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Ticks are a major parasite on the Qīnghăi-Tibet Plateau, western China, and represent an economic burden to agriculture and animal husbandry. Despite research on tick-borne pathogens that threaten humans and animals, the viromes of dominant tick species in this area remain unknown. In this study, we collected Dermacentor nuttalli ticks near Qīnghăi Lake and identified 13 viruses belonging to at least six families through metagenomic sequencing. Four viruses were of high abundance in pools, including Xīnjiāng tick-associated virus 1 (XJTAV1), and three novel viruses: Qīnghăi Lake virus 1, Qīnghăi Lake virus 2 (QHLV1, and QHLV2, unclassified), and Qīnghăi Lake virus 3 (QHLV3, genus Uukuvirus of family Phenuiviridae in order Bunyavirales), which lacks the M segment. The minimum infection rates of the four viruses in the tick groups were 8.2%, 49.5%, 6.2%, and 24.7%, respectively, suggesting the prevalence of these viruses in D. nuttalli ticks. A putative M segment of QHLV3 was identified from the next-generation sequencing data and further characterized for its signal peptide cleavage site, N-glycosylation, and transmembrane region. Furthermore, we probed the L, M, and S segments of other viruses from sequencing data of other tick pools by using the putative M segment sequence of QHLV3. By revealing the viromes of D. nuttalli ticks, this study enhances our understanding of tick-borne viral communities in highland regions. The putative M segment identified in a novel uukuvirus suggests that previously identified uukuviruses without M segments should have had the same genome organization as typical bunyaviruses. These findings will facilitate virus discovery and our understanding of the phylogeny of tick-borne uukuviruses. [ABSTRACT FROM AUTHOR]

Over the past decades, red meat allergy, also known as mammalian meat allergy, which manifests differently from classic food allergies, has been reported in different countries and regions, including China. The allergen of this disease is not a protein but an oligosaccharide: galactose‐α‐1,3‐galactose, i.e., alpha‐gal or α‐gal. Therefore, this clinical syndrome is also called α‐gal syndrome (AGS). It clinically manifests as delayed anaphylaxis, i.e., patients generally develop allergic symptoms 2–6 h after ingesting red meat. This clinical manifestation is believed to be related to sensitization to α‐gal after tick bites. Sensitized individuals may also develop anaphylaxis after ingesting food and medicine or being exposed to medical equipment containing α‐gal, such as cetuximab and gelatin. Here, the literature on AGS is reviewed for a better understanding of its pathogenesis, clinical diagnosis, and treatment. [ABSTRACT FROM AUTHOR]

Serine proteinase inhibitors (serpins), identified from the hard tick Haemaphysalis longicornis of China, play significant roles in various animal physiological processes. In this study, we showed that H. longicornis serpins (Hlserpin‐a and Hlserpin‐b) were induced during blood‐feeding in nymph ticks and exhibited anticoagulation activity in vitro. Silencing Hlserpins through RNA interference (RNAi) significantly impaired tick feeding. Immunization of mice with recombinant Hlserpins or passive transfer of Hlserpin antiserum significantly curtails the efficacy of tick feeding. Concurrently, the transmission of the Langat virus (LGTV) from ticks to mice witnessed a substantial decrease when Hlserpins were silenced. Our findings suggest that inhibiting Hlserpins can hamper tick engorgement and pathogen transmission, indicating the potential of Hlserpins as a vaccine to counter tick‐borne diseases. [ABSTRACT FROM AUTHOR]

Anaplasma and Ehrlichia are tick-borne bacterial pathogens that cause anaplasmoses and ehrlichioses in humans and animals. In this study, we examined the prevalence of Anaplasma and Ehrlichia species in ticks and domesticated animals in Suizhou County, Hubei Province in the central China. We used PCR amplification and DNA sequencing of the 16S rRNA, groEL, and gltA genes to analyze. We collected 1900 ticks, including 1981 Haemaphysalis longicornis and 9 Rhipicephalus microplus, 159 blood samples of goats (n = 152), cattle (n = 4), and dogs (n = 3) from May to August of 2023. PCR products demonstrated that Anaplasma bovis, Anaplasma capra, and an Ehrlichia species were detected in the H. longicornis with the minimum infection rates (MIR) of 1.11%, 1.32%, and 0.05%, respectively; A. bovis, A. capra, and unnamed Anaplasma sp. were detected in goats with an infection rate of 26.31%, 1.31% and 1.97%, respectively. Anaplasma and Ehrlichia species were not detected from cattle, dogs and R. microplus ticks. The genetic differences in the groEL gene sequences of the Anaplasma in the current study were large, whereas the 16S rRNA and gltA gene sequences were less disparate. This study shows that ticks and goats in Suizhou County, Hubei Province carry multiple Anaplasma species and an Ehrlichia species, with relatively higher infection rate of A. bovis in goats. Our study indicates that multiple Anaplasma and Ehrlichia species exist in ticks and goats in the central China with potential to cause human infection. [ABSTRACT FROM AUTHOR]

Japanese spotted fever (JSF) is caused by Rickettsia japonica, mainly vectored by hard ticks. However, whether R. japonica can be transmitted by other arthropods remains unknown.Moreover, it is of interest to investigatewhether other Rickettsia species cause spotted fever in endemic areas. In this study, a survey of Rickettsia species was performed in hematophagous arthropods (mosquitoes, tabanids, and ticks) from endemic areas for JSF in Hubei Province, central China. The results showed that the diversity and prevalence of Rickettsia species in mosquitoes are low, suggesting that mosquitoes may not be the vector of zoonotic Rickettsia species. A novel Rickettsia species showed a high prevalence (16.31%, 23/141) in tabanids and was named "Candidatus Rickettsia tabanidii." It is closely related to Rickettsia from fleas and mosquitoes; however, its pathogenicity in humans needs further investigation. Five Rickettsia species were identified in ticks. Rickettsia japonica, the agent of JSF, was detected only in Haemaphysalis longicornis and Haemaphysalis hystricis, suggesting that they may be the major vectors of R. japonica. Notably, two novel species were identified in H. hystricis ticks, one belonging to the spotted fever group and the other potentially belonging to the ancestral group. The latter one named "Candidatus Rickettsia hubeiensis" may provide valuable insight into the evolutionary history of Rickettsia. [ABSTRACT FROM AUTHOR]

Background: Hyalomma ticks are widely distributed in semi-arid zones in Northwest China. They have been reported to harbor a large number of zoonotic pathogens. Methods: In this study, a total of 334 Hyalomma asiaticum ticks infesting domestic animals were collected from four locations in Xinjiang, Northwest China, and the bacterial agents in them were investigated. Results: A putative novel Borrelia species was identified in ticks from all four locations, with an overall positive rate of 6.59%. Rickettsia sibirica subsp. mongolitimonae, a human pathogen frequently reported in Europe, was detected for the second time in China. Two Ehrlichia species (Ehrlichia minasensis and Ehrlichia sp.) were identified. Furthermore, two Anaplasma species were characterized in this study: Candidatus Anaplasma camelii and Anaplasma sp. closely related to Candidatus Anaplasma boleense. It is the first report of Candidatus Anaplasma camelii in China. Conclusions: Six bacterial agents were reported in this study, many of which are possible or validated pathogens for humans and animals. The presence of these bacterial agents may suggest a potential risk for One Health in this area. [ABSTRACT FROM AUTHOR]

Emerging pathogenic tick‐borne viruses (TBVs) have attracted a great deal of attention due to their significant impact on human and animal health. A novel orthonairovirus named Dadong virus (DDV) was isolated from Haemaphysalis concinna ticks in the Changbai Mountain region on the China–North Korea border. DDV can induce cytopathic effects in mammalian and human cell lines. Phylogenetic analysis showed that it belongs to the genus Orthonairovirus, family Nairoviridae, exhibiting 72.4%–81.3% nucleic acid identity to Tofla orthonairovirus, known to cause lethal infection in IFNAR KO mice. The first serological evidence of DDV circulating in cattle and mice was also obtained, with 4.0% (1/25) of cattle and 2.27% (1/44) of mice seropositive for DDV. Further investigations, including serological surveys using human samples, are required to assess the public health risk posed by DDV. [ABSTRACT FROM AUTHOR]

Purpose: Ticks are dangerous ectoparasites for humans and other animals, and tick-borne pathogens of Bactrian camels have been epidemiologically surveyed in Gansu Province, China. We aimed to determine the current distribution of tick-borne pathogens among Bactrian camels in Gansu during August 2013 using molecular tools. Methods: All ticks underwent morphological identification. We extracted DNA from the blood samples and ticks, screened them for Theileria, Babesia, Anaplasma, and Ehrlichia using standard or nested PCR with specific primers. Results: All ticks collected from the skin were identified as Hyalomma asiaticum. The blood and tick samples harbored similar pathogens, including the Theileria species, T. annulata, T. luwenshuni, T. uilenbergi, and T. capreoli, the Anaplasma species A. bovis and uncultured Anaplasma, the Ehrlichia species E. canis and uncultured Ehrlichia, and a new haplotype of Babesia species. Conclusion: Our findings of anaplasmataceae and piroplasmida in Bactrian camels in Gansu provide a theoretical basis for deeper investigation into the epidemiology of tick-borne pathogens in these camels. [ABSTRACT FROM AUTHOR]

Background: Rodents play an important role in the life cycle of ixodid and argasid ticks, particularly as hosts of larvae and nymphs. The great gerbil (Rhombomys opimus), the preferred prey item of several carnivores (e.g. the red fox and marbled polecat), is the dominant rodent species in the Gurbantunggut Desert in northwestern China. The aim of this study was to investigate tick species associated with different hosts in the habitat of great gerbils, including wildlife and livestock. Methods: During 2018–2023, ticks were removed from 326 great gerbils, two red foxes (Vulpes vulpes), three marbled polecats (Vormela peregusna), 35 pastured sheep (Ovis aries), and one long-eared desert hedgehog (Hemiechinus auritus) in the Gurbantunggut Desert. Ticks were identified according to standard morphological keys. Then, they were further analyzed by molecular and phylogenic methods based on two mitochondrial markers, 16S rDNA and cytochrome c oxidase subunit I (COI) genes. Results: A total of 889 ticks were collected, representing five species. These included Hyalomma asiaticum (n = 425: 24 larvae, 79 nymphs and 322 adults), Rhipicephalus turanicus (n = 153: 2 nymphs and 151 adults), Haemaphysalis erinacei (n = 298: 4 larvae, 7 nymphs and 287 adults), Ixodes acuminatus (n = 7: 4 nymphs and 3 adults) and Ornithodoros tartakovskyi (6 adults). Based on COI sequences, molecular and phylogenetic analyses showed that (i) I. acuminatus from great gerbils and marbled polecats clustered with I. acuminatus reported from Europe; (ii) O. tartakovskyi found in northwestern China belonged to an independent clade; (iii) Hy. asiaticum, R. turanicus and Ha. erinacei had 100% sequence identities to conspecific ticks sampled previously in China. Conclusions: The great gerbil is an important host for the developmental stages of I. acuminatus, O. tartakovskyi, Ha. erinacei, Hy. asiaticum and R. turanicus, thus supporting the life cycle of several tick species which, as adults, parasitize predators (red fox and marble polecat) as well as pastured sheep and hedgehogs in the Gurbantunggut Desert. Ixodes acuminatus and O. tartakovskyi were found for the first time on great gerbil and marbled polecat, respectively. [ABSTRACT FROM AUTHOR]

Haemaphysalis longicornis (the longhorned tick), the predominant tick species in China, serves as a vector for a variety of pathogens, and is capable of transmitting the tick-borne encephalitis virus (TBEV), the causative agent of tick-borne encephalitis. However, it is unclear how these ticks transmit TBEV. Langat virus (LGTV), which has a reduced pathogenicity in humans, has been used as a surrogate for TBEV. In this study, we aimed to investigate the vector competence of H. longicornis to transmit LGTV and demonstrate the efficient acquisition and transmission of LGTV between this tick species and mice. LGTV localization was detected in several tick tissues, such as the midgut, salivary glands, and synganglion, using quantitative PCR and immunohistochemical staining with a polyclonal antibody targeting the LGTV envelope protein. We demonstrated the horizontal transmission of LGTV to different developmental stages within the same generation but did not see evidence of vertical transmission. It was interesting to note that we observed mice acting as a bridge, facilitating the transmission of LGTV to neighboring naïve ticks during blood feeding. In conclusion, the virus–vector–host model employed in this study provides valuable insights into the replication and transmission of LGTV throughout its life cycle. [ABSTRACT FROM AUTHOR]

Ticks are important vectors of zoonotic diseases and play a major role in the circulation and transmission of many rickettsial species. The aim of this study was to investigate the carriage of Candidatus Rickettsia tarasevichiae (CRT) in a total of 1168 ticks collected in Inner Mongolia to elucidate the potential public health risk of this pathogen, provide a basis for infectious disease prevention, control and prediction and contribute diagnostic ideas for clinical diseases that present with fever in populations exposed to ticks. A total of four tick species, Haemaphysalis concinna (n = 21), Dermacentor nuttalli (n = 122), Hyalomma marginatum (n = 148), and Ixodes persulcatus (n = 877), were collected at nine sampling sites in Inner Mongolia, China, and identified by morphological and molecular biological methods. Reverse transcription PCR targeting the 16S ribosomal RNA (rrs), gltA, groEL, ompB and Sca4 genes was used to detect CRT DNA. Sequencing was used for pathogen species confirmation. The molecular epidemiological analysis showed that three species of ticks were infected with CRT, and the overall positive rate was as high as 42%. The positive rate of I. persulcatus collected in Hinggan League city was up to 96%, and that of I. persulcatus collected in Hulun Buir city was 50%. The pool positive rates of D. nuttalli and H. marginatum collected in Bayan Nur city and H. concinna collected in Hulun Buir city were 0%, 28% and 40%, respectively. This study revealed the high prevalence of CRT infection in ticks from Inner Mongolia and the first confirmation of CRT detected in H. marginatum in China. The wide host range and high infection rate in Inner Mongolia may dramatically increase the exposure of CRT to humans and other vertebrates. The role of H. marginatum in the transmission of rickettsiosis and its potential risk to public health should be further considered. [ABSTRACT FROM AUTHOR]

As one of the most important disease vectors worldwide, ticks can transmit a number of pathogenic organisms to humans and domestic animals and cause a variety of important natural focal diseases and zoonoses. Domestic livestock play a vital role in the dispersal of ticks from the field environment to the human settlement, contributing to the prevalence of tick-borne diseases. Identification of the tick control region could contribute a vital role in strategic planning and cost-effective tick control measures. However, little is known about the spatial distribution characteristics of ticks around livestock sheds, which will lead to abusage and overuse of insecticides. Therefore, this study aimed to explore spatial distribution characteristics and correlation factors of ticks around goat sheds. A total of 3898 ticks were collected from eight goat sheds from April to June in Jinan city. All the sampled ticks belonged to the same species, namely Haemaphysalis longicornis, and 88.8% of them were nymphs. A significant positive correlation was noted between free-living ticks and parasitic ticks (r = 0.411, P < 0.001). However, there was a significant negative correlation between number of free-living ticks and distance from the goat sheds (r = -0.622, P < 0.001). Within 20 m from the goat sheds, 2211 ticks were collected respectively, representing 56.7% of the total free-living ticks. At a distance of 30 m, 57.6% decline in the tick density was found with a significant difference (q = 5.534, P < 0.001). In conclusion, focusing control efforts near the goat sheds should be recommend for tick prevention and control. [ABSTRACT FROM AUTHOR]

Important tick-borne diseases include spotted fever group Rickettsia (SFGR), Anaplasma, and Ehrlichia, which cause harm to animal and human health. Ixodidae are the primary vectors of these pathogens. We aimed to analyze the prevalence and genetic diversity of SFGR, Anaplasma, and Ehrlichia species in the Ixodidae in Shaanxi Province, China. Herein, 1,113 adult Ixodidae ticks were collected from domestic cattle and goats, and detected using nested PCR. A total of four Ixodidae species were collected and Ca. R. jingxinensis (20.58%, 229/1113), A. bovis (3.05%, 34/1113), A. capra (3.32%, 37/1113), A. marginale (0.18%, 2/1113), E. sp. Yonaguni138 (0.18%, 2/1113), and a potent novel Ehrlichia species named E. sp. Baoji96 (0.09%, 1/1113) were detected. A. marginale was detected for the first time in Rhipicephalus microplus. E. sp. Baoji96 was closely related to E. chaffeensis and was first identified in Haemaphysalis longicornis. In addition, co-infection with two Rickettsiales pathogens within an individual tick was detected in 10 (1.54%) ticks. This study provides a reference for the formulation of biological control strategies for ticks and tick-borne diseases in Shaanxi Province, and could lead to an improved control effect. [ABSTRACT FROM AUTHOR]

Ticks are obligate ectoparasites and vectors of a variety of pathogens in humans and animals. Certain tick-borne pathogens (TBPs) have been identified as the cause of zoonoses, posing potentially significant threats to the human health and livestock industries. Fungi are one of the major TBPs that can affect ticks and cause disease in humans. At present, there are few studies on the diversity of fungal microbial communities carried by Ixodes. Therefore, profiling tick-borne fungi will contribute to understanding the tick-fungal interaction. This study evaluated the community profile and differences in the fungal microbiome in Ixodidae collected on parasitic ticks or nonparasitic ticks in Wuwei, Gansu Province, China. The Shannon index, Simpson index, and Richness index were used to evaluate the diversity of mycobiome. Principle coordinates analysis (PCoA) was conducted to determine patterns of diversity in mycobiome. Using correlation analysis to determine the correlation of mycobiome. The results show that the high-throughput sequencing of the internal transcribed spacer gene generated 3,634,943 raw reads and 7,482 amplicon sequence variants. The dominant tick species in this region was Dermacentor nuttalli (Ixodidae). The mycobiome belonged to four classes—Dothideomycetes, Sordariomycetes, Ustilaginomycetes, and Tremellomycetes—and more than 261 genera, the most abundant genera were Cladosporium, Purpureocillium, Aureobasidium, Tranzscheliella, and Sporormiella. Alpha diversity indicated that the abundance and evenness of mycobiome were marginally higher in nonparasitic ticks than in parasitic ticks. PCoA showed that the community structures of parasitic ticks vary from nonparasitic ticks, samples from nonparasitic ticks tended to cluster more closely than those from the parasitic ticks. Correlation analysis indicated that there was a significant positive correlation or negative correlation between the mycobiome. Our results indicate that the mycobiome carried by Dermacentor nuttalli had rich diversity, and there was a significant difference in mycobiome between parasitic ticks and nonparasitic ticks. These findings may conducive to understand the complex interaction between ticks and commensal fungi and provide help for the further exploration of the behavioral characteristics of ticks and formulation of effective biological control measures. [ABSTRACT FROM AUTHOR]

The uncertainty and unknowability of emerging infectious diseases have caused many major public health and security incidents in recent years. As a new tick‐borne disease, Dabieshan tick virus (DBTV) necessitate systematic epidemiological and spatial distribution analysis. In this study, tick samples from Liaoning Province were collected and used to evaluate distribution of DBTV in ticks. Outbreak points of DBTV and the records of the vector Haemaphysalis longicornis in China were collected and used to establish a prediction model using niche model combined with environmental factors. We found that H. longicornis and DBTV were widely distributed in Liaoning Province. The risk analysis results showed that the DBTV in the eastern provinces of China has a high risk, and the risk is greatly influenced by elevation, land cover, and meteorological factors. The risk geographical area predicted by the model is significantly larger than the detected positive areas, indicating that the etiological survey is seriously insufficient. This study provided molecular and important epidemiological evidence for etiological ecology of DBTV. The predicted high‐risk areas indicated the insufficient monitoring and risk evaluation and the necessity of future monitoring and control work. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Dabieshan tick virus (DBTV) is a newly identified arbovirus, first detected in Haemaphysalis longicornis collected from Hubei Province in 2015. It has been confirmed that DBTV is widely distributed in Shandong Province, China. However, its entomological and epidemiological features remain to be further explored, particularly the feasibility of transovarial transmission. Our research tries to explain the possibility of transovarial transmission of DBTV from engorged female ticks to their offspring. All engorged female adult ticks were sampled from domestic sheep and allowed to lay eggs and hatch in appropriate laboratory conditions. All engorged ticks, larvae and unhatched eggs were classified into pools for nucleic acid extraction and DBTV RNA detection. According to the results of qRT-PCR, the positive rate of DBTV was 6.25% (8/128) in engorged female ticks, 3.57% (1/28) in eggs and 5% (3/60) in larvae pools, respectively. Phylogenetic analysis indicated that DBTV isolates from larvae were similar to those from maternal ticks with more than 99.5% homology, and DBTV was relatively conservative in evolution. Our findings are the first to provide molecular evidence of potential transovarial transmission of DBTV among H. longicornis. Nonetheless, the transovarial transmission of DBTV in frequency and proportion occurring in nature deserves further investigation. [ABSTRACT FROM AUTHOR]

In this study, a total of 179 ticks infesting ruminant livestock, including 166 Haemaphysalis longicornis ticks and 13 Rhipicephalus microplus ticks were collected from Yingshan county of Hubei province, China in 2021–2022. PCR testing and sequence analysis revealed that the ticks infected with various species of pathogens including Rickettsia (R. japonica), Anaplasma (A. bovis, A. ovis, A. platys, and Ca. A. boleense), Ehrlichia (E. minasensis and Ehrlichia sp.), Theileria (T. orientalis and T. luwenshuni), and Babesia (B. bigemina). The infection rates of these pathogens were 0.56, 16.76, 7.26, 2.79 and 0.56%. respectively, while only 3 of 13 R. microplus ticks were detected to be infected wth Ehrlichia sp., A. bove., or T. luwenshuni. Our results revealed that a variety of tick-borne pathogens highly carried by these ticks, specially Ha. longicornis. Therefore, it is necessary to make effective control of the ticks and the tick-borne diseases in the County. [ABSTRACT FROM AUTHOR]

Mudanjiang phlebovirus (MJPV) is a newly discovered phlebovirus, initially detected from Ixodes persulcatus ticks in China in 2022. In this study, by next-generation sequencing (NGS) on a wide variety of ticks and wild small animals in China, we detected MJPV from I. persulcatus and Meriones meridianus. Additionally, we conducted RT-PCR and sequencing on 1815 adult ticks and 805 wild small mammals collected from eight provinces in China between 2017 and 2021. MJPV RNA-positive results were found in 0.22% (4/1815) of tick samples, as well as in 0.12% (1/805) of rodent samples. All positive detections were obtained from Heilongjiang and Inner Mongolia. Sequencing analysis revealed nucleotide similarities ranging from 98.23% to 99.11%, as well as amino acid similarities ranging from 99.12% to100%, between the current MJPV strain and previously reported strains of MJPV. Phylogenetic tree analysis demonstrated that the previously reported MJPV strain along with our two variants clustered together with other tick-borne phenuiviruses, indicating their close relationship within this viral group. This study represents the first detection of MJPV infection in wild rodents, expanding the known host range for this virus in the endemic regions. [ABSTRACT FROM AUTHOR]

This article discusses the potential role of the brown dog tick, Rhipicephalus sanguineus, in the transmission of severe fever with thrombocytopenia syndrome virus (SFTSV) in Hainan Island, China. The study found that SFTSV RNA levels increased in female ticks after injection with the virus, and the virus was detected in the eggs and larvae that originated from the infected female ticks. These findings suggest that R. sanguineus may serve as a vector for SFTSV and transmit the virus through transovarial transmission. Further research is needed to fully understand the vector role of R. sanguineus in SFTSV transmission. [Extracted from the article]

Background: The order Rickettsiales contains a group of vector-borne gram-negative obligate intracellular bacteria, which often cause human emerging infectious diseases and economic losses for dairy and meat industries. The purpose of this study is to investigate the distribution of the pathogens including Rickettsia spp., Anaplasma spp., and Ehrlichia spp. in the order Rickettsiales in ticks from Yueyang, a prefecture-level city of Hunan Province in Sothern China, and assess the potentiality of transovarial transmission of these rickettsial organisms. Methods: Ticks were collected from cattle in a farm in Yueyang City and the tick DNA was used as template to amplify the htrA, rrs, gltA, ompA and ompB genes of Rickettsia as well as rrs and groEL genes of Anaplasma and Ehrlichia. Results: All ticks (465) collected were the cattle tick, Rhipicephalus microplus. PCR showed the minimum infection rate (MIR) was 1.5% (7/465) for Candidatus Rickettsia xinyangensis, 1.9% (9/465) for C. Anaplasma boleense, 1.3% (6/465) for Anaplasma platys, 0.6% (3/465) for A. marginale, and 1.17% (2/465) for each of A. bovis, Ehrlichia minasensis, and a non-classified Ehrlichia sp. A human pathogen, C. Rickettsia xinyangensis and A. platys were detected in 100% (3/3) and 33.3% (2/6) laboratory-hatched larval pools from infected females respectively. Conclusion: Our study revealed a diversity of pathogenic rickettsial species in R. microplus ticks from Hunan Province suggesting a threat to people and animals in China. This study also provided the first molecular evidence for the potential transovarial transmission of C. Rickettsia xinyangensis and A. platys in R. microplus, indicating that R. microplus may act as the host of these two pathogens. Author summary: Spotted fever group rickettsiae, Anapalsma, and Ehrlichia are tick-borne bacteria, which can cause severe human and animal infection and/or extensive economic losses in animal husbandry. It has been well documented that some Ixodidae ticks are able to transmit Rickettsia, Anaplasma, and Ehrlichia, while the studies on transovarial transmission are limited. In this study, we detected 7 rickettsial species in the cattle tick Rhipicephalus microplus in Hunan Province of the Southern China. Among them, Candidatus Rickettsia xinyangensis and A. platys were also found in the tick eggs and laboratory-hatched larvae of R. microplus, suggesting the vertical transmission of these two pathogens in R. microplus. Our findings provide important information regarding the distribution and ecology of these tick-borne rickettsiae. [ABSTRACT FROM AUTHOR]

Ticks are small, blood-sucking arachnids, known vectors of various diseases, and found throughout the world. They are distributed basically in almost all regions of China. At present, there is not much information regarding tick species on Hainan Island. They were subjected to morphological identification and imaging on an individual basis. Molecular phylogenetic analyses, based on cox1 and 16S rRNA genes, were utilized to identify the species and determine their approximate phylogenetic origin and genetic diversity. The genomic DNA of tick species was extracted, and cytochrome oxidase subunit 1 (cox1) and 16S ribosomal RNA (rRNA) genes were amplified and sequenced. The identification of five tick species, namely Rhipicephalus microplus, Rhipicephalus sanguineus, Rhipicephalus haemaphysaloides, Haemaphysalis cornigera and Haemaphysalis mageshimaensis, was carried out by morphological analysis. When employing the cox1 and 16S rRNA phylogenetic tree, all isolates of R. microplus from Hainan Island were classified as clade A and B, respectively. R. sanguineus was recognized as a member of the tropical lineage by phylogenetic analysis on the cox1 and 16S rRNA genes. Three phylogenetic groups of R. haemaphysaloides were recognized and found to be related closely to strains from China. H. cornigera and H. mageshimaensis formed one phylogenetic group, presumably from tick strains prevalent in Japan and China. The haplotype network analysis indicated that R. microplus is classed into 26 and 6 haplotypes, which correspond to cox1 and 16S rRNA gene assemblages, respectively. In addition, four cox1 haplotypes were detected in R. sanguineus. This is the first evidence that suggests genetic diversity, host range and geographical distribution of hard ticks in Hainan Island, China. [ABSTRACT FROM AUTHOR]

Introduction: Ticks and fleas, as blood-sucking arthropods, carry and transmit various zoonotic diseases. In the natural plague foci of China, monitoring of Yersinia pestis has been continuously conducted inMarmota himalayana and other host animals, whereas other pathogens carried by vectors are rarely concerned in the Qinghai-Tibet Plateau. Methods: In this study, we investigated the microbiota of ticks and fleas sampling from M. himalayana in the Qinghai-Tibet Plateau, China by metataxonomics combined with metagenomic methods. Results: By metataxonomic approach based on full-length 16S rDNA amplicon sequencing and operational phylogenetic unit (OPU) analyses, we described the microbiota community of ticks and fleas at the species level, annotated 1,250 OPUs in ticks, including 556 known species and 492 potentially new species, accounting for 48.50% and 41.71% of the total reads in ticks, respectively. A total of 689 OPUs were detected in fleas, consisting of 277 known species (40.62% of the total reads in fleas) and 294 potentially new species (56.88%). At the dominant species categories, we detected the Anaplasma phagocytophilum (OPU 421) and potentially pathogenic new species of Wolbachia, Ehrlichia, Rickettsia, and Bartonella. Using shotgun sequencing, we obtained 10 metagenomic assembled genomes (MAGs) from vector samples, including a known species (Providencia heimbachae DFT2), and six new species affliated to four known genera, i.e., Wolbachia, Mumia, Bartonella, and Anaplasma. By the phylogenetic analyses based on full-length 16S rRNA genes and core genes, we identified that ticks harbored pathogenic A. phagocytophilum. Moreover, these potentially pathogenic novel species were more closely related to Ehrlichia muris, Ehrlichia muris subsp. eauclairensis, Bartonella rochalimae, and Rickettsia limoniae, respectively. The OPU 422 Ehrlichia sp1 was most related to Ehrlichia muris and Ehrlichia muris subsp. eauclairensis. The OPU 230 Bartonella sp1 and Bartonella spp. (DTF8 and DTF9) was clustered with Bartonella rochalimae. The OPU 427 Rickettsia sp1 was clustered with Rickettsia limoniae. Discussion: The findings of the study have advanced our understanding of the potential pathogen groups of vectors in marmot (Marmota himalayana) in the Qinghai-Tibet Plateau. [ABSTRACT FROM AUTHOR]

Ticks and tick-borne pathogens significantly threaten human and animal health worldwide. Haemaphysalis longicornis is one of the dominant tick species in East Asia, including China. In the present study, 646 Ha. longicornis ticks were collected from free-ranging domestic sheep in the southern region of Hebei Province, China. Tick-borne pathogens of zoonotic and veterinary importance (i.e., Rickettsia, Anaplasma, Ehrlichia, Borrelia, Theileria, and Hepatozoon spp.) were detected in the ticks using PCR assays and sequence analysis. The prevalence rates of these pathogens were 5.1% (33/646), 15.9% (103/646), 1.2% (8/646), 17.0% (110/646), 0.15% (1/646), and 0.15% (1/646), respectively. For Rickettsia spp., R. japonica (n = 13), R. raoultii (n = 6), and Candidatus R. jingxinensis (n = 14) were detected for the first time in the province, while several Anaplasma spp. were also detected in the ticks, including A. bovis (n = 52), A. ovis (n = 31), A. phagocytophilum (n = 10), and A. capra (n = 10). A putative novel Ehrlichia spp. was also found with a prevalence of 1.2% in the area. The present study provides important data for effectively controlling ticks and tick-borne diseases in the Hebei Province region of China. [ABSTRACT FROM AUTHOR]

Ticks play a significant role in transmitting arboviruses, which pose a risk to human and animal health. The region of Liaoning Province, China, with abundant plant resources with multiple tick populations, has reported several tick-borne diseases. However, there remains a scarcity of research on the composition and evolution of the tick virome. In this study, we conducted the metagenomic analysis of 561 ticks in the border area of Liaoning Province in China and identified viruses related to known diseases in humans and animals, including severe fever with thrombocytopenia syndrome virus (SFTSV) and nairobi sheep disease virus (NSDV). Moreover, the groups of tick viruses were also closely related to the families of Flaviviridae, Parvoviridae, Phenuiviridae, and Rhabdoviridae. Notably, the Dabieshan tick virus (DBTV) of the family Phenuiviridae was prevalent in these ticks, with the minimum infection rate (MIR) of 9.09%, higher than previously reported in numerous provinces in China. In addition, sequences of tick-borne viruses of the family Rhabdoviridae have first been reported from the border area of Liaoning Province, China, after being described from Hubei Province, China. This research furthered the insight into pathogens carried by ticks in the northeastern border areas of China, offering epidemiological information for possible forthcoming outbreaks of infectious diseases. Meanwhile, we provided an essential reference for assessing the risk of tick bite infection in humans and animals, as well as for exploring into the evolution of the virus and the mechanisms of species transmission. [ABSTRACT FROM AUTHOR]

We identified Yezo virus infection in a febrile patient who had a tick bite in northeastern China, where 0.5% of Ixodes persulcatus ticks were positive for viral RNA. Clinicians should be aware of this potential health threat and include this emerging virus in the differential diagnosis for tick-bitten patients in this region. [ABSTRACT FROM AUTHOR]

Tick-borne infectious diseases pose a serious health threat in certain regions of the world. Emerging infectious diseases caused by novel tick-borne pathogens have been reported that are causing particular concern. Several tick-borne diseases often coexist in the same foci, and a single vector tick can transmit two or more pathogens at the same time, which greatly increases the probability of co-infection in host animals and humans and can lead to an epidemic of tick-borne disease. The lack of epidemiological data and information on the specific clinical symptoms related to co-infection with tick-borne pathogens means that it is not currently possible to accurately and rapidly distinguish between a single pathogen infection and co-infection with multiple pathogens, which can have serious consequences. Inner Mongolia in the north of China is endemic for tick-borne infectious diseases, especially in the eastern forest region. Previous studies have found that more than 10% of co-infections were in host-seeking ticks. However, the lack of data on the specific types of co-infection with pathogens makes clinical treatment difficult. In our study, we present data on the co-infection types and the differences in co-infection among different ecological regions through genetic analysis of tick samples collected throughout Inner Mongolia. Our findings may aid clinicians in the diagnosis of concomitant tick-borne infectious diseases. Author summary: Ticks carry and transmit a variety of pathogens, and their host animals are widely distributed in nature with diverse epidemic links, so that several tick-borne diseases can coexist in the same foci, and even one type of tick or one tick can carry a variety of pathogens at the same time, these factors pose a serious public health threat. In our study, we summarized the regional differences in tick infection and co-infection rates outcomes in all Inner Mongolia of China, and found that pathogen diversity varied with ecogeographic differences such as gobi desert, grassland and forest. A variety of tick-borne bacterial pathogens were identified, with an overall high prevalence rate (61.4% of ticks infected), among infected ticks, 24.3% were co-infected. An unexpected high infection and co-infection rates of ticks collected from the Forest region of eastern Inner Mongolia (sample area 1) was detected. Geographical differences affect tick species and tick-borne pathogens, so the potential threat to humans or animals is also different. In particular, that that knowledge of co-infections is important as they do not just present diagnostic challenges, but the pathogens might play different roles within their respective hosts, thus modulating disease severity. [ABSTRACT FROM AUTHOR]

Lymphocytic choriomeningitis virus (LCMV) is a neglected rodent-borne zoonotic virus in the genus Mammarenavirus and family Arenaviridae, that can cause aseptic meningitis in humans. A recent study identified infectious LCMV in ticks in northeastern (NE) China. To explore the distribution of LCMV, we determined the prevalence and genetically characterized LCMV in ticks in Jilin Province, NE China. Ticks collected in Huadian, Dunhua, and Jiaohe were pooled and LCMV was detected using reverse transcription polymerase chain reaction. The complete genomes of the LCMV-positive pools were amplified and used for phylogenetic analysis. A total of 1679 questing and engorged ticks were collected and divided into 170 pools, including Ixodes persulcatus (5%), Dermacentor silvarum (89%), and Haemaphysalis japonica (6%). Twenty-four pools of D. silvarum (14.9%, 95% CI:9.5-22.3) and three pools of H. japonica (36.3%, 95% CI:9.8-99.5) collected from cattle were LCMV-positive. No I. persulcatus pools were identified as LCMV-positive. Two complete genome sequences (strains JL-DH01 and JL-DH02) were successfully amplified. They had nucleotide identities of 96.4-99.8% with strains JX31, JX14, DH46, and JX4 identified in ticks from Jilin Province. Phylogenetic analysis indicated that JL-DH01 and JL-DH02 clustered with Jilin strains in the same branch and belonged to genotype I. The findings add to the knowledge of the genetic diversity and geographical distribution of LCMV in ticks in NE China. [ABSTRACT FROM AUTHOR]

Background: Ticks are medically important vectors capable of transmitting a variety of pathogens to and between host species. Although the spectrum of tick-borne RNA viruses has been frequently investigated, the diversity of tick-borne DNA viruses remains largely unknown. Methods: A total of 1571 ticks were collected from forests and infested animals, and the diversity of the viruses they harbored was profiled using a DNA-specific virome method. The viromic data were phylogenetically analyzed and validated by PCR assays. Results: Although diverse and abundant prokaryotic viruses were identified in the collected ticks, only eukaryotic DNA viruses with single-stranded circular genomes covering the anelloviruses and circular replication-associated (Rep) protein-encoding single-stranded (CRESS) DNA viruses were recovered from ticks. Anelloviruses were detected only in two tick pools, but CRESS DNA viruses were prevalent across these ticks except in one pool of Dermacentor spp. ticks. Phylogenetic analyses revealed that these tick-borne CRESS DNA viruses were related to viruses recovered from animal feces, tissues and even environmental samples, suggesting that their presence may be largely explained by environmental factors rather than by tick species and host blood meals. Conclusions: Based on the results, tick-borne eukaryotic DNA viruses appear to be much less common than eukaryotic RNA viruses. Investigations involving a wider collection area and more diverse tick species are required to further support this speculation. [ABSTRACT FROM AUTHOR]

Argas persicus (the fowl tick) is a species of soft tick commonly associated with poultry farms. It has a wide geographic distribution and colonizes different climate regions. Morphological identification of A. persicus has been reported worldwide, but genetic data regarding its molecular characterization is limited. The present study provides data for morphological identification and genetic characterization of A. persicus collected from domestic birds in traditional farms from east Algeria (Setif region). Additionally, A. persicus samples originating from Gansu province in China were included for comparative molecular study. In total, 1518 ticks collected from 30 infested farms were examined and morphologically identified as A. persicus. Furthermore, the 14 tick samples obtained from China were morphologically identified as A. persicus. Molecular analysis of 30 ticks from Algeria (one tick from each infested farm) and the 14 Chinese samples based on PCR, sequencing, and phylogenetic analysis of three mitochondrial genetic markers (16S rRNA, 12S rRNA, and cox1) confirmed morphological results where all samples belonged to the A. persicus group. However, phylogenetic analysis showed that all Algerian samples and two Chinese samples belong to A. persicus sensu stricto (s.s.), while the remaining Chinese samples represented A. persicus sensu lato (s.l.) (divergent lineage). The present study confirms the occurrence of A. persicus s.s. both in Algeria and China, as well as provides novel molecular data for a distinct Chinese lineage of A. persicus. [ABSTRACT FROM AUTHOR]

Background: Ticks act as important vectors of infectious agents, and several emerging tick-borne viruses have recently been identified to be associated with human diseases in northeastern China. However, little is known about the tick virome in northeastern China. Methods: Ticks collected from April 2020 to July 2021 were pooled for metagenomic analysis to investigate the virome diversity in northeastern China. Results: In total, 22 RNA viruses were identified, including four each in the Nairoviridae and Phenuiviridae families, three each in the Flaviviridae, Rhabdoviridae, and Solemoviridae families, two in the Chuviridae family, and one each in the Partitiviridae, Tombusviridae families and an unclassified virus. Of these, eight viruses were of novel species, belonging to the Nairoviridae (Ji'an nairovirus and Yichun nairovirus), Phenuiviridae (Mudanjiang phlebovirus), Rhabdoviridae (Tahe rhabdovirus 1–3), Chuviridae (Yichun mivirus), and Tombusviridae (Yichun tombus-like virus) families, and five members were established human pathogens, including Alongshan virus, tick-borne encephalitis virus, Songling virus, Beiji nairovirus, and Nuomin virus. I. persulcatus ticks had significant higher number of viral species than H. japonica, H. concinna, and D. silvarum ticks. Significant differences in tick viromes were observed among Daxing'an, Xiaoxing'an and Changbai mountains. Conclusions: These findings showed an extensive diversity of RNA viruses in ticks in northeastern China, revealing potential public health threats from the emerging tick-borne viruses. Further studies are needed to explain the natural circulation and pathogenicity of these viruses. Author summary: Ticks are important vectors to transmit many infectious agents. In recent years, many novel tick-borne viruses associated with human illness, including Alongshan virus, Songling virus, and Beiji nairovirus, have been identified in northeastern China. It is necessary to conduct routine surveillance of tick-borne viruses in ticks, however, little is known about the tick virome in northeastern China. In this study, we used metatranscriptomics to investigate the virome diversity in four tick species collected from northeastern China. In total, we identified 22 RNA viruses belonging to eight virus families (exclude an unclassified virus). Of these, five members were established human pathogens, eight viruses were of novel species, and six viruses had close relationship with pathogenic tick-borne viruses with potential public health threats. Moreover, we found that the viromes were significantly affected by the tick species and geographical location in the study. These findings revealed an extensive diversity of RNA viruses in ticks in northeastern China, which will lay the foundation for the prevention and control of emerging tick-borne diseases. [ABSTRACT FROM AUTHOR]

Ixodes hunanensis n. sp. (Acari: Ixodidae), is identified based on the morphological characteristics and molecular biological analyses of males and females ex hog badger, Arctonyx collaris Cuvier (Carnivora: Mustelidae) from China. Adults of this new species are similar to those of other species of the subgenus Pholeoixodes Schulze, 1942, from which they can be distinguished by the shape of basis capituli, development of cornua, size of porose areas, shape, and size of spurs on coxae and phylogenetic analyses of the cox1 and 16S rRNA sequences. [ABSTRACT FROM AUTHOR]

Background: In addition to Mycoplasma haemocanis and Candidatus Mycoplasma haematoparvum, a few hemoplasma species that mainly infect other livestock have been detected in dogs. 'Candidatus Mycoplasma haemobos' (Ca. M. haemobos) has been found in a variety of animals in China. The present study was aimed to investigate the occurrence of 'Ca. M. haemobos' infections in dogs and ticks collected from the Henan province, China. Results: Overall, 55 dog blood samples and 378 ticks on skins were collected from anemic and healthy dogs, and these samples were subjected to PCR, sequence analysis, and identification. The results showed that Haemaphysalis longicornis (266) and Rhipicephalus (Boophilus) microplus (112) were the only two parasitic ticks on dogs. Molecular detection revealed that 163 M. haemocanis, 88 'Ca. M. haemobos' and 32 Anaplasma platys positive amplicons could be amplified from dogs, H. longicornis and R. (B.) microplus. In addition, co-infections (M. haemocanis + A. platys and 'Ca. M. haemobos'+ A. platys) could be also detected. Conclusions: To the best of our knowledge, this is the first molecular evidence of 'Ca. M. haemobos' natural infection in dogs and tick species identified as H. longicornis and R. (B.) microplus from China. [ABSTRACT FROM AUTHOR]

The number of parainfluenza virus 5 (PIV5) infection cases has increased worldwide over the past six decades; however, factors underlying this increase remain unclear. PIV5 has been emerging or re‐emerging in humans and animal species. To date, no information is yet available regarding PIV5 infection in arthropod ticks. Here, we successfully isolated tick‐derived PIV5 from the Ixodes persulcatus species designated as HLJ/Tick/2019 in Heilongjiang, China. Phylogenetic analysis revealed that the tick‐derived PIV5 is closely related to subclade 2.2.6, which has become the dominant subtype prevalent in dogs, pigs and wildlife across China. Further experiments to understand the importance of this virus as an infectious vector revealed that a ferret animal model experimentally infected with Tick/HLJ/2019 via the oronasal and ocular inoculation routes developed moderate respiratory distress with pneumonia and neurologic tissue damage from inflammation for the first time. Further surveillance of PIV5 in vectors of viral transmission is necessary to enhance our knowledge of its ecology in reservoirs and facilitate the control of re‐emerging diseases. [ABSTRACT FROM AUTHOR]

Jingmenviruses are a group of viruses identified recently, in 2014, and currently classified by the International Committee on Taxonomy of Viruses as unclassified Flaviviridae. These viruses closely related to flaviviruses are unique due to the segmented nature of their genome. The prototype jingmenvirus, Jingmen tick virus (JMTV), was discovered in Rhipicephalus microplus ticks collected from China in 2010. Jingmenviruses genomes are composed of four to five segments, encoding for up to seven structural proteins and two non-structural proteins, both of which display strong similarities with flaviviral non-structural proteins (NS2B/NS3 and NS5). Jingmenviruses are currently separated into two phylogenetic clades. One clade includes tick- and vertebrate-associated jingmenviruses, which have been detected in ticks and mosquitoes, as well as in humans, cattle, monkeys, bats, rodents, sheep, and tortoises. In addition to these molecular and serological detections, over a hundred human patients tested positive for jingmenviruses after developing febrile illness and flu-like symptoms in China and Serbia. The second phylogenetic clade includes insect-associated jingmenvirus sequences, which have been detected in a wide range of insect species, as well as in crustaceans, plants, and fungi. In addition to being found in various types of hosts, jingmenviruses are endemic, as they have been detected in a wide range of environments, all over the world. Taken together, all of these elements show that jingmenviruses correspond exactly to the definition of emerging viruses at risk of causing a pandemic, since they are already endemic, have a close association with arthropods, are found in animals in close contact with humans, and have caused sporadic cases of febrile illness in multiple patients. Despite these arguments, the vast majority of published data is from metagenomics studies and many aspects of jingmenvirus replication remain to be elucidated, such as their tropism, cycle of transmission, structure, and mechanisms of replication and restriction or epidemiology. It is therefore crucial to prioritize jingmenvirus research in the years to come, to be prepared for their emergence as human or veterinary pathogens. [ABSTRACT FROM AUTHOR]

Background: Ticks (order Ixodida) are ectoparasites, vectors and reservoirs of many infectious agents affecting humans and domestic animals. However, the lack of information on tick genomic diversity leaves significant gaps in the understanding of the evolution of ticks and associated bacteria. Results: We collected > 20,000 contemporary and historical (up to 60 years of preservation) tick samples representing a wide range of tick biodiversity across diverse geographic regions in China. Metagenomic sequencing was performed on individual ticks to obtain the complete or near-complete mitochondrial (mt) genome sequences from 46 tick species, among which mitochondrial genomes of 23 species were recovered for the first time. These new mt genomes data greatly expanded the diversity of many tick groups and revealed five cryptic species. Utilizing the same metagenomic sequence data we identified divergent and abundant bacteria in Haemaphysalis, Ixodes, Dermacentor and Carios ticks, including nine species of pathogenetic bacteria and potentially new species within the genus Borrelia. We also used these data to explore the evolutionary relationship between ticks and their associated bacteria, revealing a pattern of long-term co-divergence relationship between ticks and Rickettsia and Coxiella bacteria. Conclusions: In sum, our study provides important new information on the genetic diversity of ticks based on an analysis of mitochondrial DNA as well as on the prevalence of tick-borne pathogens in China. It also sheds new light on the long-term evolutionary and ecological relationships between ticks and their associated bacteria. [ABSTRACT FROM AUTHOR]

Tick-borne diseases like Rickettsia, Anaplasma and Ehrlichia are widespread infectious zoonoses that threaten the health of both humans and animals worldwide. Ticks and their hosts, such as hedgehogs, can play a crucial role in transmitting tick-borne diseases and the cycle of Rickettsia. To investigate the presence and identity of Rickettsia in hedgehogs and hedgehog-attached ticks in Xuyi County, Southeast China, 114 ticks were collected from 45 hedgehogs captured totally. Via morphological and molecular methods, all these ticks were identified as two species: Haemaphysalis flava (110/114, 96.5%) and Haemaphysalis longicornis (4/114, 3.5%). Rickettsia spp. were genotypically characterized by PCR targeting rrs, gltA, ompA, ompB, and sca4 gene fragments. The prevalence of spotted fever group rickettsiae (SFGR) infection found in hedgehogs and ticks was 17.8% (8/45) and 78.1% (89/114), respectively. Phylogenetic analyses demonstrated that those Rickettsia spp. belong to two species: Rickettsia heilongjiangensis (R. heilongjiangensis XY-1) and a potential new species, Candidatus Rickettsia xuyiensis XY-2. The present study gave the first evidence of R. heilongjiangensis and Candidatus R. xuyiensis in ticks and hedgehogs of Southeast China. Our findings suggest that hedgehogs might be involved in the natural transmission cycle of Rickettsia species. [ABSTRACT FROM AUTHOR]

The increasing prevalence and transmission of tick-borne diseases, especially those emerging ones, have posed a significant threat to public health. Thus, the discovery of neglected pathogenic agents carried and transmitted by ticks is urgently needed. Using unbiased high-throughput sequencing, a novel Orthonairovirus designated as Meihua Mountain virus (MHMV), was identified in bloodsucking ticks collected from cattle and wild boars in Fujian province, Southeastern China. The full-length genome was determined by RT-PCR and RACE. Genomic architecture of MHMV shares typical features with orthonairoviruses. Phylogenetic analyses suggested that MHMV is clustered into the Nairobi sheep disease (NSD) genogroup of the genus Orthonairovirus and is closely related to the Hazara virus. The RdRp, GPC, and N protein of MHMV shares 62.3%-83.5%, 37.1%-66.1%, and 53.4%-77.3% amino acid identity with other NSD genogroup viruses, respectively, representing a novel species. The overall pooled prevalence of MHMV in ticks was 2.53% (95% CI: 1.62%-3.73%, 22 positives of 134 tick pools), with 7.38% (95% CI: 3.84%-12.59%, 11 positives of 18 pools) in Haemaphysalis hystricis, 6.02% (95% CI: 1.85%-14.22%, four positives of eight pools) in H. formosensis, 25.03% (95% CI: 9.23%-54.59%, six positive of eight pools) in Dermacentor taiwanensis, and 0.16% (95% CI: 0.01%-0.72%, one positive of 100 pools) in Rhipicephalus microplus. This study presented the first report of tick-carried Orthonairovirus in Fujian province and highlighted the broad geographic distribution and high genetic diversity of orthonairoviruses in China. [ABSTRACT FROM AUTHOR]

Tick-borne viruses (TBVs) have increasingly caused a global public health concern. This study collected Rhipicephalus ticks in Guangdong, southern China to identify RNA viruses. Meta-transcriptome analysis revealed the virome in Rhipicephalus ticks, resulting in the discovery of 10 viruses, including Lihan tick virus, Brown dog tick phlebovirus 1 and 2 in the family Phenuiviridae, Mivirus and Wuhan tick virus 2 in the family Chuviridae, Wuhan tick virus 1 in the family Rhabdoviridae, bovine hepacivirus in the family Flaviviridae, Guangdong tick quaranjavirus (GTQV) in the family Orthomyxoviridae, Guangdong tick orbivirus (GTOV) in the family Reoviridae, and Guangdong tick Manly virus (GTMV) of an unclassified family. Phylogenetic analysis showed that most of these TBVs were genetically related to the strains in countries outside China, and GTQV, GTOV, and GTMV may represent novel viral species. These findings provided evidence of the long-distance spread of these TBVs in Guangdong, southern China, suggesting the necessity and importance of TBV surveillance. [ABSTRACT FROM AUTHOR]

Tick-borne diseases have become a global health concern in recent decades. Spotted fever group (SFG) rickettsiae have been recognized as important pathogens of human tick-borne diseases worldwide. In this study, Dermacentor everestianus (n = 646) and Haemaphysalis qinghaiensis (n = 172) ticks were collected from yaks (Bos grunniens) in Shiqu county, eastern Tibetan Plateau, China. SFG rickettsiae were identified and characterized in these ticks. A total of 49.9% (408/818) ticks were infected by Rickettsia spp. with infection rates of 58.1% (100/172) and 46.7% (308/646) detected in H. qinghaiensis and D. everestianus ticks, respectively. Furthermore, 95% of Rickettsia spp. were Rickettsia raoultii-like bacteria, and 5% were related to Candidatus Rickettsia longicornii. To the best of our knowledge, this is the first time that SFG rickettsiae infections were firstly reported in Shiqu county for these tick species. Our results indicated that H. qinghaiensis and D. everestianus ticks from Shiqu county became highly infected with a R. raoultii-like bacteria during their feeding process. This observation is alarming because of the zoonotic potentiality of these species. Overall, the present study detected a widespread of R. raoultii-like bacteria in ticks that are considered a serious threat to domestic animals and humans in Shiqu county. The prevalence of R. raoultii-like bacteria in human and wildlife hosts should be further investigated in the future. [ABSTRACT FROM AUTHOR]

Background: Spotted fever group Rickettsia (SFGR), containing various pathogenic Rickettsia spp., poses remarkable negative influences to public health by causing various severe or mild diseases. Information regarding prevalence of SFGR in ticks in Jiangsu province, Eastern China, is still limited and needs urgent investigations. Methods: Hedgehog- and bovine-attached ticks were collected from Jiangsu province, Eastern China. DNA of individual ticks was extracted for nested polymerase chain reaction amplifications targeting gltA, 16S ribosomal RNA (rrs), ompA, ompB, and sca4 genes following with sequencing. SFGR-specific IgG antibodies in sera of local donators were evaluated using ELISA. Results: Overall, 144 (83.2%) of the 173 ticks from hedgehogs and 2 (1.2%) of the 168 ticks from bovine were positive for one of the three identified Rickettsia spp., with significant difference between the two groups (P = 3.6e-52). Candidatus Rickettsia principis (9; 5.2%) and R. heilongjiangensis (135; 78.0%) were detected in Haemaphysalis flava rather than in H. longicornis ticks from hedgehogs. R. heilongjiangensis (1; 0.6%) and Candidatus R. jingxinensis (or Candidatus R. longicornii) (1; 0.6%) were identified in H. longicornis and Rhipicephalus microplus ticks from bovine, respectively. Phylogenetic analysis indicated Candidatus R. jingxinensis belonged to R. japonica subgroup, whereas Candidatus R. principis belonged to a novel subgroup. Higher serological prevalence of spotted fever and SFGR-specific IgG antibody level in humans were observed around the investigated area than in urban areas, without significant difference. Conclusion: Candidatus R. principis and Candidatus R. jingxinensis were identified in Jiangsu province, Eastern China, and fully genetically characterized for the first time. The higher prevalence of SFGR in hedgehogattached ticks as well as the higher SFGR-specific IgG antibody level and seropositive rate in humans around the investigated area suggested that more attention should be paid to SFGR. This pathogen is usually transmitted or harbored by wild animals and ticks. This study provides important epidemiological data for both physicians and public health officers in developing early prevention and control strategies against potential Rickettsia infections and in the preparation of suitable testing and treatment needs for rickettsiosis in the endemic areas. [ABSTRACT FROM AUTHOR]

Background: Haemaphysalis qinghaiensis is a tick species distributed only in China. Due to its ability to transmit a variety of pathogens, including species of the genera Anaplasma, Rickettsia, Babesia, and Theileria, it seriously endangers livestock husbandry. However, the microbial community of the midgut of H. qinghaiensis females collected from yaks and Tibetan sheep has not yet been characterized using metagenomic sequencing technology., Methods: Haemaphysalis qinghaiensis were collected from the skins of yaks and Tibetan sheep in Gansu Province, China. Genomic DNA was extracted from the midguts and midgut contents of fully engorged H. qinghaiensis females collected from the two hosts. Metagenomic sequencing technology was used to analyze the microbial community of the two groups., Results: Fifty-seven phyla, 483 genera, and 755 species were identified in the two groups of samples. The ticks from the two hosts harbored common and unique microorganisms. At the phylum level, the dominant common phyla were Proteobacteria, Firmicutes, and Mucoromycota. At the genus level, the dominant common genera were Anaplasma, Ehrlichia, and Pseudomonas. At the species level, bacteria including Anaplasma phagocytophilum, Ehrlichia minasensis, and Pseudomonas aeruginosa along with eukaryotes such as Synchytrium endobioticum and Rhizophagus irregularis, and viruses such as the orf virus, Alphadintovirus mayetiola, and Parasteatoda house spider adintovirus were detected in both groups. In addition, the midgut of H. qinghaiensis collected from yaks had unique microbial taxa including two phyla, eight genera, and 23 species. Unique microorganisms in the midgut of H. qinghaiensis collected from Tibetan sheep included two phyla, 14 genera, and 32 species. Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that the functional genes of the microbiome of H. qinghaiensis were annotated to six pathways, and the metabolic pathways included 11 metabolic processes, in which the genes involved in carbohydrate metabolism were the most abundant, followed by the genes involved in lipid metabolism., Conclusions: These findings indicate that most of the microbial species in the collected H. qinghaiensis ticks were the same in both hosts, but there were also slight differences. The analytical data from this study have enhanced our understanding of the midgut microbial composition of H. qinghaiensis collected from different hosts. The database of H. qinghaiensis microbe constructed from this study will lay the foundation for predicting tick-borne diseases. Furthermore, a comprehensive understanding of tick microbiomes will be useful for understanding vector competency and interactions with ticks and midgut microorganisms., (© 2024. The Author(s).)

Background: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that was first identified in mainland China in 2009 and has been reported in Zhejiang Province, China, since 2011. However, few studies have focused on the association between ticks, host animals, and SFTS., Objective: In this study, we analyzed the influence of meteorological and environmental factors as well as the influence of ticks and host animals on SFTS. This can serve as a foundational basis for the development of strategic policies aimed at the prevention and control of SFTS., Methods: Data on SFTS incidence, tick density, cattle density, and meteorological and environmental factors were collected and analyzed using a maximum entropy-based model., Results: As of December 2019, 463 laboratory-confirmed SFTS cases were reported in Zhejiang Province. We found that the density of ticks, precipitation in the wettest month, average temperature, elevation, and the normalized difference vegetation index were significantly associated with SFTS spatial distribution. The niche model fitted accurately with good performance in predicting the potential risk areas of SFTS (the average test area under the receiver operating characteristic curve for the replicate runs was 0.803 and the SD was 0.013). The risk of SFTS occurrence increased with an increase in tick density, and the response curve indicated that the risk was greater than 0.5 when tick density exceeded 1.4. The risk of SFTS occurrence decreased with increased precipitation in the wettest month, and the risk was less than 0.5 when precipitation exceeded 224.4 mm. The relationship between elevation and SFTS occurrence showed a reverse V shape, and the risk peaked at approximately 400 m., Conclusions: Tick density, precipitation, and elevation were dominant influencing factors for SFTS, and comprehensive intervention measures should be adjusted according to these factors to reduce SFTS incidence in Zhejiang Province., (© Mingyong Tao, Ying Liu, Feng Ling, Jiangping Ren, Rong Zhang, Xuguang Shi, Song Guo, Jianmin Jiang, Jimin Sun. Originally published in JMIR Public Health and Surveillance (https://publichealth.jmir.org).)

Background: Anaplasma spp., causative agents of anaplasmosis, pose significant a threat to public health and economic losses in livestock farming. Co-infections/co-existence of various Anaplasma spp. may facilitate pathogen interactions and the emergence of novel variants, represent potential dangers to public health and economic losses from livestock farming, and raise challenges of detection and diagnosis. The information regarding co-infection/co-existence of Anaplasma in their vector ticks and wild animals is limited and needs urgent investigation. Methods: Wild hedgehogs and ticks from hedgehogs and cattle were collected from Jiangsu province, Eastern China, and DNA was extracted from hedgehog organs and tick homogenates. Various genera of species-specific polymerase chain reaction (PCR) or nested PCR amplifications targeting 16S ribosomal RNA (rrs), msp4 , or groEL gene coupled with sequencing were conducted to identify Anaplasma spp. Results: Anaplasma phagocytophilum (1, 0.6%), A. marginale (2, 1.2%), A. platys variants xyn10pt-1 (13, 7.7%), xyn21pt-2 (3, 1.8%), and xyn3pt-3 (3, 1.8%), A. bovis variant cwp72bo-1 (12, 7.1%), and a novel Candidatus Cryptoplasma sp. (1, 0.6%) were identified in 168 Haemaphysalis longicornis ticks from cattle. A. platys variant xyn10pt-1 (20, 11.4%) and A. bovis variants cwp72bo-1 (12, 6.9%) and cwp55-36bo-2 (1, 0.6%) were detected in 173 H. flava ticks from hedgehogs. However, only A. bovis variant cwp72bo-1 (15, 46.7%) was identified in 32 Erinaceus amurensis hedgehogs. Various co-existence combinations were found only in ticks. Conclusion: The co-existence of various Anaplasma spp. and variants in H. flava and H. longicornis was detected for the first time in the world. The high infection rate of A. bovis in hedgehogs and its moderate infection rate in their parasitic ticks suggest that Er. amurensis hedgehog could be an important reservoir of A. bovis , rather than A. platys. Horizontal transmission of Anaplasma spp. may exist among different tick species via their shared hosts in the investigated area. This study provided epidemiological data that could be crucial for strategy development for early warning, prevention, and control of potential Anaplasma infections. [ABSTRACT FROM AUTHOR]

Ticks are an important group of arthropod vectors. Ticks pose a profound risk to public health by transmitting many types of microorganisms that are human and animal pathogens. With the development of next-generation sequencing (NGS) technology and viral metagenomics, numerous novel viruses have been discovered in ticks and tick-related hosts. To fully understand the virus spectrum in ticks in the Zhoushan Archipelago of Zhejiang province in China, ticks were collected from Qushan Island, Zhoushan Island, and Daishan Island in the Zhoushan Archipelago in June 2016. NGS performed to investigate the diversity of tick-associated viruses identified 21 viral sequences. Twelve were pathogenic to humans and animals. Trough verification by polymerase chain reaction (PCR) revealed the existence of three tick-associated viruses with extensive homology with Dabieshan, MG22, and Odaw virus. Other NGS-detected sequences that could not be amplified by PCR were highly homologous (92-100%) with known pathogenic viruses that included hepatitis B virus, papillomavirus, and human mastadenovirus C. This is the first study to systematically apply high throughput sequencing technology to explore the spectrum of viruses carried by ticks in the Zhoushan Archipelago. The findings are fundamental knowledge of the diversity of tick-associated viruses in this region and will inform strategies to monitor and prevent the spread of tick-borne diseases. [ABSTRACT FROM AUTHOR]

Borrelia burgdorferi sensu lato (BBSL), the causative agent of Lyme disease, is commonly found in wild and domestic mammals and ticks worldwide. In China, human cases of Borrelia burgdorferi infections have been identified across a wide geographic range including Yunnan Province, but few studies have examined BBSL in reservoirs and vectors in southwestern China. Here we conducted a thorough and broad-range investigation of BBSL in small mammals, domestic mammals, and ticks collected from 159 sample sites across 42 counties in Yunnan Province. DNA was extracted from spleen tissue of small mammals, blood from domestic mammals, and homogenized ticks. Nested PCR targeting the 5S-23S rRNA intergenic spacer gene of BBSL was used for screening, with amplicons sequenced directly and analyzed using a BLAST algorithm. A total of 8,478 samples were collected, which were composed of 5,044 mammals belonging to 68 species, 1,927 livestock belonging to five species, and 1, 507 ticks belonging to 14 species. BBSL was detected in 147 mammals (2.9%) from 30 different species, 20 of which represent the first reported detection in that species. A total of 52 (2.7%) livestock samples were positive for BBSL, with dogs having the highest detection rate (6.3%, 43/687), and 103 ticks (6.8%) tested positive with high prevalence in Ixodes granulatus (44.2%, 23/52) , Haemaphysalis nepalensi (33.3%, 3/9) and Haemaphysalis kolonini (19.0%, 31/163). Sequence analysis revealed six genospecies of BBSL including B. afzelii , B. burgdorferi sensu stricto , B. japonica , B. garinii , B. sinica, and B. valaisiana. Significant differences in prevalence rates of BBSL were observed by species, landscape types, altitude, and season. Our findings indicate a wide distribution of multiple endemic BBSL genospecies based on a large-scale survey within Yunnan, which underline the need to expand surveillance efforts for human in southwestern China. [ABSTRACT FROM AUTHOR]

Despite few human cases of tick-borne encephalitis virus (TBEV), high rates of TBEV seroprevalence were reported among humans and animals in Xinjiang Uygur Autonomous Region in Northwestern China. In this study, the Karshi virus (KSIV) was identified and isolated from Hyalomma asiaticum ticks in Xinjiang. It belongs to the genus Flavivirus of the family Flaviviridae and is closely related to TBEV. KSIV infects cell lines from humans, other mammals and ticks, and causes encephalitis in suckling mice. High minimum infection rates (4.96%) with KSIV were detected among tick groups. KSIV infections have occurred in sheep and marmots, resulting in antibody-positive rates of 2.43 and 2.56%, respectively. We further found that, of the KSIV antibody-positive serum samples from animals, 13.9% had TBEV exposure showing cross-reaction to KSIV, and 11.1% had KSIV infection resulting in cross-reaction to TBEV; 8.3% were likely to have co-exposure to both viruses (or may be infected with one of them and present cross-reactivity with the other). The results revealed a substantial KSIV prevalence among ticks in Xinjiang, indicating exposure of animals to KSIV and TBEV. The findings implied misinterpretation of the high rates of TBEV seroprevalence among humans and animals in previous studies. There is a need to develop detection methods to distinguish KSIV from TBEV and to perform an in-depth investigation of KSIV and TBEV prevalence and incidence in Northwestern China, which would enhance our preparation to provide medical treatment of emerging diseases caused by tick-borne viral pathogens such as KSIV. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Severe fever with thrombocytopenia syndrome (SFTS), caused by the SFTS virus (SFTSV), is an acute infectious disease transmitted by ticks that has recently been identified. There are no reports of epidemic serotypes in Liaoning Province, PR China. The aim of this study was, therefore, to identify genotypes of SFTSV in this province. Methods: In 2019, quantitative PCR testing was performed on 17 patients suspected of being infected with SFTS in Liaoning Province and on 492 ticks from the counties and cities surrounding the patients' residences. Four samples were subjected to virus isolation and whole-genome amplification. Results: Molecular diagnostic results confirmed SFTSV infection in five of the 17 suspected cases of SFTS and in 12 of the 492 ticks, with a prevalence of 2.4%. Four strains of SFTSV were successfully isolated from patients' blood and ticks. Phylogenetic analysis after whole-genome amplification and sequencing showed that they all belonged to genotype A of SFTSV. Conclusions: This study is the first to determine the genotype of SFTSV in patients and ticks in Liaoning Province, PR China. The results deepen our understanding of the SFTS epidemic and provide information on the variability in mortality rate among genotypes. [ABSTRACT FROM AUTHOR]

• We discovered 10 tick-borne diseases in Rhipicephalus ticks collected from various hosts on Hainan Island, China, using metagenomic next-generation sequencing (mNGS) and polymerase chain reaction (PCR). • Revealed the predominant bacterial phylum (Bacteroidota) and family (Muribaculaceae) in Rhipicephalus spp., enhancing our understanding of tick-associated microbiota. Illumina NovaSeq sequencing showed a unique dominance of Bacteroidota in Rhipicephalus spp. • Identified dual and triple co-infections in R. microplus, R. haemaphysaloides , and R. linnaei , highlighting the complex relationships among tick-borne diseases and complicating our knowledge of these diseases. • Reported the first observations of Anaplasma sp., A. marginale, R. felis , and Coxiella sp. in R. haemaphysaloides on Hainan Island, expanding our understanding of regional tick-borne disease dynamics. • Emphasized the importance of studying tick-associated microbial communities to formulate effective strategies for controlling and preventing tick-borne diseases in the area. The study provides crucial insights into microbial communities and pathogens in Rhipicephalus spp. Ticks are small and adaptable arachnid ectoparasites and global carriers of various pathogens that threaten both human and animal health. They are present in many parts of China. A total of 858 ticks were collected from various regions and hosts, then subjected to species identification based on morphological and molecular characteristics, as described in the authors' previous study. Eighty-three individual tick samples were selected for screening pathogens based on metagenomic next-generation sequencing (mNGS) and polymerase chain reaction (PCR) assays. The genomic DNA of tick species was extracted, and amplification of the bacterial 16S rRNA gene was carried out from DNA of individual ticks using V3-V4 hypervariable regions, before subjecting to metagenomic analysis. Each tick underwent specific PCR tests for identifying the bacterial species present, including Anaplasma, Ehrlichia, Coxiella , and Rickettsia , and also protozoans such as Babesia, Theileria , and Hepatozoon. Illumina NovaSeq sequencing results revealed that the dominant phylum and family in Rhipicephalus spp. were Bacteroidota and Muribaculaceae, respectively. Alpha diversity patterns varied depending on tick sex (R. linnaei only), species and location, but not on host. Furthermore, bacterial pathogens, including A. marginale (58 %, 29/50), A. platys (6 %, 3/50), E. minasensis (2 %, 1/50), Ehrlichia sp. (10 %, 5/50), T. sinensis (24 %, 12/50), T. orientalis (54 %, 27/50) and Coxiella -like bacteria (CLB) (80 %, 40/50) were detected in R. microplus , while E. canis (33.33 %, 10/30), H. canis (20 %, 6/30) and CLB (100 %, 30/30) were detected in R. linnaei. Also, Anaplasma sp. (33.33 %, 1/3), A. marginale (33.33 %, 1/3), R. felis (33.33 %, 1/3) and CLB (100 %, 3/3) were detected in R. haemaphysaloides. Dual and triple co-infections involving pathogens or CLB were detected in 84.00 % of R. microplus , 66.66 % of R. haemaphysaloides , and 33.00 % of R. linnaei. The report on microbial communities and pathogens, which found from Rhipicephalus spp. in Hainan Island, is an important step towards a better understanding of tick-borne disease transmission. This is the first report in the area on the presence of Anaplasma sp., A. marginale, R. felis and Coxiella , in R. haemaphysaloides. [Display omitted] [ABSTRACT FROM AUTHOR]