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

Lead Research Organisation: University of Warwick
Department Name: School of Life Sciences

Abstract

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.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
BB/M01116X/1 01/10/2015 30/09/2023
1786911 Studentship BB/M01116X/1 03/10/2016 31/01/2021 Grace Taylor-Joyce
 
Description The impact of the horizontally acquired pBCXO1 virulence plasmid on the transcriptome of B. cereus G9241 was assed and this worked showed that the virulence plasmid is influencing chromosomal genes with a wide variety of biological functions including membrane proteins, cell metabolism and amino acid biosynthesis as well as many others. This analysis also showed that the influence the plasmid has on the chromosome is much stronger at 37°C, the mammalian host temperature, then it is at 25°C. This large data set has opened up new research questions about how the change in gene expression caused by the presence of the pBCXO1 virulence plasmid is affecting how this pathogen interacts with its host and causes disease.
Exploitation Route The large data set of transcriptomic results could be used by other researchers looking at the effect of pBCXO1 or pXO1 virulence plasmids in either B. cereus or B. anthracis.
Sectors Aerospace, Defence and Marine,Agriculture, Food and Drink,Healthcare,Pharmaceuticals and Medical Biotechnology