In the context of the current low endemicity of schistosomiasis in China, Schistosoma japonicum (S. japonicum) infections increasingly have been reported in field-captured rodents, highlighting the need for rapid and scalable tools to support surveillance during the elimination stage. This study developed and evaluated a quantitative polymerase chain reaction (qPCR) assay targeting a highly repetitive S. japonicum sequence for detecting infection in liver tissues. Analytical performance was assessed using adult-worm genomic DNA, DNA from non-target pathogens, egg-spiked mouse liver samples, experimentally infected BALB/c mice, and liver samples from field-captured rodents collected in Dongzhi and Duchang counties. The optimized assay generated a single melting peak at 79 ± 0.5 °C, used Ct < 33 as the positivity cutoff, and showed no apparent cross-reactivity with the non-target pathogens tested. Using serially diluted adult-worm genomic DNA, the assay consistently detected S. japonicum DNA at concentrations as low as 1 pg/μL. In the egg-spiked liver model, as few as two eggs were detected in 200 mg of liver tissue. In the experimentally infected model, all infected mice tested positive, whereas all non-infected controls tested negative, indicating complete agreement between the qPCR results and the experimentally defined infection status. In the field evaluation, qPCR yielded a higher positivity rate than parasitological examination in Dongzhi County (66.81% vs. 51.72%) and identified six positive samples in Duchang County, where all samples were negative by parasitological examination. These findings indicate that the qPCR assay can facilitate sensitive and high-throughput detection of S. japonicum infection in field-captured rodents and may provide a useful complementary tool for surveillance during schistosomiasis elimination.

Background: The global emergence and dissemination of carbapenem-resistant among Enterobacterales pose a substaintial public‑health threat. However, Escherichia coli (E. coli) sequence type (ST) 3014-including carbapenem-resistant ST3014 strains-remains poorly characterized, with only sporadic reports across several countries at interfaces of human, animal and environment. This research identified the genomic and plasmid features of a carbapenem-resistant ST3014 strains, thus providing reference for researchers and policy-makers for future study and intervention.Methods: A blaNDM-5 ‑harboring E. coli (coded E44) was recovered from one of 60 piglet fecal samples collected from an intensive swine farm in Qionghai City, Hainan Province. The isolates were undergone both short- and long-read sequencing, followed by hybrid assembly and functional annotation. To contextualize its genomic characteristics, a global E. coli ST3014 dataset was compiled from EnteroBase, NCBI, and published literature to assess antimicrobial resistance genes (ARGs), virulence factors (VFs), and core-genome phylogeny. Furthermore, the blaNDM-5 -carrying plasmid from E44 queried against the PIPDB database, and plasmid-level phylogenetic relatedness was inferred using Mash distances. The blaNDM-5 gene cluster of E44 further compared with other plasmids carrying blaNDM-5 to characterize the local genetic environment surrounding this resistance determinant.Results: The blaNDM-5-positive ST3014 isolate carried six ARGs and forty-two virulence factors (VFs), with blaNDM-5 located on a 124-kb IncF multireplicon plasmid. In addition to four other ARGs, this plasmid co-harbored ExPEC-associated siderophore/iron-uptake loci, including sitABCD and iucABCD-iutA. A global dataset comprising 82 ST3014 E. coli isolates demonstrated broad geographic and ecological dissemination across 23 countries, spanning human, animal, and environmental sources. Global phylogenomic and phylogeographic analyses suggested that ST3014 likely originated in Asia (China), with the lineage estimated to have emerged around 1963 and to have spread internationally after 2010. Phylogenetic analysis of 124-kb-like IncF plasmids (152 homologous sequences) indicated that these plasmids are distributed across diverse Enterobacterales hosts, with E. coli as the predominant host; notably, an E. coli-derived blaNDM-5-harboring plasmid was the closest relative of this newly identified plasmid. Comparative analysis of blaNDM-5 genetic contexts further revealed a conserved core module (ble-trpF-dsbD) bracketed by insertion sequences, particularly IS26 and ISAba125.Conclusions: The blaNDM-5 positive ST3014 E. coli isolate presents an emerging threat to the breading industry and food safety due to its global distribution and the presence of a conjugative plasmid carrying clinically relevant VFs and ARGs. Meanwhile, the multi-interface distribution of both bacteria and plasmids underscores the importance of antimicrobial resistance (AMR) surveillance under the One Health framework.

Psittacosis caused by Chlamydia psittaci has re-emerged in China as sporadic cases and localized outbreaks. However, current knowledge remains fragmented across the clinical, veterinary, epidemiological, and public health fields. This scoping review mapped studies on psittacosis in China, identified major knowledge gaps, and defined priorities for research, clinical management, and prevention and control. Following the Arksey and O'Malley framework and Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR), China National Knowledge Infrastructure (CNKI), Wanfang, PubMed, Web of Science, and Embase were searched for studies published between 1 January 1985 and 31 December 2025 and synthesized eligible studies with descriptive statistics and thematic analysis. A total of 424 studies were included. Research interest showed recent sharp increases and was concentrated in Eastern and Central China. Case reports and series dominated the literature, whereas analytic epidemiology, standardized surveillance, and high-resolution molecular studies remained limited. Reported cases were most often documented in middle-aged and older adults with avian exposure, including pet birds and poultry, and the reported occurrence showed a winter-spring pattern. Pneumonia was the predominant clinical presentation, and severe cases could progress to acute respiratory distress syndrome and multi-organ dysfunction. Metagenomic next-generation sequencing (mNGS) was the most frequently reported diagnostic method in recent studies, while PCR and serology remained important complementary tools. Overall, the literature is growing rapidly, but remains uneven in geographic coverage, study design, and integration across human, animal, and environmental sectors. These findings support broader One Health surveillance, stronger analytic and molecular epidemiology, and more standardized approaches to diagnosis, source investigation, and prevention in China.

Angiostrongylus cantonensis (A. cantonensis) is the primary causative agent of human angiostrongyliasis and is widely distributed in Southeast Asia and China, with increasing reports from the Americas. Achatina fulica (A. fulica), Pomacea canaliculata (P. canaliculata), and slugs constitute established intermediate hosts of A. cantonensis, whereas Camaena hainanensis (C. hainanensis) has been newly reported as a host species in Hainan. A TaqMan quantitative PCR (qPCR) method assay targeting a novel genomic region of A. cantonensis was developed to detect infection in 150 snails collected from Hainan Province, China. The assay was employed to detect the parasite larvae across various snail tissues (lung sac, mucus, and foot), and its performance was compared with conventional lung sac microscopy. Out of the 120 A. fulica examined, 75 tested positive using the qPCR assay, yielding a significantly higher detection rate than lung-sac examination (p < 0.05). Significant differences were also observed in the positivity rates across the three snail tissues (lung sac, mucus, and foot) (p < 0.05), with the lung sac showing the highest rate of infection. Importantly, the detection of A. cantonensis DNA in snail mucus highlights its potential for development as a non-invasive diagnostic sample. Additionally, C. hainanensis was identified as a new host of A. cantonensis in Hainan, suggesting its possible contribution to parasite transmission. The newly developed qPCR assay demonstrated superior sensitivity (reflected by lower Ct values) compared with previously published TaqMan qPCR methods. The established qPCR method provides a sensitive and non-invasive tool for detecting A. cantonensis in snails, and can be applied for monitoring and early warning of parasite prevalence and transmission.

Background: Fascioliasis, caused by Fasciola species, is a significant public health concern affecting over 250 million people globally and causing annual economic losses exceeding USD 6 billion. The sole FDA-approved treatment, triclabendazole (TCZ), faces increasing resistance due to extensive use, highlighting the urgent need for alternative therapeutic targets. A promising candidate is thioredoxin glutathione reductase (TGR), a multifunctional enzyme unique to platyhelminths, essential for redox balance and parasite survival. Methods: This study investigated the antioxidant and enzymatic activities of recombinant Fasciola gigantica TGR (FgTGR), its localization within the parasite, and its inhibition by furoxan derivatives. FgTGRsec (FgTGR containing selenocysteine) was expressed and purified, and its enzymatic activities, including thioredoxin reductase (TrxR), glutathione reductase (GR), and glutaredoxin (Grx), were characterized. Results: Immunolocalization studies revealed FgTGR’s presence in critical tissues, underscoring its functional significance. Antioxidant assays demonstrated the protein’s role in protecting against oxidative damage. Inhibition assays with furoxan derivatives identified potential inhibitors targeting TGR activity. Sequence and phylogenetic analyses showed FgTGR’s evolutionary conservation among trematodes, confirming its potential as a drug target. Conclusions: The study’s findings establish FgTGR as a critical enzyme for parasite survival and a promising target for developing novel therapeutics. These results pave the way for the further screening and optimization of TGR inhibitors, offering a strategic approach to overcoming TCZ resistance and improving fascioliasis control.

Background: Giardia duodenalis is one of the most prevalent protozoan pathogens, commonly infecting a wide range of hosts including humans, livestock, companion animals, and wildlife globally. The Bamaxiang pig (Sus scrofa domesticus), a native livestock variety from China’s Guangxi region, holds significant importance in Bama Yao Autonomous County. This breed not only supports regional meat production systems but also fulfills dual roles as human companions and valuable subjects for biomedical investigations. The aim of present study was to investigate the prevalence of G. duodenalis and assess its genetic characteristics. A total of 311 fresh fecal samples were collected from three farms in Bama Yao Autonomous County. The presence and genetic diversity of G. duodenalis were determined by nested PCR and sequence analysis of the glutamate dehydrogenase (gdh), β-giardin (bg) and triose phosphate isomerase (tpi) genes. Results: The total occurrence rate of G. duodenalis in Bamaxiang Pigs was 17.36% (54/311). Among different age groups, suckling piglets exhibited the highest infection rate at 24.29% (17/70). The infection rates in the sows, fattening pigs, and weaned piglets were 20.88% (19/91), 14.10% (11/78), and 9.72% (7/72), respectively (p < 0.05). Phylogenetic analysis of sequences from three genetic loci identified two G.duodenalis genetic assemblages, namely assemblages A and E. Among them, assemblage A (n = 31) was the predominant genotype across the three farms, followed by the assemblage E (n = 21) and mixed assemblage A/E (n = 2) infections. Conclusions: This study represents the first report demonstrating that G. duodenalis infection is prevalent in Bamaxiang pigs, with variable positivity rates across different growth stages. The zoonotic assemblage A was the predominant assemblage, suggesting a potential risk of transmission to humans through close contact with this specific pig breed. The results provide basic data for controlling infections in Bamaxiang pigs.

Parasitic flatworms of the genus Schistosoma infect a wide range of definitive hosts, which are categorized as permissive or non-permissive based on their capacity to support parasite development. Unlike permissive hosts such as mice, Schistosoma japonicum undergoes pronounced developmental arrest in non-permissive hosts like rats; however, the molecular mechanisms underlying this phenomenon remain largely unclear. In this study, we conducted a comprehensive morphological and transcriptomic comparison of S. japonicum derived from mouse and rat hosts at multiple time points post-infection, identifying the period between 12 and 24 days post-infection (dpi) as a critical window for developmental arrest in parasites from rats. Utilizing single-cell RNA sequencing, we constructed a high-resolution cellular atlas of S. japonicum at 14 and 24 dpi from both host species, revealing host-dependent alterations in cell composition and transcriptional programs during parasite development. Functional analyses further demonstrated that impairments in mitochondrial function and anaerobic glycolysis contribute to the developmental arrest observed in parasites from rats. Additionally, downregulation of ribosomal genes was associated with reduced protein synthesis and impaired cell proliferation. Together, these findings suggest that disruptions in energy metabolism and ribosomal function are key drivers of developmental arrest in non-permissive hosts. This study provides novel, parasite-centered insights into host permissiveness and identifies potential molecular targets for schistosomiasis control strategies. ### Competing Interest Statement The authors have declared no competing interest. National Key Research and Development Program of China, Grant Nos. 2021YFC2300800, Grant Nos. 2021YFC2300803 Fund of Fudan University and Cao'ejiang Basic Research, No.24FCA04

Schistosomiasis is a major neglected tropical disease that lacks an effective vaccine and faces increasing challenges from praziquantel resistance, underscoring the urgent need for novel therapeutics. Target-based drug discovery (TBDD) is a powerful strategy for drug development. In this study, we utilized AlphaFold to predict the structures of target proteins from Schistosoma mansoni and S. japonicum, followed by virtual molecular screening to identify potential inhibitors. Among 202 potential therapeutic targets, we identified 37 proteins with high-accuracy structural predictions suitable for molecular docking with 14,600 compounds. This screening yielded 268 candidate compounds, which were further evaluated ex vivo for activity against both adult and juvenile S. mansoni and S. japonicum. Seven compounds exhibited strong anti-schistosomal activity, with HY-B2171A (Carubicin hydrochloride, CH) emerging as the most potent. CH was predicted to target the splicing factor U2AF65, and knockdown of its coding gene Smp_019690 resulted in a phenotype similar to CH treatment. RNA sequencing revealed that both CH treatment and Smp_019690 RNA interference (RNAi) disrupted splicing events in the parasites. Further studies demonstrated that CH impairs parasite viability by inhibiting U2AF65 function in mRNA splicing regulation. By integrating RNAi-based target identification with structure-based virtual screening, alongside ex vivo phenotypic and molecular analyses of compound-treated schistosomes, our study provides a comprehensive framework for anti-schistosomal drug discovery and identifies promising candidates for further preclinical development.

Orientobilharziasis, caused by Orientobilharzia turkestanicum, is a zoonotic parasitic disease that leads to significant economic losses in livestock and cercarial dermatitis in humans. This study focuses on the molecular characterization and functional analysis of thioredoxin glutathione reductase (TGR) from O. turkestanicum, a key enzyme involved in the parasite’s antioxidant defense system. The full-length O. turkestanicum thioredoxin glutathione reductase (OtTGR) cDNA and O. turkestanicum thioredoxin glutathione reductase with selenocysteine (OtTGRsec) were cloned and expressed as recombinant proteins in E. coli. Western blotting confirmed the specific immunoreactivity of rOtTGR with polyclonal antibodies, and immunohistochemistry revealed its predominant localization on the tegument of adult worms. Enzymatic activity assays demonstrated that rOtTGRsec possesses thioredoxin reductase, glutaredoxin, and glutathione reductase activities, with optimal activity under physiological pH and temperature conditions. RNA interference assays showed that siRNA3 effectively suppressed OtTGR expression in vitro, reducing mRNA levels by 46.1%. These findings highlight the critical role of OtTGR in parasite survival. Comparative with other trematodes, such as Schistosoma japonicum and Fasciola hepatica, suggests that OtTGR may serve as a promising target for vaccine or drug development. Although immune-protective studies were not feasible due to host incompatibility, the conserved role of TGR across trematodes underscores its potential for controlling orientobilharziasis. Future studies will explore the immunogenicity and protective efficacy of OtTGR to assess its candidacy as a therapeutic target.

Blastocystis spp. and Enterocytozoon bieneusi are common intestinal pathogens capable of infecting both humans and animals, which lead to severe diarrhea and other intestinal diseases, posing a threat to public health. The Bamaxiang pig, a specialty of Bama Yao Autonomous County in Guangxi Province, China, is an important local breed in the regional pork market and an excellent model animal for biomedical research. Currently, no data is available on the prevalence or genotype distribution of these pathogens in Bamaxiang pigs. This study aimed to determine the prevalence and genetic characteristics of Blastocystis spp. and E. bieneusi in three Bamaxiang pig farms located in Bama Yao Autonomous County, using molecular techniques based on the small subunit ribosomal RNA (SSU rRNA) gene fragment of Blastocystis spp. and the internal transcribed spacer (ITS) region of E. bieneusi. All positive PCR products from the 311 fecal samples were sequenced to identify the species and genotypes of these organisms. The overall infection rates of Blastocystis spp. and E. bieneusi were 34.08% (106/311) and 18.32% (57/311), respectively. Three subtypes of Blastocystis spp. were detected: ST1 (n = 8), ST3 (n = 3), and ST5 (n = 95). Among them, zoonotic ST5 was the dominant genotype, accounting for 89.62% (95/106) of strains, followed by the genotypes ST1 (7.54%, 8/106) and ST3 (2.83%, 3/106). Two genotypes of E. bieneusi were detected: EbpC (n = 52) and CHG23 (n = 5), with EbpC being the dominant genotype. The human-pathogenic subtypes (ST1, ST3, and ST5) and genotypes (EbpC, CHG23) that were observed in this study indicate a potential threat to public health. Our findings offer basic information for preventing and controlling these zoonotic pathogens in the study area. Additional investigations are necessary to better understand their genetic characteristics and zoonotic potential within Guangxi Province.

Giardia duodenalis (G. duodenalis) is a globally distributed zoonotic protozoan that parasitizes the small intestines of humans and various mammals, such as goats and sheep. The objective of this study was to establish a convenient, accurate, and specific method based on restriction fragment length polymorphism (RFLP) for genotyping assemblages A, B and E of G. duodenalis in goats. The β-giardin gene was amplified using primer pairs bgF1, bgR1, bgF2 and bgR2 by nested PCR. The PCR products were digested with the restriction enzymes Hinf I and Bgl I. The established PCR-RFLP method was used to detect and analyze the genetic subtypes of G. duodenalis in 130 fecal samples from goats and compared simultaneously with microscopic examination and nucleic acid sequencing for G. duodenalis. Genetic sequencing confirmed that the PCR-RFLP method accurately distinguished G. duodenalis assemblages A, B and E, as well as different combinations of mixed infections of these three assemblages. Among the 130 samples tested by PCR-RFLP, a total of 26 samples (20.00

Giardia duodenalis, Cryptosporidium parvum, Blastocystis spp. and Enterocytozoon bieneusi are four common zoonotic parasites associated with severe diarrhea and enteric diseases. In this study, we developed a multiplex PCR assay for the simultaneous detection of these four zoonotic protozoans in goat stool samples and assessed its detection efficiency. Specific primers were designed from conserved gene sequences retrieved from GenBank, and the PCR conditions were optimized. Genomic DNA from 130 samples was subjected to both single-target PCR and multiplex PCR. The multiplex PCR assay successfully amplified specific gene fragments (G. duodenalis, 1400 bp; C. parvum, 755 bp; Blastocystis spp., 573 bp; E. bieneusi, 314 bp). The assay sensitivity was ≥102 copies of pathogenic DNA clones with high specificity confirmed by negative results for other intestinal parasites. The detection rates were 23.08% (30/130) for G. duodenalis, 24.62% (32/130) for C. parvum, 41.54% (54/130) for Blastocystis spp., and 12.31% (16/130) for E. bieneusi, matching the single-target PCR results. The sensitivity and predictive values were 100.00%. This multiplex PCR provided a rapid, sensitive, specific, and cost-effective approach for detecting these four parasites. It also provided essential technical support for the rapid detection and epidemiological investigation of G. duodenalis, C. parvum, Blastocystis spp., and E. bieneusi infections in goat fecal samples.

Schistosomiasis, caused by Schistosoma japonicum, continues to pose a major public health threat in East Asia, with an estimated 71 million people at risk of infection. Domestic animals, especially buffaloes and goats, serve as important reservoir hosts, facilitating the transmission of the parasite to humans. While praziquantel (PZQ) is the first-line treatment for schistosomiasis due to its broad-spectrum efficacy against adult schistosomes, its prophylactic potential is less explored. This study aimed to evaluate the efficacy of PZQ in preventing S. japonicum infection in buffaloes and goats via assessing worm burden, worm size, hematological changes, and immune modulation. In the present study, buffaloes and goats were pretreated with PZQ at various doses (7–25 mg/kg body weight), followed by infection with S. japonicum cercariae. The results showed significant reductions in total worm burden and female worm burden, with one oral administration at 13 mg/kg for buffaloes and one injection at 25 mg/kg for goats offering the most robust protection. Worm length was also significantly reduced in both buffaloes and goats, indicating that PZQ not only prevented infection in this study but also inhibited worm growth. Furthermore, PZQ pretreatment modulated immune responses, as evidenced by increased levels of nitric oxide (NO) and interleukin-2 (IL-2) in buffaloes and Lym% in goats. These findings suggest that PZQ has significant prophylactic potential in livestock, offering a practical solution for reducing schistosome transmission from animals to humans in endemic regions. Additionally, this study indicates that PZQ pretreatment does not contribute to resistance development, as newly established infections are effectively cleared during the initial treatment window.

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.

COPYRIGHT © 2023 Hong, Kassegne, Okpeku, Zheng and Chen. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Editorial: Control and prevention of tropical diseases by advanced tools and the One Health approach

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.

Blastocystis spp., Enterocytozoon bieneusi, and Giardia duodenalis are three common zoonotic intestinal parasites that cause severe diarrhea and enteric diseases. Leizhou black goats are characterized by a high reproductive rate, fast growth, and good meat quality, making them one of the pre-eminent goat breeds in China. Goats are reportedly common reservoirs of these three intestinal pathogens, but no information on their prevalence or genotypic distributions in black goats in Guangdong Province, China, is available. A total of 226 fecal samples were collected from goats in Zhanjiang city and genomic DNA was extracted from them. The presence of the three pathogens was detected using nested PCR targeting the sequences encoding SSU rRNA (Blastocystis spp.), the internal transcribed spacer of rRNA (ITS; E. bieneusi), as well as beta-giardin, glutamate dehydrogenase, and triosephosphate isomerase (G. duodenalis). All PCR products were sequenced to determine the species and genotypes of the organisms. The total prevalence rates of Blastocystis spp., E. bieneusi, and G. duodenalis were 33.63% (76/226), 17.70% (40/226), and 24.78% (56/226), respectively. Four subtypes of Blastocystis spp. were detected: ST5 (n = 6), ST10 (n = 50), ST14 (n = 14), and ST21 (n = 6). Among them, ST10 was the dominant genotype, accounting for 65.79% of strains, followed by the genotypes ST14 (18.42%), zoonotic ST5 (7.89%), and ST21 (7.89%). Four genotypes of E. bieneusi were detected: CHG3 (n = 32), CM21 (n = 4), CHG1 (n = 2), and ET-L2 (n = 2). Among these, CHG3 was the dominant genotype. Assemblage E (n = 54) and concurrent assemblages A and E (n = 2) were identified in the G. duodenalis-positive goats using multilocus genotyping. Blastocystis spp., E. bieneusi, and G. duodenalis infections were common in Leizhou black goats, all of which have zoonotic genotypes, indicating the potential risk of zoonotic transmission. Our results provide basic data for the prevention and control of these three intestinal pathogens. Further studies are required to better understand their genetic characteristics and zoonotic potential in Guangdong Province.

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.

Insects and bacteria, two of the most widespread groups of organisms on earth, establish diverse symbiotic associations from strict parasitism to obligate mutualism. Mutualistic relationships can be instrumental for insects to adapt and survive, and insects are expected to have evolved ways of facilitating the colonization and proliferation of the symbi-otic bacteria. Pederin-producing endosymbionts (PPE) in the rove beetle Paederus fuscipes produce the toxic substance pederin, which provides the beetle with a defense against insect and arachnid predators. Most previous studies on this mutualism have focused on the bacteria, but the molecular basis for its interactions with the beetle host are not known. Here we sequenced and annotated the genome of P. fuscipes, representing the first complete genome sequence of a member of the beetle family Staphylinidae; we found expansions of P450 and GST gene families potentially contributing to the wide distribution of P. fuscipes. By assessing the microbiota of P. fuscipes and FISH visualization, we showed that PPE were the dominant bacterial phylotype in females and were common in female reproductive organs. In addition, we found that immune genes up-regulated in reproductive tissues were hostile to Gram-positive bacteria, but likely provided a favorable environment for the colonization and proliferation of Gram-negative PPE bacteria in female reproductive tissues. This work combining multi-omics with FISH analyses thereby helps to unravel this mutualistic interaction and other mutualistic insect-endosymbiont systems.

布鲁菌主要免疫相关抗原有脂多糖、外膜蛋白、菌体蛋白,研究这类抗原是解决目前布病菌疫苗存在保护时间短以及布病血清学诊断无法区分免疫、感染以及毒力返强的重要突破口.生物技术的发展促进了对抗原的结构、抗原表位及其诱导的免疫应答等方面的深入研究,并在此基础上构建了多种重组融合蛋白疫苗、DNA疫苗、亚单位疫苗、包含优势表位的多价疫苗;同时免疫相关抗原的研究也为布病诊断试剂的开发奠定了基础并提供了更多选择.