This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
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 Groh, J. L.
Right arrow Articles by Krumholz, L. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Groh, J. L.
Right arrow Articles by Krumholz, L. R.
Agricola
Right arrow Articles by Groh, J. L.
Right arrow Articles by Krumholz, L. R.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, January 2007, p. 492-498, Vol. 73, No. 2
0099-2240/07/$08.00+0     doi:10.1128/AEM.01086-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Genes That Enhance the Ecological Fitness of Shewanella oneidensis MR-1 in Sediments Reveal the Value of Antibiotic Resistance{triangledown} ,{dagger}

Jennifer L. Groh,1 Qingwei Luo,1 Jimmy D. Ballard,2 and Lee R. Krumholz1*

Department of Botany and Microbiology, University of Oklahoma, Norman, Oklahoma 73019,1 Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 731902

Received 11 May 2006/ Accepted 7 November 2006

Environmental bacteria persist in various habitats, yet little is known about the genes that contribute to growth and survival in their respective ecological niches. Signature-tagged mutagenesis (STM) of Shewanella oneidensis MR-1 coupled with a screen involving incubations of mutant strains in anoxic aquifer sediments allowed us to identify 47 genes that enhance fitness in sediments. Gene functions inferred from annotations provide us with insight into physiological and ecological processes that environmental bacteria use while growing in sediment ecosystems. Identification of the mexF gene and other potential membrane efflux components by STM demonstrated that homologues of multidrug resistance genes present in pathogens are required for sediment fitness of nonpathogenic bacteria. Further studies with a mexF deletion mutant demonstrated that the multidrug resistance pump encoded by mexF is required for resistance to antibiotics, including chloramphenicol and tetracycline. Chloramphenicol-adapted cultures exhibited mutations in the gene encoding a TetR family regulatory protein, indicating a role for this protein in regulating expression of the mexEF operon. The relative importance of mexF for sediment fitness suggests that antibiotic efflux may be a required process for bacteria living in sediment systems.

* Corresponding author. Mailing address: Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73019. Phone: (405) 325-0437. Fax: (405) 325-7619. E-mail: krumholz{at}ou.edu.

{triangledown} Published ahead of print on 17 November 2006.

{dagger} Supplemental material for this article may be found at http://aem.asm.org/.

Applied and Environmental Microbiology, January 2007, p. 492-498, Vol. 73, No. 2
0099-2240/07/$08.00+0     doi:10.1128/AEM.01086-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Toes, A.-C. M., Daleke, M. H., Kuenen, J. G., Muyzer, G. (2008). Expression of copA and cusA in Shewanella during copper stress. Microbiology 154: 2709-2718 [Abstract] [Full Text]  
  • Luo, Q., Groh, J. L., Ballard, J. D., Krumholz, L. R. (2007). Identification of Genes That Confer Sediment Fitness to Desulfovibrio desulfuricans G20. Appl. Environ. Microbiol. 73: 6305-6312 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»