A mutation inactivating the methyltransferase gene in avirulent Madrid E strain of Rickettsia prowazekii reverted to wild type in the virulent revertant strain Evir

Jian Zhi Zhang, Jun Fang Hao, David H. Walker, Xue Jie Yu

Research output: Contribution to journalArticle

24 Scopus citations


Rickettsia prowazekii Madrid E (E) strain is an effective vaccine, but can revert to virulent status when passaged in animals. The aim of this study is to identify the reverse mutation that may determine the virulence of R. prowazekii by comparing the genetic structures of E strain and its virulent revertant Evir strain. We determined that the gene (Rp028/Rp027) encoding the methyltransferase was mutated by frameshift in avirulent E strain but not in virulent revertant Evir strain and wild type virulent Breinl strain. We conclude that the mutation in the E strain gene reverts to wild type in the virulent revertant Evir strain. Whether the mutation plays an essential role in the attenuation of E strain needs to be further investigated.

Original languageEnglish (US)
Pages (from-to)2317-2323
Number of pages7
Issue number13
StatePublished - Mar 20 2006



  • Epidemic typhus
  • Methyltransferase
  • Reverse virulence mutation
  • Rickettsia prowazekii

ASJC Scopus subject areas

  • Molecular Medicine
  • Immunology and Microbiology(all)
  • veterinary(all)
  • Public Health, Environmental and Occupational Health
  • Infectious Diseases

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