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Sex and virulence in Escherichia coli : an evolutionary perspective
Author(s) -
Wirth Thierry,
Falush Daniel,
Lan Ruiting,
Colles Frances,
Mensa Patience,
Wieler Lothar H.,
Karch Helge,
Reeves Peter R.,
Maiden Martin C. J.,
Ochman Howard,
Achtman Mark
Publication year - 2006
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2006.05172.x
Subject(s) - biology , virulence , pathogenic escherichia coli , genetics , shigella , escherichia coli , microbiology and biotechnology , genome , multilocus sequence typing , gene , pathogen , genotype
Summary Pathogenic Escherichia coli cause over 160 million cases of dysentery and one million deaths per year, whereas non‐pathogenic E. coli constitute part of the normal intestinal flora of healthy mammals and birds. The evolutionary pathways underlying this dichotomy in bacterial lifestyle were investigated by multilocus sequence typing of a global collection of isolates. Specific pathogen types [enterohaemorrhagic E. coli , enteropathogenic E. coli , enteroinvasive E. coli , K1 and Shigella ] have arisen independently and repeatedly in several lineages, whereas other lineages contain only few pathogens. Rates of evolution have accelerated in pathogenic lineages, culminating in highly virulent organisms whose genomic contents are altered frequently by increased rates of homologous recombination; thus, the evolution of virulence is linked to bacterial sex. This long‐term pattern of evolution was observed in genes distributed throughout the genome, and thereby is the likely result of episodic selection for strains that can escape the host immune response.