Genomic analysis of three African strains of Bacillus anthracis demonstrates that they are part of the clonal expansion of an exclusively pathogenic bacterium. Issue 6 (28th September 2014)

• Record Type: Journal Article
• Authors: Rouli, L.; MBengue, M.; Robert, C.; Ndiaye, M.; La Scola, B.; Raoult, D.
• Is Part Of: New microbes and new infections. Volume 2:Issue 6(2014)
• Page Start: 161
• Page End: 169
• Publication Date: 2014-09-28
• Subjects: Medical microbiology -- Periodicals; Communicable diseases -- Periodicals; Infection -- Periodicals; Microbiology -- Periodicals; Communicable Diseases -- Periodicals; Infection -- Periodicals; 616.9041
• DOI: 10.1002/nmi2.62
• Languages: English
• ISSNs: 2052-2975

Abstract

<abstract abstract-type="main" id="nmi262-abs-0001"> <title>Abstract</title> <p> <italic>Bacillus anthracis</italic> is the causative agent of anthrax and is classified as a 'Category A' biological weapon. Six complete genomes of <italic>B. anthracis</italic> (A0248, Ames, Ames Ancestor, CDC684, H0491, and Sterne) are currently available. In this report, we add three African strain genomes: Sen2Col2, Sen3 and Gmb1. To study the pan‐genome of <italic>B. anthracis</italic>, we used bioinformatics tools, such as Cluster of Orthologous Groups, and performed phylogenetic analysis. We found that the three African strains contained the pX01 and pX02 plasmids, the nonsense mutation in the <italic>plcR</italic> gene and the four known prophages. These strains are most similar to the CDC684 strain and belong to the A cluster. We estimated that the <italic>B. anthracis</italic> pan‐genome has 2893 core genes (99% of the genome size) and 85 accessory genes. We validated the hypothesis that <italic>B. anthracis</italic> has a closed pan‐genome and found that the three African strains carry the two plasmids associated with bacterial virulence. The pan‐genome nature of <italic>B. anthracis</italic> confirms its lack of exchange (similar to <italic>Clostridium tetani</italic>) and supports its exclusively pathogenic role, despite its survival in the environment. Moreover, thanks to the study of the core content single nucleotide polymorphisms, we can see that our three African strains diverged very recently from the other <italic>B. anthracis</italic> strains.</p> </abstract>