ABSCICS: Applied Bacterial Spore Control in Industrial and Clinical Settings

细菌内孢子是地球上抵抗能力最强的生命形式之一，它允许细菌在极端的温度、干燥、消毒剂、辐射和厌氧条件下存活。人类的寿命是惊人的，不是用几十年或几百年来衡量的，而是以百万年来衡量的。这些显着的结构是梭状芽胞杆菌属细菌最重要的特征，并为其致病成员的传播奠定了基础。然而，绝大多数梭状芽胞杆菌是完全良性的，可以可持续地用于生产社会所需的化学品和燃料。梭状芽胞杆菌也是有价值的治疗药物(如肉毒杆菌和夏福乐)的来源。然而，它们潜在的最重要的用途之一在于它们作为治疗实体肿瘤的载体的潜力，以及通过利用它们的内孢子来传递微生物群的潜力。内孢子是一种理想的药物。易于制备和提纯，一旦制成，非常适合长期储存。它们很容易给药(静脉或口服)，一旦给药，依赖于一个自然过程(萌发)被激活-转化为营养细胞。然而，使它们成为理想的输送载体的特性也损害了它们感知的安全性，因为氧气敏感的营养细胞原位转化为内孢子(孢子形成)导致了一种高度抗性的试剂，可以分散到外部环境中并在其中存活。为了应对这种风险，SBRC创造了一种梭状芽胞杆菌菌株，它只在规定的条件下产生孢子--一种有条件的产孢子(Spoc)菌株。这允许在实验室条件下产生高孢子滴度，但一旦在目标利基(肿瘤或微生物群)中萌发，梭状芽胞杆菌仍然是营养细胞，不能再次产孢。这种复杂的残疾形式将确保避免梭状芽胞杆菌的传播，从而满足监管机构的关切。除了在治疗输送中的用途外，Spoc菌株对基于芽胞形成细菌的商业过程也有价值。这是因为工业内部不愿使用产生孢子的细菌，因为它们很难从生产设施中移除。虽然零突变体阻止了孢子的产生，但对于氧气敏感的厌氧菌来说，由于营养细胞会因暴露在空气中而迅速死亡，因此储存和维护种子菌株是有问题的。Spoc菌株允许通过在诱导剂存在的情况下生长来储存和维持处于孢子状态的菌株。随后在没有诱导剂的情况下进行大规模培养，将防止生产设施中的孢子污染。我们的理念是设计、建造和测试特定于已确定的商业应用的条件产孢梭菌(Spoc)菌株。控制细菌孢子形成的能力有许多这样的用途，特别是与厌氧菌有关的用途。这些涉及针对特定生态位疾病和紊乱的治疗载体，作为防止工艺设施的孢子污染和限制细菌向环境传播的一种手段，在某些应用中，还可控制诱导产孢量。

The bacterial endospore is one of the most highly resistant life-forms on earth and allows the bacterium to survive exposure to extremes of temperature, desiccation, disinfectants, radiation, and, in the case of anaerobes, oxygen. The longevity of survival is astounding and can be measured not in tens or hundreds of years but, in millions. These remarkable structures are the single most important feature of the bacterial genus Clostridium and underpin the spread of its disease-causing members. The vast majority of Clostridia are, however, entirely benign, and may be used sustainably to produce the chemicals and fuels society needs. Clostridia are also a source of valuable therapeutics (e.g., BoTox and Xiaflex). One of their potentially most significant uses, however, resides in their potential as therapeutic delivery vehicles for solid tumours and the microbiome through exploitation of their endospores. Endospores are an ideal pharmaceutical. Easy to prepare and purify, once made they are admirably suited to long term storage. They are simple to administer (intravenously or orally) and once delivered rely on a natural process (germination) to be activated - conversion to vegetative cells. However, the properties that make them ideal delivery vehicles also compromise their perceived safety, as the in situ conversion of an oxygen sensitive vegetative cell to an endospore (sporulation) leads to a highly resistant agent that can be dispersed to, and survive in, the external environment. To counter this risk, the SBRC has created a clostridial strain which only produces spores under defined conditions - a conditionally sporulating (Spoc) strain. This allows the generation of high spore titres under laboratory conditions, but once germinated in the target niche (tumour or microbiome) the Clostridia remain as vegetative cells and are unable to sporulate again. Such a sophisticated form of disablement will ensure that dissemination of Clostridia is avoided, thereby satisfying the concerns of regulatory agencies. Over and above their use in therapeutic delivery, Spoc strains are of value to commercial processes based on spore forming bacteria. This is because there is reluctance within industry to use bacteria that make spores as they are very difficult to remove from production facilities. While null mutants prevent spore production, in the case of an oxygen-sensitive anaerobe, it makes it problematic to store and maintain seed strains as vegetative cells are rapidly killed by exposure to air. A Spoc strain allows the storage and maintenance of strains in the spore state through growth in the presence of the inducers. Subsequent large-scale cultivation in the absence of inducers will prevent spore contamination of manufacturing facilities. Our concept is to design, build and test conditionally sporulating (Spoc) strains of Clostridia specific to identified commercial applications. The ability to control bacterial sporulation has a multitude of such uses, particularly in relation to anaerobes. These relate to therapeutic delivery vehicles for niche-specific diseases and disorders, as a means of both preventing spore contamination of process facilities and limiting the dissemination of the bacterium to the environment and, in some applications, the controlled induction of sporulation.