Development of novel mesoporous silica nanoparticle sensing sprays for rapid field detection of foot-and-mouth disease (FMD)

农业和粮食生产未来必须面对的挑战之一是为不断增长的世界人口进行可持续粮食生产的长期管理。在这方面的一个关键因素是控制疾病和改善动物健康，以此作为安全、高效和高质量生产的基础。疾病对全球畜牧业生产的影响，从而对粮食安全的影响以数十亿GB为单位。全球化和气候变化正在推动新出现和重新出现的动物疾病和人畜共患病的空前增加。因此，通过提供工具以及早发现和控制具有重要经济意义的全球牲畜疾病，改善动物卫生系统是应对这一令人震惊的局势的最有效办法。口蹄疫是由高度传染性的口蹄疫病毒(FMDV)引起的一种具有重要经济意义的家畜疾病。该疾病在全球77%的牲畜种群中传播，造成约50-210亿美元的生产损失和控制措施。按地区划分的总体经济损失最大的是中国，共计20多亿美元，而生产损失造成的直接财务影响最大的是非洲，估计损失为8.15亿美元。口蹄疫流行的国家对英国等无疾病国家构成了巨大威胁，例如2001年的疫情控制成本超过80亿GB。口蹄疫通过生产损失(生产者、市场、屠宰场、食品加工商和消费者)、根除疾病损失(检疫执法、安乐死、身体处理、赔偿、消毒)和贸易损失(限制对无口蹄疫国家的贸易)造成这些巨大的经济损失。常规实验室检测被广泛用于口蹄疫诊断，尽管相对较快，但结果报告的速度受到从农场向实验室发送样本的时间延迟的影响。这些延误对证据的质量有直接影响，这些证据可用于在口蹄疫疑似病例发生时支持立即作出诊断决定。缺乏快速检测结果对绵羊和山羊的口蹄疫疑似病例尤其重要，因为在这些物种中，仅根据临床症状进行诊断可能非常具有挑战性。这些因素推动了可在现场使用的快速测试的发展。事实上，在英国2001年口蹄疫暴发后的主要报告中就建议使用这种快速诊断化验。可以在农场部署以快速检测病毒抗原的简单的笔侧诊断方法已经发展成用于检测口蹄疫病毒的横向流动装置(LFD)的形式，但这些试验的灵敏度低于分子方法。因此，研究的重点是将实时RRT-PCR转移到现场，但由于大多数平台的成本昂贵，并且需要对设备进行去污染，重点已转移到替代分析方法，如环介导的等温扩增(LAMP)。然而，目前LAMP仍然需要昂贵的试剂和设备、多个进样步骤和熟练的操作员来执行和解释测试。因此，通过预防和控制动物疾病来保护动物健康对于可持续的食品生产和兽医公共卫生至关重要。该项目将开发和验证第一种“诊断性口蹄疫病毒传感喷雾”，我们预计这种喷雾可以非侵入性地应用于怀疑显示口蹄疫临床症状的动物的嘴、脚、鼻子和乳头区域。使用一种创新的方法，一种肉眼可以检测到的无毒染料将从纳米颗粒中释放出来，只有当它们与整个口蹄疫病毒或病毒释放的酶接触时才会产生反应。

Among the challenges agriculture and food production has to face in the future, is the long-term management of sustainable food production for the growing world population. A crucial factor in this respect is the control of diseases and improvement of animal health as a basis for safe, efficient, and high-quality production. The impact of disease on global animal production and thus food security are measured in the £billions. Globalisation and climate change are driving the unprecedented increase of emerging and re-emerging animal diseases and zoonotics. Therefore improving animal health systems by providing tools to enable early detection and control of economically important global livestock diseases is the most effective response to this alarming situation. Foot-and-mouth disease (FMD) is a livestock disease of great economic importance, caused by the highly contagious foot-and-mouth disease virus (FMDV). The disease circulates in 77% of the global livestock population, costing ~between $5 -21 billion in production losses and control measures. The greatest overall economic loss by region is China totalling more than 2 billion USD, whereas the direct financial impacts as a result of production losses are greatest in Africa with an estimated loss of $815 million. Countries where FMD is endemic pose a great threat to disease free countries such as the UK for example the 2001 outbreak cost more than £8bn to control. FMD results in these huge economic losses through production losses (producers, markets, slaughterhouses, food processors, and consumers), disease eradication losses (quarantine enforcement, euthanisation, disposal of carcases, compensation, disinfection) and trade losses (restriction of trade to FMD free countries). Routine laboratory tests are widely used for FMD diagnosis and although relatively quick, the speed of result reporting is confounded by the time delays associated with sending samples from the farm to the laboratory. These delays have direct impacts upon the quality of evidence that can be used to support immediate diagnostic decisions in the event of suspect cases of FMD. The lack of a quick test result is particularly important for suspect FMD cases in sheep and goats, since diagnosis based solely on clinical signs can be very challenging in these species. These factors have driven the development of rapid tests which can be used in situ. In fact, the use of such rapid diagnostic assays was recommended in major reports following the UK 2001 FMD outbreak. Simple pen-side diagnostics which can be deployed on farm to rapidly detect viral antigen have been developed in the form of lateral flow devices (LFD's) for detection of FMDV, however the sensitivity of these tests is less than that of molecular methods. Therefore, research was focused on transfering real-time rRT-PCR into the field, but with the cost of most platforms being expensive and the need for decontamination of the equipment, emphasis has shifted to alternative assays such as loop-mediated isothermal amplification (LAMP). However, at present LAMP still requires expensive reagents and equipment, multiple pipetting steps and a skilled operator to perform and interpret the test. Safe-guarding of animal health through prevention and control of animal diseases is therefore of paramount importance for sustainable food production and veterinary public health. This project will see the development and validation of the first 'diagnostic FMDV sensing spray' which we anticipate can be applied non-invasively to the mouth, feet, nasal and teat area of animals suspected of displaying clinical signs of FMDV. Using an innovative approach a non-toxic dye which can be detected by the naked eye will be released from nanoparticles which only respond when they either come into contact with the whole FMDV virus or with enzymes released by the virus.