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 Bahl, M. I.
Right arrow Articles by Sørensen, S. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bahl, M. I.
Right arrow Articles by Sørensen, S. J.

 Previous Article  |  Next Article 

Antimicrobial Agents and Chemotherapy, April 2004, p. 1112-1117, Vol. 48, No. 4
0066-4804/04/$08.00+0     DOI: 10.1128/AAC.48.4.1112-1117.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

In Vivo Detection and Quantification of Tetracycline by Use of a Whole-Cell Biosensor in the Rat Intestine

Martin Iain Bahl,1,2 Lars Hestbjerg Hansen,1 Tine Rask Licht,2 and Søren J. Sørensen1*

Department of Microbiology, University of Copenhagen, 1307 Copenhagen K,1 Institute of Food Safety and Nutrition, Danish Veterinary and Food Administration, 2860 Søborg, Denmark2

Received 19 August 2003/ Returned for modification 26 September 2003/ Accepted 21 December 2003

An Escherichia coli biosensor strain, harboring the plasmid pTGFP2, was introduced into the gastrointestinal tract of gnotobiotic rats that continuously received drinking water containing tetracycline. Plasmid pTGFP2 contains a transcriptional fusion between a green fluorescent protein (GFP) gene and a tetracycline-regulated promoter and was shown to produce a proportional GFP signal in response to exposure to various tetracycline concentrations when harbored by an E. coli strain. The plasmid was highly unstable in the host bacteria colonizing the intestinal system of the animals, and rapid plasmid loss was observed. Reintroduction of the E. coli MC4100/pTGFP2 strain into animals already colonized by the plasmid-free E. coli strain the day before euthanasia made it possible to extract and analyze the biosensors from intestinal samples. The induction of GFP in the biosensor cells extracted from the animals was estimated on a single-cell basis by use of flow cytometry, and the mean induction of GFP in the samples was compared to a standard curve prepared from known tetracycline concentrations. The results showed that the bioavailable tetracycline concentration within the bacterial growth habitat of the intestine was proportional to the concentration of tetracycline in drinking water but represented only approximately 0.4% of the intake concentration. This is a significant finding which will help to clarify antimicrobial therapy in the intestinal environment.

* Corresponding author. Mailing address: Department of Microbiology, University of Copenhagen, Sølvgade 83H, 1307 Copenhagen K, Denmark. Phone: 45 35 32 20 53. Fax: 45 35 32 20 40. E-mail: sjs{at}mermaid.molbio.ku.dk.

Antimicrobial Agents and Chemotherapy, April 2004, p. 1112-1117, Vol. 48, No. 4
0066-4804/04/$08.00+0     DOI: 10.1128/AAC.48.4.1112-1117.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Norman, A., Hestbjerg Hansen, L., Sorensen, S. J. (2005). Construction of a ColD cda Promoter-Based SOS-Green Fluorescent Protein Whole-Cell Biosensor with Higher Sensitivity toward Genotoxic Compounds than Constructs Based on recA, umuDC, or sulA Promoters. Appl. Environ. Microbiol. 71: 2338-2346 [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»