Chlamydia trachomatis lacks an adaptive response to changes in carbon source availability.

Most bacteria coordinately regulate gene expression as an adaptive response to a variety of environmental changes. One key environmental cue is the carbon source necessary for central metabolism. We used microarray analysis to monitor the global transcriptional response of the obligate intracellular pathogen Chlamydia trachomatis to the presence of glycolytic and gluconeogenic carbon sources. In contrast to free-living bacteria, changing the carbon source from glucose to glutamate or alpha-ketoglutarate had little effect on the global gene transcription of C. trachomatis.