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Pathogens in decay


Three bacterial genomes that have recently been published identify common evolutionary strategies among extremely disparate organisms. All of these species inhabit specialized niches in association with eukaryotic organisms, and all of them show evidence of the long-term genome decay that accompanies the acquisition of the restricted lifestyle of a pathogen or endosymbiont.

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Figure 1: These photographs of a flea (a) and two ticks (b) were taken during a 1972 study of disease carriers and pests found in and around migrant labour camps.
Figure 2


  1. 1

    McLeod, M. P. et al. Complete genome sequence of Rickettsia typhi and comparison with sequences of other rickettsiae. J. Bacteriol. 186, 5842–5855 (2004).

    CAS  Article  Google Scholar 

  2. 2

    Andersson, S. G. et al. The genome sequence of Rickettsia prowazekii and the origin of mitochondria. Nature 396, 133–140 (1998).

    CAS  Article  Google Scholar 

  3. 3

    Ogata, H. et al. Mechanisms of evolution in Rickettsia conorii and R. prowazekii. Science 293, 2093–2098 (2001).

    CAS  Article  Google Scholar 

  4. 4

    Horn, M. et al. Illuminating the evolutionary history of chlamydiae. Science 304, 728–730 (2004).

    CAS  Article  Google Scholar 

  5. 5

    Hartl, D. L. The origin of malaria: mixed messages from genetic diversity. Nature Rev. Microbiol. 1, 15–22 (2004).

    Article  Google Scholar 

  6. 6

    Monteiro-Vitorello, C. B. et al. The genome sequence of the Gram-positive sugar cane pathogen Leifsonia xyli subsp. xyli. Mol. Plant Microbe Interact. 17, 827–836 (2004).

    CAS  Article  Google Scholar 

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Chlamydia pneumoniae

Escherichia coli

Leifsonia xyli subsp. xyli CTCB07

Rickettsia conorii

Rickettsia prowazekii

Rickettsia typhi

Parachlamydia sp. UWE25

Xylella fastidiosa


The Pathogen Sequencing Unit

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Cerdeño-Tárraga, A., Thomson, N. & Parkhill, J. Pathogens in decay. Nat Rev Microbiol 2, 774–775 (2004).

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