Send to

Choose Destination
Proc Natl Acad Sci U S A. 2007 Nov 13;104(46):18229-34. Epub 2007 Nov 6.

An in vivo expression technology screen for Vibrio cholerae genes expressed in human volunteers.

Author information

Center for Vaccine Development and Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.


In vivo expression technology (IVET) has been widely used to study gene expression of human bacterial pathogens in animal models, but has heretofore not been used in humans to our knowledge. As part of ongoing efforts to understand Vibrio cholerae pathogenesis and develop improved V. cholerae vaccines, we have performed an IVET screen in humans for genes that are preferentially expressed by V. cholerae during infection. A library of 8,734 nontoxigenic V. cholerae strains carrying transcriptional fusions of genomic DNA to a resolvase gene was ingested by five healthy adult volunteers. Transcription of the fusion leads to resolvase-dependent excision of a sacB-containing cassette and thus the selectable phenotype of sucrose resistance (Suc(R)). A total of approximately 20,000 Suc(R) isolates, those carrying putative in vivo-induced fusions, were recovered from volunteer stool samples. Analysis of the fusion junctions from >7,000 Suc(R) isolates from multiple samples from multiple volunteers identified 217 candidate genes for preferential expression during human infection. Of genes or operons induced in three or more volunteers, the majority of those tested (65%) were induced in an infant mouse model. VC0201 (fhuC), which encodes the ATPase of a ferrichrome ABC transporter, is one of the identified in vivo-induced genes and is required for virulence in the mouse model.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center