Jia-Fu Jiang

Ticks, which are globally distributed, transmit a wide range of human and animal pathogens. Soft and hard ticks are two major tick families exhibiting distinct vector capacities and blood-feeding abilities. However, understanding the genetic basis of these differences is hindered by the scarcity of high-quality tick genomes, particularly for soft ticks. Here, we present high-quality genomes of two soft and two hard tick species of both evolutionary and medical importance, and compare the genomic characteristics of the two tick families. Compared with soft ticks, hard ticks exhibited faster genome evolution, characterized by larger genome sizes, higher rates of gene gain and loss, and a greater number of positively selected genes. Both tick families exhibited frequent positive selection across metabolism and organismal systems, sharing a core set of adaptive genes but undergoing refinement at different sites. Gene families underpinning various vector capacities, including those involved in cuticle structure, heme biosynthesis, egg waxing, and immune pathways, were identified. Additionally, we assembled the genomes of two novel Rickettsia endosymbionts from soft ticks, revealing high genomic divergence and lineage-specific adaptations to their hosts. These genomic resources provide fundamental insights into the genetic basis of tick biology and vector capacity, highlighting the divergent evolutionary strategies of blood-feeding arthropods shaped by their ecological niches.

Malaria pathogenesis involves complex immunopathological mechanisms that hinder early diagnosis and effective treatment. This study integrates multi-omics data and experimental models to identify host-derived biomarkers and elucidate their functional roles. By combining human transcriptomic datasets, weighted gene co-expression network analysis (WGCNA), and machine learning (LASSO, SVM, RF), we identified C1QB as a key hub gene. In human data, C1QB was significantly upregulated in both training and validation cohorts (AUC 0.983 and 0.970). Single-gene GSEA and immune infiltration analyses linked C1QB to apoptosis, inflammation, and altered immune cell composition, including increased activated dendritic cells and neutrophils, and decreased naïve B cells and CD8⁺ T cells. In a murine malaria model (Plasmodium berghei ANKA), C1QB expression rose as early as day one post-infection, preceding detectable parasitemia. Immunohistochemistry revealed C1QB accumulation in the liver and spleen. Single-cell RNA sequencing in the murine model confirmed monocyte-predominant expression, and scTenifoldKnk analysis suggested its role in immune regulation. Crucially, inhibiting C1q in mice via antibody intervention alleviated malaria-induced inflammation, tissue damage, and apoptosis, indicating that C1QB/C1q actively contributes to immunopathology. AI-based drug prediction and molecular docking further supported its therapeutic potential. Collectively, our findings establish C1QB as a dual biomarker and pathogenic driver in malaria, with diagnostic and therapeutic implications. Further studies are required to validate direct target engagement and clarify upstream regulatory mechanisms.

RNA viruses exhibit high mutation rates and strong host adaptive capacity, posing major public health challenges. Although meta-transcriptomic studies have uncovered vast numbers of novel RNA viral sequences, identifying those with spillover risks remains difficult. Current virus host-prediction methods can only predict a narrow set of host labels at coarse taxonomic levels (e.g., kingdom or order), which hampers precise evaluation of cross-species transmission risk and may overlook potential zoonotic hosts. To overcome these limitations, we developed UniVH, a unified virus–host association prediction framework trained on an exceptionally broad spectrum of 90 viral families and 240 host families, enabling robust prediction even for phylogenetically distant or data-scarce hosts. UniVH achieved a host prediction accuracy of 71.2% for novel viruses discovered after 2020, representing a 15.3% improvement over conventional BLASTp-based homology approaches. Feature interpretation revealed that viral structural genes and host immune- and metabolism-related genes contributed most significantly to predictive performance. Model predictions indicated widespread host-range expansion, with 20 mammalian virus families doubling their documented mammalian host ranges and several showing marked increases in viruses with human-infection potential. This unified, interpretable framework represents an important methodological advance for future RNA virus spillover-risk evaluation and emerging virus prioritization.

SARS-CoV, MERS-CoV, and SARS-CoV-2 have posed tremendous threats to human health, highlighting the necessity of monitoring cross-species transmission of animal coronaviruses to humans. Hedgehogs infected with coronaviruses have been reported in several countries across Europe and Asia, raising concerns about the potential transmission of coronaviruses from hedgehogs to humans. In this study, we investigated coronavirus infections in hedgehogs inhabiting greenspaces in metropolitan Beijing and identified a Merbecovirus subgenus coronavirus with a prevalence rate of 30% (95% CI: 25–35%) among 317 hedgehogs. Phylogenetic analysis of 23 complete viral genome sequences revealed a monophyletic origin, showing close relatedness to Erinaceus hedgehog coronavirus HKU31 (Ea-HedCoV HKU31) with genome-wide nucleotide identities of 93.24–96.42%, and evidence of recombination with Tylonycteris bat coronavirus HKU4. These findings suggest that the increase in wildlife populations associated with urban greenspace development may pose a potential threat to human health that should not be overlooked.

The Haemaphysalis longicornis tick, an important arthropod vector native to East Asia, has expanded its range to Oceania and the American continents, where populations are exclusively parthenogenetic females. While the parthenogenetic population possesses a stable triploid genetic system, the absence of a triploid genome assembly has prohibited us from understanding their genetic evolution and biological traits. Here, we present a chromosome-level, haplotype-resolved triploid genome assembly of the parthenogenetic population by integrating ultra-deep long-read high-fidelity, short-read high-throughput chromosome conformation capture, and isoform sequencing technologies. The phylogenetic analysis suggested that triploid genome originated from an autopolyploid event rather than interspecific hybridization. We identified functional genes that enable parthenogenetic ticks to complete embryogenesis without fertilization. Parthenogenetic ticks showed higher tolerance to Rickettsia and virus infections, with more differential expressed genes compared to bisexual ticks. They exhibited lower levels of deleterious mutations across the genome and a broader global distribution predicted by ecological niche modeling.

Emerging tick-borne viruses are posing an increasing health concern. However, there is limited knowledge about the distribution characteristics of tick virome in Yunnan Province, southwestern China, where it is distinguished by its diverse eco-climatic zones and rich biodiversity, making it a hotspot for studying tick-borne pathogens. The present study aimed to explore the diversity and ecological characteristics of tick virome in Yunnan Province, especially to identify novel potentially pathogenic viruses threatening human and vertebrate animals, and to investigate host-specific viral tropisms and their transmission characteristics. Using a meta-transcriptomic approach, the study analyzed the viromes of 448 individual ticks and approximately 10,000 eggs, collected from nine counties with different hosts, altitudes and landscapes. The ticks encompassed eight species across four genera. The study focused on delineating virome diversity profiles, evaluating host-specific viral tropisms, and investigating potential transovarial transmission through viral contigs identification and Sanger sequencing. The study identified 53 viral families, revealing significant virome diversity and geographic and environmental specificity. Haemaphysalis and Ixodes ticks exhibited greater viral richness and abundance, with host taxonomy being a primary influencing factor. We determined 102 viral genomes encompassing 35 species, comprising 15 novel viruses identified when their RNA-dependent RNA polymerase/DNA polymerase sequences exhibited <90% amino acid identity to known viruses. The novel vectors for vertebrate-related or potentially pathogenic viruses were also detected, thus providing new insights into transmission cycles. The evidence for transovarial transmission was reinforced by the absence of significant differences in Chuviridae and Nairoviridae families between female ticks and their eggs. These findings underscore the necessity of continuous surveillance to avert the spillover of emerging pathogens.

Theileria luwenshuni and Babesia spp. Infections

Background: Colpodella species are classified within the domain Eukaryota, specifically under the order Colpodellida, family Colpodellaceae, and genus Colpodella, which are close relative of the phylum Apicomplexa. These organisms are unicellular, predatory flagellates. In recent years, their frequent detection in animal tissues, vector insect samples, and particularly in human has garnered significant attention as an emerging zoonotic threat. This review is to scope the biological characteristics and epidemiological features of Colpodella species. Methods: The PubMed, Web of Science, and China National Knowledge Infrastructure databases were searched to identify studies in English or Chinese published before 4 February 2025. We searched for Colpodella-related nucleotide sequences released in the GenBank before 31 December, 2024. The literature and sequences were selected based on predefined inclusion criteria. We extracted the characteristics of Colpodella spp. from included articles and performed a phylogenetic analysis based on the included sequences. Results: Thirty-seven records and 83 sequences were included in the study, respectively. Colpodella spp. currently comprise only two formally named species, alongside at least 11 species uncultured or unnamed in GenBank. Their life cycle includes trophozoite and cyst stages, with nutrient acquisition mediated by myzocytosis. These organisms display structural and protein similarities in their apical complexes to apicomplexan protozoa, yet with distinct differences. They are currently found in a wide range of hosts, including humans, livestock, pets, wildlife and vectors, across multiple continents, including Europe, Asia, Africa, and the Americas. Phylogenetic analyses reveal that Colpodella spp. exhibit significant genetic diversity and can be divided into seven clades, each characterized by distinct host ranges and regional distributions, and three clades posed pathogenic potential and significant risk of human infection. Conclusions: This study systematically elucidates the broad host/vector range, genetic diversity and public health implications of Colpodella species based on comprehensive integrated genomic and epidemiological analyses. We recommend establishing active surveillance networks using clade-specific molecular markers for hosts and vectors in high-risk regions, incorporating Colpodella screening into routine diagnostics for fever cases of unknown origin with anaemia, prioritizing studies on isolation and cultivation, biological characteristics, and clade-specific in vitro invasion assays to elucidate the pathogenic mechanisms. Graphical

Background: Human babesiosis, caused by intraerythrocytic protozoa of the genus Babesia (Piroplasmida, Babesiidae), is a globally emerging zoonosis transmitted primarily through Ixodes spp. ticks. Babesia microti, which is endemic particularly in the northeastern and midwestern United States, accounts for the majority of globally reported human cases. Recent studies highlight its spread to non-traditional regions and cross-border transmission, driven by climate change, blood transfusions and increased human mobility. Despite increasing reports of autochthonous B. microti infections in certain areas of China, imported cases remain critically underrecognized due to overlapping clinical manifestations with malaria and limited diagnostic awareness. Case presentation: We report a diagnostically challenging case of acute B. microti infection in a 52-year-old Chinese woman, presenting with a sudden recurrent fever (39.0–41.0 °C), hemolytic anemia (hemoglobin 104 g/L), thrombocytopenia (platelet 78 × 10⁹ /L) and splenic hypodense lesions on July 11, 2023, seven days after returning from a 14-day visit to rural Wisconsin, United States. Peripheral blood smears demonstrated characteristic intraerythrocytic ring forms (parasitemia: 7800 organisms/μl) and pathognomonic "Maltese cross" tetrads. Polymerase chain reaction (PCR) targeting the 18S rRNA gene confirmed B. microti infection (GenBank No. PP087232), showing 99.8% identity with the US-type strain Gray (AY693840) and the sequence obtained from a US travel-acquired case in Singapore (MK609547). The patient received intravenous clindamycin (600 mg twice daily), oral dihydroartemisinin (80 mg twice daily), packed red blood cell transfusions, and supportive care, ultimately achieving full recovery after 17 days. Conclusions: This study documented the first imported cases of human babesiosis in China, emphasizing the need for heightened clinical and public health vigilance. Screening travelers from endemic areas presenting with fever or hemolytic anemia for Babesia, bolstering molecular diagnosis, improving transfusion safety, and intensifying regional surveillance are crucial in reducing underdiagnosis and preventing transmission. These measures are essential for controlling babesiosis in China. Graphical