Abstract
BackgroundBacillus cereus sensu lato s.l.) is a group of bacteria displaying close phylogenetic relationships but a high ecological diversity. The three most studied species are Bacillus anthracis, Bacillus cereus sensu stricto and Bacillus thuringiensis. While some species are pathogenic to mammals or associated with food poisoning, Bacillus thuringiensis is a well-known entomopathogenic bacterium used as biopesticide worldwide. B. cereus s.l. also contains a large variety of mobile genetic elements (MGEs).ResultsIn this study, we detail the occurrence and plasmid vs. chromosome distribution of several MGEs in 102 complete and annotated genomes of B. cereus s.l. These MGEs include 16 Insertion Sequence (IS) families, the Tn3 family, 18 different Bacillus cereus repeats (BCRs) and 30 known group II introns.ConclusionsOur analysis not only shows the diversity of these MGEs among strains of the same species and between different species within the B. cereus s.l. group, but also highlights the potential impact of these elements on the plasticity of the plasmid pool, and the TEs (Transposable Elements) - species relationship within B. cereus s.l.
Highlights
Bacillus cereus sensu lato s.l.) is a group of bacteria displaying close phylogenetic relationships but a high ecological diversity
B. cereus sensu lato genomes One hundred and two complete genome sequences belonging to B. cereus s.l. were retrieved from the NCBI (National Center for Biotechnology Information) genome database (Table 1)
Of the forty-two complete genomes assigned in the NCBI database as B. thuringiensis, eight strains did not contain any delta-endotoxins and were marked as “cry- ”(crystal-)
Summary
B. cereus sensu lato genomes One hundred and two complete genome sequences belonging to B. cereus s.l. were retrieved from the NCBI (National Center for Biotechnology Information) genome database (Table 1). The second observation is about the distribution of ISs and Tn3-like elements among the different species of the B. cereus group Families such as IS3, IS4 and IS200/ IS605 are ubiquitous among B. cereus s.l. while others, such as IS1, IS30 and IS982, are rarely present The presence of several copies of the same element (Additional file 1: Table S4) suggests that it was once mobile Another important observation is that most of group II introns located in B. cereus s.l. genomes belong to the RNA type IIB. HD1011, c25 and YGD22–03 were not considered, since they carry only a fragment of the cry or cyt (delta-endotoxin and cytolysin, respectively) chromosomal genes Even though they represent only 30.6% of the total B. thuringiensis plasmid repertoire, toxin-carrying plasmids hold 36.9, 49.4 and 44.4% of the total plasmidial ISs, Tn3-like elements, bcr repeats and group II introns, respectively. ISs and Tn3-like elements represent in size 7.46% of the toxin-carrying plasmids vs. 5.33% for the other plasmids
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
