Comparison of global transcription responses allows identification of Vibrio cholerae genes differentially expressed following infection

Comparison of global transcription profiles of Vibrio cholerae grown in vit ro and in vivo revealed that 20% of the genome was repressed and about 5% w as induced under in vivo conditions. Hybridization with the cloned genes re vealed that the virulence genes ctx, toxR, toxT and tcpA were induced under in vivo conditions. Dissection of two in vivo induced cosmids identified a nother set of three genes homologous to cheY1 involved in motility and chem otaxis, pnuC encoding the major component of the nicotinamide mononucleotid e transport system and icmF belonging to a cassette involved in multiplicat ion inside host cells. These results demonstrate that the global transcript ion profile approach might be a powerful method for identification of diffe rentially expressed transcripts under in vivo conditions. (C) 2000 Federati on of European Microbiological Societies. Published by Elsevier Science B.V . All rights reserved.