@article{PAR00006835,
  title = {{G}enomes of the most dangerous epidemic bacteria have a virulence repertoire characterized by fewer genes but more toxin-antitoxin modules},
  author = {{G}eorgiades, {K}. and {R}aoult, {D}idier},
  abstract = {{B}ackground: {W}e conducted a comparative genomic study based on a neutral approach to identify genome specificities associated with the virulence capacity of pathogenic bacteria. {W}e also determined whether virulence is dictated by rules, or if it is the result of individual evolutionary histories. {W}e systematically compared the genomes of the 12 most dangerous pandemic bacteria for humans ("bad bugs") to their closest non-epidemic related species ("controls"). {M}ethodology/{P}rincipal {F}indings: {W}e found several significantly different features in the "bad bugs", one of which was a smaller genome that likely resulted from a degraded recombination and repair system. {T}he 10 {C}luster of {O}rthologous {G}roup ({COG}) functional categories revealed a significantly smaller number of genes in the "bad bugs", which lacked mostly transcription, signal transduction mechanisms, cell motility, energy production and conversion, and metabolic and regulatory functions. {A} few genes were identified as virulence factors, including secretion system proteins. {F}ive "bad bugs" showed a greater number of poly ({A}) tails compared to the controls, whereas an elevated number of poly ({A}) tails was found to be strongly correlated to a low {GC}% content. {T}he "bad bugs" had fewer tandem repeat sequences compared to controls. {M}oreover, the results obtained from a principal component analysis ({PCA}) showed that the "bad bugs" had surprisingly more toxin-antitoxin modules than did the controls. {C}onclusions/{S}ignificance: {W}e conclude that pathogenic capacity is not the result of "virulence factors" but is the outcome of a virulent gene repertoire resulting from reduced genome repertoires. {T}oxin-antitoxin systems could participate in the virulence repertoire, but they may have developed independently of selfish evolution.},
  keywords = {},
  journal = {{P}los {O}ne},
  volume = {6},
  numero = {3},
  pages = {p. e17962},
  ISSN = {1932-6203},
  year = {2011},
  DOI = {10.1371/journal.pone.0017962},
  URL = {http://www.documentation.ird.fr/hor/{PAR}00006835},
}