AAC
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
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 Burtnick, M. N.
Right arrow Articles by Woods, D. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Burtnick, M. N.
Right arrow Articles by Woods, D. E.

 Previous Article  |  Next Article 

Antimicrobial Agents and Chemotherapy, November 1999, p. 2648-2656, Vol. 43, No. 11
0066-4804/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.

Isolation of Polymyxin B-Susceptible Mutants of Burkholderia pseudomallei and Molecular Characterization of Genetic Loci Involved in Polymyxin B Resistance

Mary N. Burtnick and Donald E. Woods*

Department of Microbiology and Infectious Diseases, University of Calgary Health Sciences Center, Calgary, Alberta, Canada T2N 4N1

Received 24 April 1999/Returned for modification 2 June 1999/Accepted 26 August 1999

Burkholderia pseudomallei is a gram-negative bacterium that causes the disease known as melioidosis. This pathogen is endemic to Southeast Asia and northern Australia and is particularly problematic in northeastern Thailand. It has been previously reported that B. pseudomallei is resistant to the killing action of cationic antimicrobial peptides, including human neutrophil peptide, protamine sulfate, poly-L-lysine, magainins, and polymyxins. Recently, we have also found that the virulent clinical isolate B. pseudomallei 1026b is capable of replicating in media containing polymyxin B at concentrations of >100 mg/ml. In order to identify genetic loci that are associated with this particular resistance phenotype, we employed a Tn5-OT182 mutagenesis system in coordination with a replica plating screen to isolate polymyxin B-susceptible mutants. Of the 17,000 Tn5-OT182 mutants screened via this approach, five polymyxin B-susceptible mutants were obtained. Three of these mutants harbored Tn5-OT182 insertions within a genetic locus demonstrating strong homology to the lytB gene present in other gram-negative bacteria. Of the remaining two mutants, one contained a transposon insertion in a locus involved in lipopolysaccharide core biosynthesis (waaF), while the other contained an insertion in an open reading frame homologous to UDP-glucose dehydrogenase genes. Isogenic mutants were also constructed via allelic exchange and used in complementation analysis studies to further characterize the relative importance of each of the various genetic loci with respect to the polymyxin B resistance phenotype exhibited by B. pseudomallei 1026b.

* Corresponding author. Mailing address: Department of Microbiology and Infectious Diseases, University of Calgary Health Sciences Center, 3330 Hospital Dr. N.W., Calgary, Alberta, Canada T2N 4N1. Phone: (403) 220-2564. Fax: (403) 283-5241. E-mail: woods{at}ucalgary.ca.

Antimicrobial Agents and Chemotherapy, November 1999, p. 2648-2656, Vol. 43, No. 11
0066-4804/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Clin. Vaccine Immunol. Clin. Microbiol. Rev.
J. Clin. Microbiol. ALL ASM JOURNALS

Copyright © 1999 by the American Society for Microbiology. All rights reserved.