The assessment of leading traits in the taxonomy of the Bacillus cereus group

Abstract

Bacillus cereus sensu lato strains (B. cereus group) are widely distributed in nature and have received interest for decades due to their importance in insect pest management, food production and their positive and negative repercussions in human health. Consideration of practical uses such as virulence, physiology, morphology, or ill-defined features have been applied to describe and classify species of the group. However, current comparative studies have exposed inconsistencies between evolutionary relatedness and biological significance among genomospecies of the B. cereus group. Here, the combined analyses of core-based phylogeny and all versus all Average Nucleotide Identity values based on 2116 strains were conducted to update the genomospecies circumscriptions within B. cereus group. These analyses suggested the existence of 57 genomospecies, 37 of which are novel, thus indicating that the taxonomic identities of more than 39% of the analyzed strains should be revised or updated. In addition, we found that whole-genome in silico analyses were suitable to differentiate genomospecies such as B. anthracis, B. cereus and B. thuringiensis.

Phylogenetic and protein prediction analysis reveals the taxonomically diverse distribution of virulence factors in Bacillus cereus strains

“…The formula was balanced using the mean value method and was subjected to calculation using DrawGram in the PHYLIP package version 3.695 [ 25 ]. To determine the associations between each protein-coding gene and the different clusters, statistical enrichment analyses were conducted with PhyloGLM V2.6 [ 17 ].…”

“…B . cereus , as a genomospecies, could be mainly found in clade two based MLSA and multiple comparative analysis of ANI values [ 17 ]. Later, seven major phylogenetic groups with ecological differences were identified in the B .…”

Three novel species of the Bacillus cereus group isolated from clinical samples in Japan

“…Torres Manno et al suggested the existence of 24 novel genomospecies of the B. cereus group based on ANI values of 2116 strains [23]. ANI values were determined among the three novel type strains, BML-BC004 T , BML-BC017 T and BML-BC059 T and representative strains of the 24 novel genomospecies (Table S5).…”

Dissecting the Environmental Consequences of Bacillus thuringiensis Application for Natural Ecosystems

“…Bt belongs to Bacillus cereus sensu lato (or the Bc group), a taxonomic unit of volatile species content [ 7 , 8 ]. Initially, the Bc group comprised three relatively distinct species, namely, B. anthracis , B. cereus, and B. thuringiensis , which were characterized based on clinically and agriculturally important phenotypic traits [ 9 ].…”

“…By now, different authors distinguish 6 [ 9 ], 8 [ 10 ], or 11 [ 11 ] species. The advances of genome-wise phylogeny have allowed for the identification of 20 [ 11 ] and even 37 putative genomospecies [ 7 ]. Alternatively, prior to the aforementioned phylogenetic studies, the Bc group had been suggested to be perceived as a single species with immensely diversified and adaptable phenotypes [ 1 , 12 ].…”