China has achieved remarkable progress toward eliminating schistosomiasis, yet potential risks persist due to residual snail habitats, animal reservoirs, and uneven surveillance coverage. This paper synthesizes current surveillance frameworks and recent literature to identify key challenges and propose actionable directions for sustaining elimination achievements. It emphasizes the need to distinguish serological evidence of past exposure from active infection when interpreting surveillance results. To consolidate elimination outcomes, we recommend a phased, evidence-based strategy: (1) strengthen integrated human–animal–environment surveillance systems, (2) enhance data sharing and cross-sectoral coordination under the One Health framework, and (3) develop long-term mechanisms for resource allocation and emergency response in re-emergence areas. These recommendations aim to guide policy refinement and prioritize resource investment for sustainable schistosomiasis control in the post-elimination era.

The prevalence and infectious intensity of schistosomiasis japonica has decreased significantly in China in the past few decades. However, more accurate and sensitive diagnostic methods are urgently required for the further control, surveillance, and final elimination of the disease. In this study, we assessed the diagnostic efficacy of a real-time fluorescence quantitative PCR (qPCR) method and recombinase polymerase amplification (RPA) combined with a lateral-flow dipstick (LFD) assay for detecting early infections of Schistosoma japonicum and different infection intensities. The sensitivity of the qPCR at 40 days post-infection (dpi) was 100% (8/8) in mice infected with 40 cercariae, which was higher than in mice infected with 10 cercariae (90%, 9/10) or five cercariae (77.8%, 7/9). The results of the RPA–LFD assays were similar, with sensitivities of 55.6% (5/9), 80% (8/10), and 100% (8/8) in mice infected with 5, 10, and 40 cercariae, respectively. In goats, both the qPCR and RPA–LFD assays showed 100% (8/8) sensitivity at 56 dpi. In the early detection of S. japonicum infection in mice and goats with qPCR, the first peak in positivity appeared at 3–4 dpi, when the positivity rate exceeded 40%, even in the low infection, intensity mice. In the RPA–LFD assays, positive results first peaked at 4–5 dpi in the mice, and the positivity rate was 37.5% in the goats at 1 dpi. In conclusion, neither of the molecular methods produced exceptional results for the early diagnosis of S. japonicum infection. However, they were useful methods for the regular diagnosis of schistosomiasis in mice and goats.

The prevalence of schistosomiasis japonica in China is now characterized by a low epidemic rate and low-intensity infections. Some diagnostic methods with high sensitivity and specificity are urgently needed to better monitor this disease in the current situation. In this study, the detection efficacy of a real-time fluorescent quantitative PCR (qPCR) assay was assessed for schistosomiasis japonica in mice, and before and after treatment with praziquantel (PZQ). Our results showed that the sensitivity of the qPCR was 99.3% (152/153, 95% CI: 96.41-99.98%) and its specificity was 100% (77/77, 95% CI: 95.32-100%) in mice infected with different numbers of Schistosoma japonicum. After the oral administration of PZQ, mice infected with 10 cercariae or 40 cercariae were all Schistosoma japonicum-negative 6 weeks after treatment. However, the negativity rates on a soluble egg antigen (SEA)-based enzyme-linked immunosorbent assay (ELISA) were only 34.8% (8/23, 10 cercariae group) and 6.7% (1/15, 40 cercariae group) at the sixth week after PZQ treatment. These results demonstrated that the qPCR method had good sensitivity and specificity, and suggested that its sensitivity correlated with the infection intensity in mice. Moreover, this method had better potential utility for evaluating the treatment efficacy of PZQ in schistosome-infected mice than SEA-based ELISA.

Stem vascular cambium cells in forest trees produce wood for materials and energy. WOX4 affects the proliferation of such cells in Populus. Here we show that PtrWOX4a is the most highly expressed stem vascular-cambium-specific (VCS) gene in P. trichocarpa, and its expression is controlled by the product of the second most highly expressed VCS gene, PtrVCS2, encoding a zinc finger protein. PtrVCS2 binds to the PtrWOX4a promoter as part of a PtrWOX13a-PtrVCS2-PtrGCN5-1-PtrADA2b-3 protein tetramer. PtrVCS2 prevented the interaction between PtrGCN5-1 and PtrADA2b-3, resulting in H3K9, H3K14 and H3K27 hypoacetylation at the PtrWOX4a promoter, which led to fewer cambium cell layers. These effects on cambium cell proliferation were consistent across more than 20 sets of transgenic lines overexpressing individual genes, gene-edited mutants and RNA interference lines in P. trichocarpa. We propose that the tetramer-PtrWOX4a system may coordinate genetic and epigenetic regulation to maintain normal vascular cambium development for wood formation.

Praziquantel (PZQ) is the first line drug for the treatment of schistosomiasis. Several studies have confirmed that PZQ regulates host immunity, and we have recently found that pretreatment with PZQ enhances resistance against Schistosoma japonicum infection in buffaloes. We speculate that PZQ induces physiological changes in mice that prevent S. japonicum infection. To test this hypothesis and provide a practical measure to prevent S. japonicum infection, we determined the effective dose (the minimum dose), protection period and onset time of protection by comparing the worm burden, female worm burden and egg burden in PZQ-pretreated mice and blank control mice. Morphological differences between parasites were observed by measuring the total worm length, oral sucker, ventral sucker and ovary. The levels of cytokines, nitrogen monoxide (NO), 5-hydroxytryptamine (5-HT) and specific antibodies were measured using kits or soluble worm antigens. Hematological indicators on day 0 were analyzed in mice that received PZQ on days -15, -18, -19, -20, -21 and -22. The PZQ concentrations in plasma and blood cells were monitored using high performance liquid chromatography (HPLC). The effective dose was found to be two oral administrations (interval of 24 h) at 300 mg/kg body weight (BW) or one injection at 200 mg/kg BW, and the protection period of PZQ injection was 18 days. The optimal preventive effect was observed at two days post-administration, with a >92% worm reduction rate and significant worm reduction until 21 days after administration. Adult worms from PZQ-pretreated mice were runtish showing a shorter length, smaller organs and fewer eggs in the uteri of females. Detection of cytokines, NO, 5-HT and hematological indicators showed that PZQ induced immune-physiological changes, including higher levels of NO, IFN-γ and IL-2, and a lower level of TGF-β. No significant difference in the anti-S. japonicum specific antibody levels was observed. The PZQ concentrations in plasma and blood cells 8 and 15 days post-administration were lower than the detection limit. Our results confirmed that pretreatment with PZQ promotes the protection of mice against S. japonicum infection within 18 days. Although we observed some immune-physiological changes in the PZQ-pretreated mice, the exact mechanisms involved in the preventive effect require further study.

Drought has severe effects on plant growth, forest productivity, and survival throughout the world. Understanding the molecular regulation of drought resistance in forest trees can enable effective strategic engineering of novel drought-resistant genotypes of tree species. In this study, we identified a gene, PtrVCS2, encoding a zinc finger (ZF) protein of the ZF-homeodomain transcription factor in Populus trichocarpa (Black Cottonwood) Torr. & A. Gray. ex Hook. Overexpression of PtrVCS2 (OE-PtrVCS2) in P. trichocarpa resulted in reduced growth, a higher proportion of smaller stem vessels, and strong drought-resistance phenotypes. Stomatal movement experiments revealed that the OE-PtrVCS2 transgenics showed lower stomata apertures than wild-type plants under drought conditions. RNA-seq analysis of the OE-PtrVCS2 transgenics showed that PtrVCS2 regulates the expression of multiple genes involved in regulation of stomatal opening and closing, particularly the PtrSULTR3;1-1 gene, and several genes related to cell wall biosynthesis, such as PtrFLA11-12 and PtrPR3-3. Moreover, we found that the water use efficiency of the OE-PtrVCS2 transgenic plants was consistently higher than that of wild type plants when subjected to chronic drought stress. Taken together, our results suggest that PtrVCS2 plays a positive role in improving drought adaptability and resistance in P. trichocarpa.

为了探讨日本血吸虫抗增殖蛋白1(SjPHB1)的免疫保护潜力,应用PCR技术扩增SjPHB1基因,克隆至pMD19-T克隆载体,对其进行测序及生物信息学分析;然后构建pET32a(+)-SjPHB1重组表达质粒,转化至大肠杆菌BL21(DE3)感受态细胞,对重组菌进行鉴定、诱导表达,并纯化重组蛋白;再利用Western blot检测重组蛋白的反应原性;最后以小鼠为动物模型,评估重组蛋白抗日本血吸虫病的免疫保护效果.结果显示:SjPHB1基因ORF序列为825 bp,编码274个氨基酸,具有2个优势辅助T细胞抗原表位和6个优势B细胞抗原表位;rSjPHB1以包涵体的形式表达,分子量约为47kDa,能被anti-His的小鼠血清、人工感染日本血吸虫的小鼠阳性血清特异性识别,表明获得正确表达;该重组蛋白能被免疫小鼠血清识别,具有良好的反应原性;rSjPHB1刺激小鼠产生了较高水平的特异性IgG抗体,但未诱导产生显著的减虫率和肝脏减卵率.本研究结果为进一步探讨SjPHB1基因的生物学特性提供了基础.

The tegument of schistosomes is the interface between the worm and the host environment. Some molecules distributed on the tegument participate in host-parasite interactions. Aspartyl aminopeptidase (AAP), identified on the tegument of Schistosoma japonicum (S. japonicum), facilitate protein turnover by acting in concert with other aminopeptidases. In this study, the gene encoding S. japonicum aspartyl aminopeptidase (SjAAP) was cloned, expressed and characterized. Quantitative real-time PCR analysis showed that SjAAP was expressed in all studied developmental stages. The transcript level was higher in 8, 14, 21, and 28 days old worms than the other detected stages. Moreover, the level of expression in 42-day-old male worms was significantly higher than that in females. The recombinant SjAAP (rSjAAP) was expressed as both supernatant and inclusion bodies in Escherichia coli BL21 cells. The enzymatic activity of rSjAAP was 4.45 U/mg. The Km and Vmax values for H-Asp-pNA hydrolysis were discovered to be 5.93 mM and 0.018 mM.min(-1). Immunofluorescence analysis revealed that SjAAP is primarily distributed on the tegument and parenchyma of schistosomes. Western blot showed that rSjAAP possessed good immunogenicity. Although specific antibodies were produced in BALB/c mice vaccinated with rSjAAP emulsified with ISA 206 adjuvant, no significant reduction of worm burden and number of eggs in the liver was observed. Therefore, rSjAAP may not be suitable to act as a potential vaccine candidate against schistosomiasis japonica in mice. However, this study provides some foundation for further exploration of the biological function of this molecule.

The microRNA‐124‐3p plays an important role in regulating development and neurogenesis. Previous microRNA sequencing analyses of Schistosoma japonicum revealed sja-miR-124-3p differential expression patterns in schistosomes from different hosts and at different developmental stages. This study explores the regulatory role of sja-miR-124-3p in S. japonicum development and reproduction. Quantitative reverse-transcription PCR (qRT-PCR) showed that the expression level of sja-miR-124-3p in S. japonicum from resistant hosts, such as Microtus fortis , and unsuitable hosts, such as rats and water buffalo, was significantly higher than that in mice and yellow cattle at the same developmental stage. Overexpressing sja-miR-124-3p in infected mice led to a hepatic egg reduction rate of 36.97%, smaller egg granulomas in the livers, increased liver weight, subsided hepatocyte necrosis, and diminished inflammatory cell infiltration. The width of female worms increased but decreased in males. The vitelline cells were irregular, swollen, or fused. The teguments and ventral sucker of males and females were swollen and broken, but the morphological changes were particularly notable in males. qRT-PCR and dual-luciferase reporter assay system were used to confirm the in-silico -predicted target genes, S. japonicum DEAD-box ATP-dependent RNA helicase 1 ( sjDDX1 ) and DNA polymerase II subunit 2 ( sjPOLE2 ). Our results showed that RNA interference (RNAi)-mediated sjDDX1 silencing in mice provided a 24.55% worm reduction rate and an 18.36% egg reduction rate, but the difference was not significant ( p > 0.05). Thus, our findings suggest that sja-miR-124-3p has an important role in growth, development, and reproduction in S. japonicum . All these results will greatly contribute toward providing important clues for searching vaccine candidates and new drug targets against schistosomiasis.

为建立一种东方田鼠腹腔巨噬细胞体外分离培养的简便方法,本研究应用DMEM灌洗东方田鼠腹腔后快速水平振荡,分离培养并贴壁筛选纯化巨噬细胞,利用HE染色和墨汁吞噬试验鉴定细胞,通过细胞内酸性磷酸酶及α-醋酸奈酚酯酶染色鉴定细胞活性.结果显示:获得了大量高纯度的腹腔巨噬细胞,细胞形态正常,活细胞比例为98％,细胞培养3 d后具有良好的吞噬功能,胞质内含有较丰富的水解酶.结果表明,快速震荡法是简易实用的东方田鼠腹腔巨噬细胞分离培养方法,为研究巨噬细胞在抗性机制中的作用提供了基础.

目的 克隆、表达 日本血吸虫(Schistosoma japonicum,S.japonicum)带电多泡体蛋白5(CHMP5),并对其生物学特性进行研究.方法 利用PCR扩增S.japonicum CHMP5基因 目的片段,构建重组质粒pET28a(+)-CHMP5,并对该基因进行生物信息学分析.利用荧光定量PCR检测CHMP5在不同时期虫体中的转录水平.对体外表达的重组CHMP5蛋白进行纯化与质谱鉴定,并通过Western blotting检测其反应原性.利用免疫组化实验分析CHMP5在虫体中的分布.以小鼠为动物模型,评估重组CHMP5蛋白抗日本血吸虫病的免疫保护效果.结果 S.japonicum CHMP5的开放阅读框为675 bp,编码224个氨基酸,具有6个B细胞抗原表位;主要定位于S.japonicum虫体的体被上.CHMP5基因在35 d和42 d虫体中的转录水平高于其它检测时期,且42 d雌虫中的转录水平约是42 d雄虫的3倍.克隆表达的重组CHMP5蛋白其理论分子量约为29 kDa,具有较好的反应原性;用其免疫小鼠24 d,即可使小鼠产生较高水平的IgG抗体,并最终诱导产生18.96％的减虫率和42.98％的肝脏减卵率.结论 成功克隆、表达了 S.japonicum体被蛋白CHMP5,其在不同发育时期虫体中均有表达,获得的重组CHMP5蛋白可诱导小鼠产生部分的免疫保护效果,为深入探讨S.japonicum CHMP5的生物学功能提供了基础.

为研究日本血吸虫PROHIBITIN的生物特性,利用PCR和3'RACE扩增到日本血吸虫抗增殖蛋白2(Schistosoma japonicum Prohibitin 2,SjPHB2)基因,构建重组表达质粒pGEX-4T-1-SjPHB2,并在大肠杆菌(E.coli)中诱导表达,用Western blot检测其免疫原性.将重组蛋白免疫小鼠评估其免疫保护效果,ELISA检测其特异性抗体水平.结果显示:日本血吸虫SjPHB2基因编码299个氨基酸,含PHB结构域;含GST标签的rSjPHB2融合蛋白的分子量为59 kDa;rSjPHB2能被GST单克隆抗体抗和免疫血清识别,表明其具有较好的免疫原性;将rSjPHB2结合ISA206佐剂免疫BALB/c小鼠可诱导较高水平的特异性IgG抗体,但未能诱导显著的减虫率和减卵率.本文结果为开展日本血吸虫SjPHB2的表达特性和生物学功能提供了基础.

•The diagnostic method for schistosomiasis control in China is introduced.•Many different diagnostic methods in S. japonicum were analyzed and compared.•New diagnostic strategies need to be studied in the future.

Background N-acetyltransferase 13 (NAT13) is a probable catalytic component of the ARD1A-NARG1 complex possessing alpha (N-terminal) acetyltransferase activity. Results In this study, a full-length complementary DNA (cDNA) encoding Schistosoma japonicum NAT13 (SjNAT13) was isolated from schistosome cDNAs. The 621 bp open reading frame of SjNAT13 encodes a polypeptide of 206 amino acids. Real-time PCR analysis revealed SjNAT13 expression in all tested developmental stages. Transcript levels were highest in cercariae and 21-day-old worms, and higher in male adult worms than female adult worms. The rSjNAT13 protein induced high levels of anti-rSjNAT13 IgG antibodies. In two independent immunoprotection trials, rSjNAT13 induced 24.23% and 24.47% reductions in the numbers of eggs in liver. RNA interference (RNAi) results showed that small interfering RNA (siRNA) Sj-514 significantly reduced SjNAT13 transcript levels in worms and decreased egg production in vitro. Conclusions Thus, rSjNAT13 might play an important role in the development and reproduction of schistosomes.

Although the prevalence of schistosomiasis japonica has declined gradually in China, more accurate and sensitive diagnostic methods are urgently needed for the prevention and control of this disease. Molecular diagnostic methods are advantageous in terms of sensitivity and specificity, but they are time-consuming and require expensive instruments and skilled personnel, which limits their application in low-resource settings. In this study, an isothermal DNA amplification assay and recombinase polymerase amplification (RPA) combined with lateral flow dipstick (LFD) were set up. It was used to detect S. japonicum infections in experimental mice and domestic goats by amplifying a specific DNA fragment of S. japonicum. The lower limit of detection for the LFD-RPA assay was evaluated using dilutions of plasmid containing the target sequence. Cross-reactivity was evaluated using genomic DNA from eight other parasites. The effectiveness of the LFD-RPA assay was verified by assessing 36 positive plasma samples and 36 negative plasma samples from mice. The LFD-RPA assay and real-time PCR were also used to assess 48 schistosomiasis japonica-positive plasma samples and 53 negative plasma samples from goats. The LFD-RPA assay could detect 2.6 femtogram (fg) of S. japonicum target DNA (~39 fg genomic DNA of S. japonicum), only 10-fold less sensitive than real-time PCR assay. There was no cross-reactivity with DNA from the other eight parasites, such as Haemonchus contortus and Spirometra. The whole amplification process could be completed within 15 min at 39°C, and the results can be observed easily using the LFD. The sensitivity and specificity of the LFD-RPA assay were 97.22% (35/36, 95% CI, 85.47%–99.93%) and 100% (36/36, 95% CI, 90.26%–100%) in mice, and 93.75% (45/48, 95% CI, 82.80%–98.69%) and 100% (53/53, 95% CI, 93.28%–100%) in goats. By comparison, the sensitivity and specificity of real-time PCR were 100% (36/36, 95% CI, 90.26%–100%) and 100% (36/36, 95% CI, 90.26%–100%) for mice, and 97.92% (47/48, 95% CI, 88.93%–99.95%) and 100% (53/53, 95% CI, 93.28%–100%) for goats. The LFD-RPA assay exhibits high sensitivity and specificity for the diagnosis of schistosomiasis japonica, and it is an alternative method for diagnosis schistosomiasis japonica in low resource setting.

蛋白是基因功能的主要体现者和具体实施者.近年来,日本血吸虫蛋白质组学研究受到关注并取得一些进展.本文对国内外在日本血吸虫蛋白质组学方面的研究进展作一综述,以期为阐述日本血吸虫的生长发育机制,筛选诊断抗原标识、疫苗候选分子和新治疗药物靶标等提供有参考价值的信息.

In the past decade, ecological surveys emphasized rats and dogs as the most significant animal reservoirs for Schistosoma japonicum (S.j) in the Philippines. However, recent studies demonstrated 51–91% prevalence of schistosomiasis among water buffalo using qPCR in the Sj endemic regions in the Philippines. In order to resolve the inconsistency of reported surveys regarding Sj endemicity among carabao, a domestic water buffalo that is the most important draught animal, we introduced 42 schistosome negative water buffalo to Macanip, Jaro municipality, Leyte, the Philippines, a subsistence rice-farming village that has been the focus of schistosomiasis japonica studies of our group for the past 20 years. We conducted perfusion to the remaining 34 buffalo that survived 10 months of nature exposure and Typhoon Haiyan. Thirty-three water buffalo were found to be positive with at least 1 pair of worms from the mesenteric vein. The infection rate is 97%, with the worm burden of 94 (95% confidence interval, 49–138 worms) worms. To our knowledge, this is the first report about S. japonicum worm burden in naturally infected water buffalo in the Philippines. The fact that with less than one-year of exposure, in this human schistosomiasis endemic area, only 1 out of 34 water buffalo was uninfected is striking. Urgent attention is needed for a cost-effective technique for monitoring Sj infection in animals and humans. Meanwhile, intervention implementation, including water buffalo treatment and vaccination, should be taken into consideration.

Currently the diagnosis of schistosomiasis is mainly determined by observing the presence of eggs in host stool samples. Because of the overwhelming number of impurities in the stool, eggs are rarely observed. Therefore, the stool hatching method is used to observe the miracidia in the water. However, the miracidia of Schistosoma japonicum are small and difficult to detect, and missed detection is likely to occur when the infection level is low. In this study, recombinant streptococcal protein G-enhanced green fluorescent protein (rSPG-EGFP) was expressed, purified, and used as a fluorescence staining reagent for miracidia. A preliminary miracidium fluorescence staining method based on antigen and antibody bindingwas established by combining recombinant protein staining with the stool hatching method. The stool hatching method was used to collect the miracidia of S. japonicum, and Schistosoma-positive serum and the recombinant protein were mixed to assess the feasibility of fluorescence staining of miracidia. The miracidia of S. japonicum and Schistosoma turkestanicum were incubated with S. japonicum-positive serum and S. turkestanicum-positive serum, respectively, to identify miracidia species. When the fluorescence staining method was used to observe living miracidia, the miracidiawere labelled by the recombinant protein, and their motility status was not affected.

Microtus fortis is the only mammalian host that exhibits intrinsic resistance against Schistosoma japonicum infection. However, the underlying molecular mechanisms of this resistance are not yet known. Here, we perform the first de novo genome assembly of M. fortis, comprehensive gene annotation analysis, and evolution analysis. Furthermore, we compare the recovery rate of schistosomes, pathological changes, and liver transcriptomes between M. fortis and mice at different time points after infection. We observe that the time and type of immune response in M. fortis are different from those in mice. M. fortis activates immune and inflammatory responses on the 10th day post infection, such as leukocyte extravasation, antibody activation, Fc-gamma receptor-mediated phagocytosis, and the interferon signaling cascade, which play important roles in preventing the development of schistosomes. In contrast, an intense immune response occurrs in mice at the late stages of infection and could not eliminate schistosomes. Infected mice suffer severe pathological injury and continuous decreases in cell cycle, lipid metabolism, and other functions. Our findings offer new insights into the intrinsic resistance mechanism of M. fortis against schistosome infection. The genome sequence also provides the basis for future studies of other important traits in M. fortis.