Giardia duodenalis is a globally distributed zoonotic parasite primarily transmitted through the fecal-oral route, infecting various vertebrates, and the infection of which is prevalent in goats. Immune cells play a crucial role in pathogens invasion, and neutrophil extracellular traps (NETs) released by neutrophils serve as a non-specific defense mechanism against pathogens including parasites. In this study, we investigated the characteristics, components, and molecular mechanisms of goat NETs upon stimulation with G. duodenalis trophozoites. This study demonstrates that G. duodenalis trigger dose-dependent NETs formation in goat neutrophils, composed of DNA, citrullinated histone H3 (CitH3), and neutrophil elastase (NE). Reactive oxygen species (ROS) accumulation synchronizes with NETosis during G. duodenalis infection. Inhibitor experiments confirmed that G. duodenalis-induced NETs and ROS production depend on TLR2/4 signaling and require NADPH oxidase (NOX), ERK1/2, and p38 MAPK activation. This work identifies TLR2/4, NOX, ERK1/2, and p38 MAPK pathways as key regulators of NETs/ROS coordination during G. duodenalis infection, providing the first evidence of G. duodenalis-triggered NETs in goats. The findings highlight NETs as critical components of anti-G. duodenalis immunity and suggest potential for NETs-targeted therapeutic strategies.

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.

Neospora caninum (N. caninum) is a protozoan parasite that poses a serious risk to livestock by infecting various domestic and wild animals. Loop-Mediated Isothermal Amplification (LAMP) offers a cost-effective, highly sensitive, and specific method for detecting protozoan parasites. This study aims to develop a precise, rapid, and visually assessable colorimetric LAMP method, improving on traditional techniques. We employed a rigorous screening process to identify the optimal primer set for this experiment. Subsequently, we fine-tuned the LAMP reaction at 65 degrees C for 40 min with 270 mu mol/L neutral red. We then confirmed the specificity of primers for N. caninum through experimental validation. The LAMP method demonstrated a lower detection limit compared to traditional Polymerase Chain Reaction (PCR) techniques. While LAMP offers clear advantages, the prevalence of DNA detected in 89 sheep serum and 59 bovine serum samples using the nested PCR method was 3.37 % (3/89) and 1.69 % (1/59), respectively. In contrast, when the LAMP method was employed, the prevalence of detected DNA rose to 5.61 % (5/89) for sheep and 3.38 % (2 /59) for bovine. A comparison of two molecular assays using the intragroup correlation coefficient (ICC) resulted in a value of 0.999 (95 % CI: 0.993-0.996, p < 0.001), indicating the LAMP method is in the "better" range according to James Lee's categorization. The LAMP technique, optimized with specific primers of N. caninum and neutral red dye, not only exhibited higher sensitivity but also provided convenience over conventional PCR methods, highlighting its potential for on-site applications and cost-effective field detection.

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.

Introduction:Porcine reproductive and respiratory syndrome virus (PRRSV) is the causative agent 13 of porcine reproductive and respiratory syndrome (PRRS), which is one of the most economically 14 devastating viruses in the Vietnamese swine industry. Methods:With a view toward determining the 15 genetic variation among PRRSV strains in Vietnam, we examined 271 PRRSV GP5 protein 16 sequences obtained from strains isolated in Vietnam from 2007 to 2023, for which we constructed 17 phylogenetic trees. Additionally, a collection of 52 PRRSV-1 strains and 80 PRRSV-2 strains 18 isolated in different years were specifically selected for nucleotide and amino acid homology analysis 19 and amino acid sequence alignment. Results:The results revealed 76.1%-100.0% nucleotide and 20 75.2%-100.0% amino acid homologies for the PRRSV-1 GP5 gene, and 81.8%-100.0% nucleotide 21 and 81.1%-100.0% amino acid homologies for the PRRSV-2 GP5 gene. Amino acid mutation sites 22 in PRRSV-2 were found to be primarily distributed in the signal peptide region, antigenic sites, two 23 T-cell antigen regions, two highly variable regions (HVRs), and in the vicinity of the neutralizing 24 epitope, with a deletion mutation occurring in the neutralizing epitope, whereas amino acid mutations 25 in the PRRSV-1 sequences were found to occur predominantly in two T-cell epitopes. Genetic 26 analysis revealed that PRRSV-1 strains in Vietnam are of subtype 1 (Global), whereas PRRSV-2 27 strains are categorized into sublineages L1A, L5A, and L8E, with L8E being the predominantly 28 prevalent strain at present. Recombination analyses indicated that no significant recombination 29 events have occurred in any of the assessed 271 Vietnamese PRRSV strains. Discussion:Our 30 analyses of 271 Vietnamese PRRSV strains have yielded valuable insights regarding the 31 epidemiological trends and genetic dynamics of PRRSV in Vietnam, and will provide a theoretical 32 basis for formulating prevention and control measures for PRRS and the development of PRRS 33 vaccines.

为了建立一种特异性强、灵敏度高、重复性好的NADC34-likePRRSV[我国近年来猪繁殖与呼吸综合征病毒(porcine reproductive and respiratory syndrome virus,PRRSV)主要流行株之一]快速检测方法,针对 NADC34-like PRRSV的保守基因ORF5设计并合成特异性引物(F/R)和探针(P),筛选最佳引物、探针浓度组合,建立NADC34-like PRRSV实时荧光定量逆转录聚合酶链反应(reverse transcription PCR,RT-PCR)检测方法,并对该方法进行方法学分析和临床阳性样品检测验证.结果表明:该方法反应体系中,引物(F/R)和探针(P)的最佳工作浓度分别为0.4 μmol/L和0.2 μmol/L;该方法荧光定量RT-PCR曲线在1.56× 101～1.56× 1010拷贝/μL范围内呈现良好线性关系,灵敏度可达1.56×101拷贝/μL[高于常规RT-PCR(1.56×103拷贝/μL)],批内和批间重复实验变异系数均小于0.50％;采用新建立的荧光定量RT-PCR方法检测132份NADC34-like PRRSV阳性样品,均获得荧光信号曲线.实验结果说明:所建立的NADC34-like PRRSV荧光定量RT-PCR检测方法特异性强、灵敏度高、重复性好,可用于临床样品NADC34-like PRRSV检测.

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.

Simple Summary NSP11 is a non-structural protein of the porcine reproductive and respiratory syndrome virus (PRRSV) that influences viral replication and interacts with the host's innate immune response. We reviewed the genetic evolution of NSP11, its effects on PRRSV replication and virulence, its interactions with other PRRSV and host proteins, the regulation of host immunity, the conserved characteristics of nidovirus-specific endonuclease (NendoU), and its diagnosis, providing an important theoretical basis for in-depth studies on PRRSV pathogenesis and vaccine design.Abstract Porcine reproductive and respiratory syndrome (PRRS) is a virulent infectious disease caused by the PRRS virus (PRRSV). The non-structural protein 11 (NSP11) of PRRSV is a nidovirus-specific endonuclease (NendoU), which displays uridine specificity and catalytic functions conserved throughout the entire NendoU family and exerts a wide range of biological effects. This review discusses the genetic evolution of NSP11, its effects on PRRSV replication and virulence, its interaction with other PRRSV and host proteins, its regulation of host immunity, the conserved characteristics of its enzyme activity (NendoU), and its diagnosis, providing an essential theoretical basis for in-depth studies of PRRSV pathogenesis and vaccine design.

为探索十二指肠贾第虫(Giardia duodenalis)谷氨酸脱氢酶(glutamate dehydrogenase,GDH)在滋养体中的分布和酶动力学等生物学特性,对GDH进行了克隆并构建原核表达质粒pET-28a-GDH,然后转化至BL21(DE3)plysS感受态细胞中经IPTG诱导表达,对表达产物进行SDS-PAGE和Western blot分析,以Ni2+亲和层析纯化.对纯化的重组GDH进行体外酶动力学分析并免疫小鼠制备多克隆抗体,最后用间接免疫荧光技术对滋养体中的GDH进行定位.结果显示,贾第虫GDH的编码序列长1350 bp,试验成功构建pET-28a-GDH重组表达质粒并诱导表达,重组蛋白约为49.7 ku,且大部分以可溶性形式存在.ELISA和Western blot结果表明,贾第虫GDH具有良好免疫原性,获得的多克隆抗体具有较强特异性.间接免疫荧光定位显示GDH主要位于滋养体的胞质中.酶动力学研究结果显示,GDH最适反应pH约为9.3、最适温度约为42℃,对L-谷氨酸和NADP+的Km值分别为4.485 mmol/L±0.5062 mmol/L和119.5μmol/L±10.1μmol/L.研究结果为深入研究贾第虫GDH的生物学功能奠定了基础.

为掌握在饲料禁抗和养殖端限抗背景下规模化猪场胞内劳森菌的流行情况,为猪增生性肠炎的精准防控提供依据.该研究运用巢式PCR和间接ELISA方法对饲料禁抗后不同来源的粪便样品和血清样品进行检测.饲料禁抗背景下,对采自不同猪场695 份粪样的巢式PCR检测显示,猪群胞内劳森菌的总体感染率为23.88％,保育猪、肥育猪和种猪感染率分别为16.56％、29.58％和24.63％.对饲料禁抗和饲养期间限抗猪群的跟踪调查结果为,保育猪在30、44、58、72日龄的感染率分别是16.67％、20.00％、50.00％和70.00％;后备母猪的感染率44.44％—66.67％.对338份不同猪场送检血清样品的ELISA检测显示,胞内劳森菌的抗体阳性率为42.6％,不同猪场的阳性率10％—75.90％.上述结果表明,现阶段我国规模化猪场胞内劳森菌PCR检测阳性率和ELISA检测的阳性率均处于较高水平.饲料禁抗以及饲养期间限抗的保育猪和后备母猪群跟踪调查的最高感染率分别达70％和66.67％,保育猪随着饲养日龄的增加感染率呈明显地升高趋势.因此,在饲料禁抗背景下,规模化猪场应更加重视猪增生性肠炎的防控.

Giardia duodenalis（G.duodenalis）is a common zoonotic protozoan parasite that infects the small intestines of humans,livestock,dogs,cats and other mammals.Giardiasis which caused by G.duodenalis has been noted as one of the neglected diseases endangering human health by the World Health Organization.The intestinal protozoan parasite Giardia has a simple life cycle consisting of disease causing trophozoites and infectious cysts.Giardia trophozoites differentiate into infectious cysts in response to hostile environment（either low cholesterol conditions or alkaline pH and high bile conditions）.Encystment is crucial for Giardia’s survival,transmission and pathogenesis.Giardiasis is often caused by the host ingestion of infectious cystscontaminated food and water.The cyst wall is an important shield for Giardia cysts to resist adverse external environment,maintain their viability and infective activity.About 40% of the encapsulated wall is composed of proteins and the rest is carbohydrates such as Nacetylgalactosamine and lipids.It is shown that the cyst wall of Giardia mainly contains three cyst wall proteins（CWP1,CWP2and CWP3）.Cyst wall proteins not only play an important role in maintaining the viability of the cyst,but also has important value in the diagnosis of giardiosis and the development of oral vaccine.This review mainly introduced the composition and formation of Giardiacyst wall,the induction and regulation of encystation,and the research advances on cyst wall proteins in disease diagnosis and vaccines development,in order to provide reference for the follow-up related research.

为调查广东省部分地区奶牛贾第虫的流行现状和分子特征,评估其人兽共患风险,从广东省3个地市采集366份奶牛粪便样本,基于贾第虫谷氨酸脱氢酶(gdh)和β-贾第素(bg)基因进行套式PCR,将测序所得序列进行Blast比对以确定基因型,运用Mega7.0软件的最大似然法构建进化树.结果共检出69份阳性样本,阳性率为18.85％.肇庆、广州和梅州奶牛群的阳性率分别为45.71％、16.27％和3.45％,不同地区差异显著(P＜0.05).育成牛感染率(25.96％)显著高于犊牛感染率(15％).系统进化分析显示69份阳性样品中有11份为A1亚集聚体,29份属A1和E混合感染,29份为集聚体E的不同亚型.结果表明,广东省奶牛贾第虫感染率略高于国内大多数已知地区,不同地区和不同生长阶段的牛群感染率差异显著,广州市奶牛以A1为优势亚集聚体,应重视其可能引起的公共卫生问题.

Aflatoxin B1 (AFB1) is a mycotoxin with strong toxicity and play a large proportion in aspergillosis. Heterophil extracellular traps (HETs) was considered as an innate immune response of chickens to resist pathogens. AFB1 has been reported to trigger macrophages extracellular traps (METs) in THP-1 cells and RAW264.7 cells, but whether AFB1 could also activate HETs release, and the mechanism underlying AFB1-activated HETs in chicken remains unclear. In this study, we confirmed that AFB1could induce HETs release, which was a network of DNA-based structures consist of citrullinated histone 3 (citH3) and elastase. Meanwhile, AFB1-activated HETs rely on the glycolytic process to provide energy, NADPH oxidase and p38 signaling pathway. Moreover, it has been verified that AFB1-activated HETs release could significantly increase the biochemical indexes of liver (ALT and AST) and kidney (CRE and BUN) in serum. In addition, histopathological observation showed that AFB1 caused swelling, necrosis and vacuolation of hepatocytes in liver, and necrosis, exfoliated of nephrocyte in kidney. Further investigation demonstrated that AFB1 significantly decreased the levels of SOD and GSH-PX but increased the level of MDA, and meanwhile induced the mRNA expressions of TNF-α, IL-6 and IL-1β, iNOS, COX-2, NLRP3, caspase-1, caspase-3 and caspase-11. However, all these AFB1-induced biochemical indexes and histopathological changes were effectively alleviated by DNase I (the standard degradant for HETs). In conclusion, it has preliminary confirmed that AFB1-activated HETs formation contributed to the immunotoxicity in chicken and provide new strategies for the therapy in aspergillosis.

[目的]了解广东省不同地区猪源十二指肠贾第虫(Giardia duodenalis,简称贾第虫)的流行现状和分子特征,并评估其人兽共患风险.[方法]从广东省10个地区采集新鲜猪粪样品,采用显微镜镜检,并应用巢式PCR对贾第虫谷氨酸脱氢酶(glutamate dehydrogenase,gdh)基因进行扩增,根据扩增结果计算不同地区和生长阶段猪贾第虫的阳性率.对所有的PCR阳性产物进行测序,将获得的贾第虫gdh基因序列进行BLAST比对,确定贾第虫的基因型;运用Mega 7.0软件的最大似然法构建进化树.[结果]贾第虫包囊呈椭圆形,囊壁较厚,大小为(10～14)μm×(7～10)μm,具有明显纵向轴柱,细胞核分布于轴柱两侧.521份受检样品中共检测出94份PCR阳性样品,阳性率为18.04％(94/521),其中茂名和清远的阳性率较高,分别达40.00％(10/25)和35.06％(27/77);肇庆和韶关的阳性率较低,分别为3.90％(3/77)和8.57％(3/35);佛山、江门、阳江、河源、广州和惠州的阳性率分别为11.11％(2/18)、15.31％(15/98)、11.43％(4/35)、13.33％(4/30)、9.38％(3/32)和24.47％(23/94).不同饲养阶段的猪群的阳性率调查发现,母猪的贾第虫阳性率(24.55％)显著高于断奶仔猪(13.30％)(P＜0.05),与育肥猪的贾第虫阳性率(19.23％)差异不显著(P＞0.05).基于gdh基因序列的基因分型和系统进化分析共发现5种贾第虫亚集聚体,即集聚体A Ⅰ和集聚体E的4种不同亚型,包括集聚体E1、E2、E10和E13,其中61.70％(58/94)测序阳性样品属于集聚体AⅠ,38.30％(36/94)属于集聚体E的不同亚型.[结论]广东猪源贾第虫的感染较普遍,不同地区和不同生长阶段的猪感染率存在一定差异.其中,人兽共患性集聚体A Ⅰ为优势亚集聚体,表明广东省猪源贾第虫存在人兽跨物种传播的风险,应重视该病可能引起的公共卫生问题.

课程思政是加强大学生思想政治教育、促进学生全面发展的重要途径.为实现思政课程和课程思政有机结合,作者对"兽医寄生虫学"授课进行了实践和思考.结合课程特点,阐述课程思政的意义及目标,探索课程思政在"兽医寄生虫学"教育中的实施路径,挖掘课程所蕴含的思政元素,创新教育教学方法并总结实践经验,以期达到德育并行、立德树人的教学目的,培养德才兼备、高素质的动物医学专业人才.

随着慕课广泛在各高校建设后,慕课的有效使用成为重点,尤其是希望学生能够自主自觉地进行慕课学习,实现以学生学习为中心的教学是教师追求的目标.由此,本文结合自己《养犬与养猫学》慕课的使用以及学生学习为主体的教学设计实际,探讨如何利用慕课充分实现学生学习为中心的教学方法或教学设计,从而为教学改革提供有价值的参考资料.

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.

BACKGROUND:Yellow cattle and water buffalo are important natural reservoir hosts and the main transmission sources of Schistosoma japonicum in endemic areas of China. The worms from the two hosts have marked differences in general worm morphology and ultrastructure, gene transcription and protein expression profiles.RESULTS:To investigate microRNAs (miRNAs) involved in the regulation of schistosome development and survival, we compared miRNA expression profiles of adult schistosomes derived from yellow cattle and water buffalo by using high-throughput sequencing with Illumina Hiseq Xten. Schistosoma japonicum from water buffalo and yellow cattle yielded 63.78 million and 63.21 million reads, respectively, of which nearly 50% and 49% could be mapped to selected miRNAs in miRbase. A total of 206 miRNAs were identified, namely 79 previously annotated miRNAs of S. japonicum and 127 miRNAs that matched with the S. japonicum genome and were highly similar to the annotated miRNAs from other organisms. Among the 79 miRNAs, five (sja-miR-124-3p, sja-miR-219-5p, sja-miR-2e-3p, sja-miR-7-3p and sja-miR-3490) were significantly upregulated in the schistosomes from water buffalo compared with those from yellow cattle. A total of 268 potential target genes were predicted for these five differentially expressed miRNAs. Eleven differentially expressed targets were confirmed by qRT-PCR among 15 tested targets, one of which was further validated through dual-luciferase reporter assay. Among the 127 'possible' S. japonicum miRNAs, ten were significantly differentially expressed in the schistosomes from these two hosts.CONCLUSIONS:These results highlight the important roles of miRNAs in regulating the development and survival of schistosomes in water buffalo and yellow cattle and facilitate understanding of the miRNA regulatory mechanisms in schistosomes derived from different susceptible hosts.