Biochemical and Biophysical Research Communications, Vol.513, No.3, 651-656, 2019
Disruption of SpoIIID decreases sporulation, increases extracellular proteolytic activity and virulence in Bacillus anthracis
Endospores are important for maintenance of the B. anthracis lifecycle and necessary for its effective spread between hosts. Our experiments with B. anthracis showed that disruption of SpollID results in a spore formation defect, as determined by heat resistance assays and microscopic assessment. We further found complete engulfment by the Delta spollID mutant strain by membrane morphology staining but no synthesis of the clarity coat and exosporium by transmission electron microscopy. Reduced transcription and expression of small acid-soluble spore protein(sasP-2) and the spore development associated genes (sigma(K), gerE and cotE) in the mother cell were found in the Delta spoIIID strain, suggesting that the spore formation defect in B. anthracis AI6R is related to decreased transcription and expression of these genes. Extracellular protease and virulence enhancement in the Delta spollID strain may be related to the elevation of metalloproteinases (TasA and Camelysin) levels. Our findings pave the way for further research on the regulation network of sporulation, survival and virulence in these two morphological forms of B. anthracis. (C) 2019 Elsevier Inc. All rights reserved.