The impact of a horizontally acquired genetic material on the transcriptional landscape and phenotypic behaviour of Bacillus cereus as a model to unde

蜡样芽孢杆菌菌株由于其广泛的无脊椎动物关联而在环境中普遍存在。相反，B。炭疽病比较罕见，因为它在遗传上被“锁定”在哺乳动物特有的致病生命周期中。我们正在调查B。蜡状芽孢杆菌菌株G9241（BcG9241），其表现出通常与B相关的表型。蜡状芽孢杆菌在环境温度下，但能够导致炭疽样疾病的人。因此，令人担忧的是，BcG 9241等菌株可能在环境中流行，其作用与它们的B非常相似。cereus祖先，直到它们进入哺乳动物宿主，然后它们可以引起炭疽样疾病。我们的初步工作已经证实，这种致病潜力的转换是由温度决定的，暴露在37摄氏度抑制了许多B。蜡样表型，导致B。炭疽病状态。我们已经表明，这种调控开关在转录后水平上通过一种未知的机制起作用。我们认为，重要的是要了解这种机制如何容易地演变，估计目前的患病率和预测未来的可能性，其他BcG9241样菌株成为一个威胁。事实上，越来越多的报道称，来自世界各地的类似菌株分离株，包括B。蜡状炭疽菌菌株。此外，我们认为，目前推动工业规模养殖的昆虫作为“食品或饲料”有潜在的风险，创造无意的“炭疽工厂”，如果一个BcG9241样的交叉菌株获得访问居民昆虫种群。因此，重要的是要更好地了解这些菌株如何实现这种致病性转换。

Bacillus cereus strains are ubiquitous in the environment by virtue of their widespread invertebrate associations. Conversely B. anthracis is comparatively rare as it is genetically "locked" into an exclusively mammalian pathogenic life cycle. We are investigating the B. cereus strain G9241 (BcG9241), which exhibits phenotypes normally associated with B. cereus at ambient temperatures, yet is capable of causing an anthrax-like illness in people. Therefore, the concern is that strains such as BcG9241 may have the potential to be prevalent in the environment, acting much like their B. cereus ancestors, until they enter a mammalian host, whereupon they can cause anthrax-like disease. Our preliminary work has confirmed that this switch in pathogenic potential is dictated by temperature, with exposure to 37 degrees C suppressing many of the B. cereus phenotypes, leading to a B. anthracis like state. We have shown that this regulatory switch operates at the post-transcriptional level by an as yet unknown mechanism. We argue it is important to understand how readily this mechanism evolved, for estimating the current prevalence and predict future likelihood of other BcG9241-like strains becoming a threat. Indeed, there have been increasing reports of isolates of similar strains from around the world, including the B. cereus biovar anthracis strains. Furthermore, we argue that the current push for industrial scale farming of insects as "food or feed" has the potential risk of creating unintentional "anthrax factories", should a BcG9241-like crossover strain gain access to the resident insect population. It is therefore important to better understand how such strains can achieve this pathogenic switch.