IAI FigSearch
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 Gahan, C. G. M.
Right arrow Articles by Hill, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gahan, C. G. M.
Right arrow Articles by Hill, C.

 Previous Article  |  Next Article 

Infection and Immunity, June 2001, p. 3924-3932, Vol. 69, No. 6
0019-9567/01/$04.00+0   DOI: 10.1128/IAI.69.6.3924-3932.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.

Characterization of the groESL Operon in Listeria monocytogenes: Utilization of Two Reporter Systems (gfp and hly) for Evaluating In Vivo Expression

Cormac G. M. Gahan,* James O'Mahony, and Colin Hill

Department of Microbiology and National Food Biotechnology Centre, University College Cork, Cork, Ireland

Received 8 January 2001/Returned for modification 13 February 2001/Accepted 26 March 2001

The ability of intracellular pathogens to sense and adapt to the hostile environment of the host is an important factor governing virulence. We have sequenced the operon encoding the major heat shock proteins GroES and GroEL in the gram-positive food-borne pathogen Listeria monocytogenes. The operon has a conserved orientation in the order groES groEL. Upstream of groES and in the opposite orientation is a gene encoding a homologue of the Bacillus subtilis protein YdiL, while downstream of groEL is a gene encoding a putative bile hydrolase. We used both reverse transcriptase-PCR (RT-PCR) and transcriptional fusions to the UV-optimized Aequorea victoria green fluorescent protein (GFPUV) to analyze expression of groESL under various environmental stress conditions, including heat shock, ethanol stress, and acid shock, and during infection of J774 mouse macrophage cells. Strains harboring GFPUV transcriptional fusions to the promoter region of groESL demonstrated a significant increase in fluorescence following heat shock that was detected by both fluorimetry and fluorescence microscopy. Using both RT-PCR and GFP technology we detected expression of groESL following internalization by J774 cells. Increased intracellular expression of dnaK was also determined using RT-PCR. We have recently described a system which utilizes L. monocytogenes hemolysin as an in vivo reporter of gene expression within the host cell phagosome (C. G. M. Gahan and C. Hill, Mol. Microbiol. 36:498-507, 2000). In this study a strain was constructed in which hemolysin expression was placed under the control of the groESL promoter. In this strain hemolysin expression during infection also confirms transcription from the groESL promoter during J774 and murine infection, albeit at lower levels than the known virulence factor plcA.

* Corresponding author. Mailing address: Department of Microbiology, University College Cork, Cork, Ireland. Phone: 353-21-4902080. Fax: 353-21-4903101. E-mail: c.gahan{at}ucc.ie.

Infection and Immunity, June 2001, p. 3924-3932, Vol. 69, No. 6
0019-9567/01/$04.00+0   DOI: 10.1128/IAI.69.6.3924-3932.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2001 by the American Society for Microbiology. All rights reserved.