JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow An erratum has been published
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Rachek, L. I.
Right arrow Articles by Wood, D. O.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Rachek, L. I.
Right arrow Articles by Wood, D. O.

J Bacteriol, April 1998, p. 2118-2124, Vol. 180, No. 8
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

Transformation of Rickettsia prowazekii to Rifampin Resistance

Lyudmila I. Rachek, Aimee M. Tucker, Herbert H. Winkler, and David O. Wood*

Department of Microbiology and Immunology, Laboratory of Molecular Biology, University of South Alabama College of Medicine, Mobile, Alabama 36688

Received 4 December 1997/Accepted 16 February 1998

Rickettsia prowazekii, the causative agent of epidemic typhus, is an obligate intracellular parasitic bacterium that grows directly within the cytoplasm of the eucaryotic host cell. The absence of techniques for genetic manipulation hampers the study of this organism's unique biology and pathogenic mechanisms. To establish the feasibility of genetic manipulation in this organism, we identified a specific mutation in the rickettsial rpoB gene that confers resistance to rifampin and used it to demonstrate allelic exchange in R. prowazekii. Comparison of the rpoB sequences from the rifampin-sensitive (Rifs) Madrid E strain and a rifampin-resistant (Rifr) mutant identified a single point mutation that results in an arginine-to-lysine change at position 546 of the R. prowazekii RNA polymerase beta  subunit. A plasmid containing this mutation and two additional silent mutations created in codons flanking the Lys-546 codon was introduced into the Rifs Madrid E strain of R. prowazekii by electroporation, and in the presence of rifampin, resistant rickettsiae were selected. Transformation, via homologous recombination, was demonstrated by DNA sequencing of PCR products containing the three mutations in the Rifr region of rickettsial rpoB. This is the first successful demonstration of genetic transformation of Rickettsia prowazekii and represents the initial step in the establishment of a genetic system in this obligate intracellular pathogen.

* Corresponding author. Mailing address: Department of Microbiology and Immunology, Laboratory of Molecular Biology, University of South Alabama College of Medicine, Mobile, AL 36688. Phone: (334) 460-6324. Fax: (334) 460-7269. E-mail: wood{at}sungcg.usouthal.edu.




This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 1998 by the American Society for Microbiology. All rights reserved.