Mitigating the global impact of fasciolosis: developing diagnostics for triclabendazole resistance in Fasciola species

减轻片形吸虫病的全球影响：开发片形吸虫属三氯苯达唑耐药性的诊断方法

• 批准号: 2887794
• 金额: --
• 依托单位: University of Liverpool
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2887794
• 关键词: Mitigating; global; impact; fasciolosis; developing

Summary:Fasciolosis and one health Fasciola spp infect livestock and, as a zoonotic parasite, this leads to infection in humans. Estimates of infection suggest between 2.4 and 17 million people are infected worldwide, typically in LMIC endemic regions. WHO recognises fasciolosis as a neglected tropical disease. Triclabendazole is the drug of choice for treating infection in livestock as it targets all life cycle stages and it is the only drug licenced for humans. Triclabendazole resistance in Fasciola species was initially reported in livestock species due to intensive treatment regimes, inevitably this led to infection of humans with triclabendazole resistant parasites and failure to effectively treat infections. The ability to detect drug resistant parasites in livestock and humans is key to effective control; better control in livestock reduces the risk of transmission to humans and if humans get infected, testing for resistance can inform on the off-licence use of alternative therapeutics. We need a molecular diagnostic for triclabendazole resistance in Fasciola spp that can be used on both livestock and humans in LMIC settings.Project aims and objectivesFasciolosis is caused by two parasites, Fasciola hepatica and F. gigantica. Fasciola spp have a complex demography, they are either present as species-specific infections (e.g Fasciola hepatica in Peru) or as hybrid forms in regions where their distributions overlap (e.g in India and Pakistan) and introgression of genetic loci between the species has been reported. We have made substantial inroads into identifying a genomic locus that confers triclabendazole resistance in F. hepatica and have localised it to a cluster of seven genes; amongst which are two candidate genes, an ADP ribosylation factor (ARF) and ABC genes (ABCB1), both of which have non-synonymous SNPs that are under selection by triclabendazole. In livestock detection of infection is by coproantigen/presence of eggs in faeces or by antibody detection in serum. Similarly, human faecal samples can be used to detect eggs or Fasciola spp DNA. This project aims to build on our existing understanding of triclabendazole resistance in livestock to mitigate its impact on human health. We will: 1. Conduct whole genome re-sequencing from multiple isolates from both livestock and humans from countries representing different demographics (Peru, India, Pakistan, Cameroon and Senegal)2. Carry out comparative genomics to localise genetic exchange within F. gigantica, F. hepatica and hybrids/introgressed species, with a particular focus on triclabendazole-resistance genes.3. Determine if triclabendazole selection is placed on SNPs within ARF and ABCB1 genes in multiple F. hepatica and F. gigantica isolates of known resistance status from both livestock and humans. 4. Optimise diagnostic molecular methods for species-specific detection of Fasciola spp in faecal samples and duodenal/bile aspirates in humans, in collaboration with clinicians in India and Peru.5. Establish proof-of-principal methodology for molecular diagnostic detection e.g Lec-lamp, to detect SNPs in triclabendazole resistance genes in F. hepatica and F. gigantica isolates for point-of-care use in LMIC settings.The goal of this project is to generate novel genomic sequence data, mapping this to current reference genomes and interrogate gene annotations from multiple liver fluke isolates in order to determine whether resistance genes are conserved across the different species and hybrid forms of Fasciola. Candidate gene sequence variation between known drug resistant and susceptible isolates will be interrogated in order to identify gene changes linked to resistance (resistance markers). Finally, a bespoke molecular diagnostic tool will be developed to detect these resistance markers in samples from livestock and humans. The project aims to combine discovery science with applied diagnostics to positively impact on livestock and human heal

摘要：片形吸虫病和一种健康片形吸虫属感染牲畜，作为一种人畜共患寄生虫，这导致人类感染。感染估计数表明，全世界有240万至1 700万人感染，通常在LMIC流行地区。世卫组织承认肝片吸虫病是一种被忽视的热带疾病。三氯苯达唑是治疗牲畜感染的首选药物，因为它针对所有生命周期阶段，并且是唯一获得许可用于人类的药物。片形吸虫属中的三氯苯达唑耐药性最初是在家畜种属中报告的，这是由于强化治疗方案，这不可避免地导致人类感染三氯苯达唑耐药性寄生虫，并且未能有效治疗感染。检测牲畜和人类中耐药寄生虫的能力是有效控制的关键;牲畜中更好的控制降低了传播给人类的风险，如果人类受到感染，耐药性检测可以为非许可使用替代疗法提供信息。我们需要一种分子诊断方法来检测片形吸虫对三氯苯达唑的耐药性，这种方法可以在LMIC环境中用于家畜和人类。南极洲片形吸虫属具有复杂的人口统计学，它们或者作为种特异性感染（例如秘鲁的肝片形吸虫）存在，或者作为它们分布重叠的地区的杂交形式存在（例如在印度和巴基斯坦），并且已经报道了种之间遗传基因座的渐渗。我们已经取得了实质性的进展，以确定一个基因组位点，赋予三氯苯达唑耐药性的F。Hepatica的基因组，并已将其定位到一个7个基因的簇中;其中有两个候选基因，ADP核糖基化因子（ARF）和ABC基因（ABCB 1），这两个基因都具有在三氯苯达唑选择下的非同义SNP。在家畜中，通过粪抗原/粪便中是否存在虫卵或通过血清中的抗体检测来检测感染。类似地，人类粪便样本可用于检测卵或片形吸虫属DNA。该项目旨在建立在我们现有的了解三氯苯达唑耐药性的牲畜，以减轻其对人类健康的影响。我们将：1.对来自代表不同人口统计学特征的国家（秘鲁、印度、巴基斯坦、喀麦隆和塞内加尔）的牲畜和人类的多个分离株进行全基因组重新测序2。开展比较基因组学研究，定位F. Aristotica，F. hepatica和杂交种/渐渗种，特别关注三氯苯达唑抗性基因。确定是否在多个F中将三氯苯达唑选择置于ARF和ABCB 1基因内的SNP上。hepatica和F.来自家畜和人类的已知耐药状态的嗜热链球菌分离株。4.与印度和秘鲁的临床医生合作，优化用于人类粪便样本和十二指肠/胆汁抽吸物中片形吸虫属物种特异性检测的诊断分子方法。建立分子诊断检测的原理性验证方法，如Lec-lamp，用于检测耐三氯苯达唑的单核苷酸多态性。hepatica和F.该项目的目标是产生新的基因组序列数据，将其映射到当前的参考基因组，并询问来自多个肝吸虫分离株的基因注释，以确定耐药基因是否在片形吸虫的不同物种和杂交形式中保守。将询问已知耐药和敏感分离株之间的候选基因序列变异，以确定与耐药相关的基因变化（耐药标志物）。最后，将开发一种定制的分子诊断工具，以检测牲畜和人类样本中的这些抗性标记。该项目旨在将联合收割机发现科学与应用诊断相结合，对牲畜和人类健康产生积极影响。