area, China

Due to the specific plateau climate, a variety of unique animals live in the Qinghai-Tibetan Plateau Area (QTPA) including yaks (Bos grunniens), Tibetan sheep (Ovis aries) and Bactrian camels (Camelus bactrianus). However, information on tick-borne diseases (TBDs) in the QTPA and on the molecular characteristics of tick-borne pathogens (TBPs) in the area is limited. Therefore, the aim of this study was to investigate Anaplasma spp., Babesia spp., Theileria spp., Borrelia burgdorferi sensu lato and Rickettsia spp. infecting yaks, Tibetan sheep and camels in this area. A total of 276 animals were screened. Overall, 84.5% (164/194) of yaks, 58% (23/40) of Tibetan sheep, and 38% (16/42) of camels tested positive for at least one pathogen. Theileria spp., Anaplasma ovis and spotted fever group (SFG) Rickettsia spp. were detected as TBPs in the current study with overall infection rates of 10.9% (30/276), 8.3% (23/276) and 62.9% (171/276), respectively. Further study revealed that 1.5% (3/194) of the yaks were infected with Theileria sp. OT3, 1.5% (3/194) with T. luwenshuni, 6.2% (12/194) with T. uilenbergi, 1.1% (2/194) with T. ovis and 82% (159/194) with SFG Rickettsia spp. It was also shown that 58% (23/40) of the Tibetan sheep were infected with A. ovis and 15% (6/40) with T. ovis. Among the camels, 10% (4/42) were infected with T. equi, while 29% (12/42) were positive for Rickettsia spp. Sequence analysis revealed that the Rickettsia spp. infecting yaks and camels were Rickettsia raoultii and Rickettsia slovaca. To the best of our knowledge, this study reports the first detection and characterization of these pathogens in yaks, Tibetan sheep and camels in the country, except for T. luwenshuni infections in yaks.

Genetic characterization of Anaplasma phagocytophilum strains from goats (Capra aegagrus hircus) and water buffalo (Bubalus bubalis) by 16S rRNA gene, ankA gene and multilocus sequence typing

Anaplasma phagocytophilum is a Gram-negative obligate intracellular bacterium that replicates in neutrophil granulocytes. It is transmitted by ticks and causes tick-borne fever in domestic ruminants such as sheep, cattle and goats. However, in contrast to sheep and cattle little is known about the clinical course of infection in goats. We report here on three cases of symptomatic infection with A. phagocytophilum in two goats (Capra aegagrus hircus) and one water buffalo (Bubalus bubalis). The animals showed symptoms and laboratory findings similar to sheep and cattle. To our knowledge, this is the first report on the symptomatic infection of water buffalos with A. phagocytophilum. The infecting strains were genetically characterized by 16S rRNA gene, ankA gene and multilocus sequence typing (MLST). Four other strains from asymptomatically infected goats were also included. The ankA sequences from five goats were part of the formerly described ankA gene clusters I and IV that are known to contain A. phagocytophilum strains from sheep and cattle. However, the sequences from one goat and from the water buffalo belonged to ankA gene cluster II that was formerly described to be restricted to roe deer. A similar observation was made for MLST as three goats clustered with sequences from sheep and cattle, whereas three other goats and the water buffalo were found to be part of the roe deer cluster. However, since most of the strains from sheep and cattle were distinct from the roe deer strains, roe deer might not represent major reservoir hosts for tick-borne fever in domestic ruminants. When differing parts of the 16S rRNA gene were used for typing the results were conflicting. This shows that the use of a standardized typing method such as MLST is highly desirable to generate easily comparable results.

GroEL gene typing and genetic diversity of Anaplasma bovis in ticks in Shaanxi, China

Anaplasma bovis, causative agent of bovine anaplasmosis, is usually identified by nested-PCR amplifying the rrs gene. However, it is difficult to determine the genetic relationship among different variants within A. bovis using this gene because of high conservation. In this study, two tick species, identified as Rhipicephalus microplus and Haemaphysalis longicornis based on morphological and molecular methods by analyzing COI gene, were collected from cattle, goat or sheep. Subsequently, A. bovis was initially detected by PCR amplifying the rrs gene in ticks in Shaanxi Province, China. The sequencing and Blast results showed that some false positive samples were found when only based on the amplification of partial rrs gene, presenting these sequences resembled those of other Alphaproteobacteria rather than A. bovis. Although major surface proteins genes were proposed and used successfully to identify members within Anaplasmataceae, these genes were unavailable for A. bovis. Hence, primers targeting the groEL gene were designed and a PCR assay was developed. The PCR products were sequenced and similarity and phylogenetic analysis suggested all these sequences are the groEL gene of A. bovis. In addition, phylogenetic analysis based on the groEL gene also revealed the genetic diversity of A. bovis worldwide, as well as in Shaanxi Province of China, which wasn't reflected by analyzing the rrs gene. In sum, groEL gene is important for molecular detection and phylogenetic analysis of A. bovis.

Molecular detection of spotted fever group rickettsiae in hard ticks, northern China

Spotted fever group (SFG) rickettsiae are important causative agents of (re)emerging tick-borne infectious diseases in humans, and ticks play a key role in their maintenance and transmission. In this study, hard ticks were collected from five sampling sites in North China in 2017 and 2018. Of them, Haemaphysalis longicornis, Rhipicephalus microplus and Dermacentor nuttalli were collected from livestock (sheep and goats) and the vegetation, Hyalomma asiaticum from sheep, goats and camels, and Hyalomma marginatum from sheep and goats. The SFG rickettsiae were identified in these ticks by amplifying the partial rrs and complete 17-kDa genes, with an overall infection rate of 52.9%. In addition, the nearly full-length rrs and gltA and partial ompA genes were recovered to classify the species of SFG rickettsiae further. Phylogenetic analysis revealed the presence of three human pathogenic species in Hy. asiaticum, Hy. marginatum, Ha. longicornis and De. nuttalli, including two cultured ones (Rickettsia raoultii and Rickettsia aeschlimannii) and one uncultured (Candidatus R. jingxinensis). Furthermore, partial groEL gene was also obtained, and phylogenetic trees were also reconstructed to better understand the genetic relationship with known sequences in each SFG rickettsiae species detected in the current study. Notably, the R. aeschlimannii sequences described in this study were closely related to those from abroad rather than from another part of China, indicating their different origin. However, the R. raoultii and Ca. R. jingxinensis sequences presented close relationship with variants from other parts of China. In sum, our data revealed SFG rickettsiae species in northern China, highlighting the need for surveillance of their infection in local humans.

Molecular epidemiology, associated risk factors, and phylogenetic analysis of anaplasmosis in camel

Camel Anaplasmosis is caused by members of family Anaplasmatacae, a tick transmitted, obligate intracellular bacteria. The etiological bacteria are transmitted by ixodid tick species. The species have multi host range distribution that is why it is crucial to diagnose it timely. The aim of present study was to investigate the molecular epidemiology i.e. prevalence and risk factors analysis of camel anaplasmosis. Furthermore, variations in hematological standards were also evaluated. The study found an overall 13.33% prevalence in camels. The confirmation of PCR positive samples for Anaplasma spp. was made through sequencing, the study isolatesshowed high homology with Iranian, Chinese, Philippines and South African isolates of Anaplasmatacae (Accession numbers'; KX765882, KP062964, KY242456, LC007100 and U54806) on BLAST queries. The phylogenetic analysis revealedthree study isolates of present study clustered with each other and the cluster was found closer to Chinese isolate of A. phagocytophilum (KY242456), A. marginale (KU586048), and Mongolian isolates of A. ovis (LC194134). Two of the isolates resembled Iranian isolate of Candidatus Anaplasmacamelii (KX765882), while one isolate resembled with Chinese isolates of A. Platys (KX987336) and Croatian isolates of A. Platys (KY114935). The key risk factors odds ratio (OR>1) identified for occurrence of camel anaplasmosis using regression model found sex and age of animal, previous tick history, tick infestation and tick control status, housing type, cracks in walls, rearing system and other species in surrounding as the key risk factors. The hematological parameters like lymphocytes, monocytes, granulocytes and platelets count were significantly decreased (p < 0.05) in diseased camels than healthy. This is the first ever molecular data on camel anaplasmosis in Pakistan. The disease should be monitored unceasingly as the etiologies have multi host distribution. Prompt attention should be offered to animals because neutropenia, lymphopenia and thrombocytopenia can exacerbate the disease by making the animal predisposed to otherdiseases.

Identification of tick-borne pathogen diversity by metagenomic analysis in Haemaphysalis longicornis from Xinyang, China

Background

A wide variety of pathogens could be maintained and transmitted by Haemaphysalis longicornis. The aim of this study is to systematically examine the variety of pathogens carried by Haemaphysalis longicornis, an importnatn vector, in tick-borne diseases epidemic area, and to estimate the risk of human infection imposed by tick bites.

Methods

Adult questing ticks were collected in Xinyang, central China. Genomic DNA and RNA were extracted from 144 H. longicornis ticks individually, and sequenced respectively as the templates for high-throughput sequencing. Clean reads were compared against the database of NCBI nucleotide collection and specific PCR was performed to confirm the presence of pathogen. Phylogenetic analysis was performed to explore the evolutionary status of pathogens.

Results

The assignment of reads to taxa based on BLASTN results revealed the existence of several potential pathogens, including Anaplasma spp., Rickettsia spp., Babesia sp., as well as severe fever with thrombocytopenia syndrome bunyavirus (SFTSV). Comfirmantory PCR assays revealed the existence of Anaplasma bovis (13/144, 9.03%), Anaplasma centrale (2/144, 1.39%), Rickettsia heilongjiangensis (3/144, 2.08%), Rickettsia sp. LON-13 (1/144, 0.69%), Rickettsia raoultii (5/144, 3.47%), Babesia sp. (1/144, 0.69%). SFTSV accounted for the highest detected pathogen with a positive rate of 18.75% (27/144). Three of the ticks (2.08%) were co-infected with SFTSV and A. bovis.

Conclusion

Our study provided a broadened list of microorganism that harbored by H. longicornis. In previously unrecognized endemic regions, prokaryotic and eukaryotic infection including Anaplasma spp., Rickettsiae spp., and Babesia spp. should be considered, along with the well-known SFTSV for patients with tick bites history. A novel Babesia species was identified in local natural foci, which needs further investigation in the future.

Electronic supplementary material

The online version of this article (10.1186/s40249-018-0417-4) contains supplementary material, which is available to authorized users.

Molecular detection of Anaplasma phagocytophilum-like Anaplasma spp. and pathogenic A. Phagocytophilum in cattle from South Korea

Anaplasma phagocytophilum is the causative agent of human granulocytic anaplasmosis and tick-borne fever in domestic ruminants. Differential diagnosis of zoonotic and pathogenic tick-borne diseases like granulocytic anaplasmosis is important for the efficient implementation of control programs. Thus, the differentiation of pathogenic A. phagocytophilum from non-pathogenic A. phagocytophilum-like (APL) Anaplasma spp. is essential. Recent molecular analyses of APL revealed its distinct phylogenetic position from A. phagocytophilum. This study was conducted to detect A. phagocytophilum and genetically related strains in 764 cattle in South Korea using PCR and restriction fragment length polymorphism assays. APL clade A and A. phagocytophilum were identified in 20 (2.6%) and 16 (2.1%) cattle, respectively, with 16 cattle (2.1%) displaying co-infection. The 16S rRNA sequences of APL clade A were similar (98.3-99.9%) to those clustered in the APL clade A from eastern Asia. The A. phagocytophilum 16S rRNA sequence shared 98.6-100% identity to those of the A. phagocytophilum group. We used PCR to amplify the groEL and msp2 genes from the 20 samples positive for the 16S rRNA gene and found that 16 were positive for the groEL sequences in the APL clade A, which showed identity (82.8-84.4%) to those clustered in the APL clade A from Japan. Amplification of msp2 was unsuccessful. The co-infection results suggested sequence diversity in Anaplasma spp. Till date, both A. phagocytophilum and APL have been reported to be distributed separately in several animals throughout South Korea. This report is the first co-detection of A. phagocytophilum and APL in Korean cattle using molecular methods. Further studies are needed to provide additional molecular background and trace the evolutionary tree of Anaplasma species in animals and ticks.

First report of Ehrlichia infection in goats, China

Ehrlichiosis is an emerging infectious disease of domestic animals which is transmitted by ticks. This disease has been reported earlier in most parts of China in dogs, cattle and humans, but there is no published data regarding this disease in goats. The present study provided the evidence of Ehrlichia infection in goats in Wuhan, China on the basis of clinical signs, gross lesions, serum-biochemical, histopathological and PCR. Twenty four goats were presented to the veterinary hospital of Huazhong Agricultural University during July, 2016. The goats were diagnosed for Ehrlichia in monocytic and granulocytic forms by blood smear examination. Further confirmation was done by PCR examination, while histopathological examination revealed degeneration and inflammation in different tissues. The biochemical criterion and blood samples analysis showed significant (P < 0.05) changes. The present study reported that goats are naturally exposed to Ehrlichia infection. To the best of our knowledge, this is the first clinical report of Ehrlichia infection in goats infested with infected ticks.

A rapid, simple and sensitive loop-mediated isothermal amplification method to detect Anaplasma bovis in sheep and goats samples

A loop-mediated isothermal amplification (LAMP) technique has been widely used in detecting the nucleic acid of various pathogenic bacteria. In this study, a set of four LAMP primers was designed to specifically test Anaplasma bovis. The LAMP assay was performed at 62°C for 60min in a water bath. The specificity was confirmed by amplifying A. bovis isolate, while no cross reaction was observed with other five pathogens (Anaplasma bovis, Anaplasma phagocytophilum, Theileria luwenshuni, Babesia motasi and Schistosoma japonicum). The sensitivity of LAMP was 5×10⁰copies/μL, 100 times more than that of conventional PCR (5×10²copies/μL). Of 120 blood DNA extracted from sheep and goats field samples, 81 (67.5%), 22 (18.3%) and 43 (35.8%) were positively detected by LAMP, conventional PCR and nested PCR, respectively. The findings indicated that the developed LAMP assay is a new convenient tool for rapid and cost-effective detection of A. bovis.

Molecular Detection and Characterization of Zoonotic and Veterinary Pathogens in Ticks from Northeastern China

Tick-borne diseases are considered as emerging infectious diseases in humans and animals in China. In this study, Ixodes persulcatus (n = 1699), Haemaphysalis concinna (n = 412), Haemaphysalis longicornis (n = 390), Dermacentor nuttalli (n = 253), and Dermacentor silvarum (n = 204) ticks were collected by flagging from northeastern China, and detected for infection with Anaplasma, Ehrlichia, Babesia, and Hepatozoon spp. by using nested polymerase chain reaction assays and sequencing analysis. Anaplasma phagocytophilum was detected in all tick species, i.e., I. persulcatus (9.4%), H. longicornis (1.9%), H. concinna (6.5%), D. nuttalli (1.7%), and D. silvarum (2.3%); Anaplasma bovis was detected in H. longicornis (0.3%) and H. concinna (0.2%); Ehrlichia muris was detected in I. persulcatus (2.5%) and H. concinna (0.2%); Candidatus Neoehrlichia mikurensis was only detected in I. persulcatus (0.4%). The Ehrlichia variant (GenBank access number KU921424), closely related to Ehrlichia ewingii, was found in H. longicornis (0.8%) and H. concinna (0.2%). I. persulcatus was infected with Babesia venatorum (1.2%), Babesia microti (0.6%), and Babesia divergens (0.6%). Additionally, four Babesia sequence variants (GenBank access numbers 862303–862306) were detected in I. persulcatus, H. longicornis, and H. concinna, which belonged to the clusters formed by the parasites of dogs, sheep, and cattle (B. gibsoni, B. motasi, and B. crassa). Two Hepatozoon spp. (GenBank access numbers KX016028 and KX016029) associated with hepatozoonosis in Japanese martens were found in the collected ticks (0.1–3.1%). These findings showed the genetic variability of Anaplasma, Ehrlichia, Babesia, and Hepatozoon spp. circulating in ticks in northeastern China, highlighting the necessity for further research of these tick-associated pathogens and their role in human and animal diseases.

Molecular detection of tick-borne bacteria and protozoa in cervids and wild boars from Portugal

Background

Wildlife can act as reservoir of different tick-borne pathogens, such as bacteria, parasites and viruses. The aim of the present study was to assess the presence of tick-borne bacteria and protozoa with veterinary and zoonotic importance in cervids and wild boars from the Centre and South of Portugal.

Methods

One hundred and forty one blood samples from free-ranging ungulates including 73 red deer (Cervus elaphus), 65 wild boars (Sus scrofa) and three fallow deer (Dama dama) were tested for the presence of Anaplasma marginale/A. ovis, A. phagocytophilum, Anaplasma/Ehrlichia spp., Babesia/Theileria spp., Borrelia burgdorferi (sensu lato) (s.l.), and Rickettsia spp. DNA by PCR.

Results

Anaplasma spp. DNA was detected in 33 (43.4 %) cervids (31 red deer and two fallow deer) and in two (3.1 %) wild boars while Theileria spp. were found in 34 (44.7 %) cervids (32 red deer and two fallow deer) and in three (4.6 %) wild boar blood samples. Sequence analysis of msp4 sequences identified A. marginale, A. ovis, while the analysis of rDNA sequence data disclosed the presence of A. platys and A. phagocytophilum and T. capreoli and Theileria sp. OT3. Anaplasma spp./Theileria spp. mixed infections were found in 17 cervids (22.4 %) and in two wild boars (3.1 %). All samples were negative for Babesia sp., B. burgdorferi (s.l.), Ehrlichia sp. or Rickettsia sp.

Conclusions

This is the first detection of Anaplasma marginale, A. ovis, A. phagocytophilum, A. platys, Theileria capreoli and Theileria sp. OT3 in cervids and wild boars from Portugal. Further studies concerning the potential pathogenicity of the different species of  Anaplasma and Theileria infecting wild ungulates, the identification of their vector range, and their putative infectivity to domestic livestock and humans should be undertaken.