A Shift to Human Body Temperature (37°C) Rapidly Reprograms Multiple Adaptive Responses in Escherichia coli That Would Facilitate Niche Survival and Colonization.

One of the first environmental cues sensed by a microbe as it enters a human host is an upshift in temperature to 37°C. In this dynamic time point analysis, we demonstrate that this environmental transition rapidly signals a multitude of gene expression changes in Escherichia coli. Bacteria grown at 23°C under aerobic conditions were shifted to 37°C, and mRNA expression was measured at time points after the shift to 37°C ( = 0.

Genome-wide identification of H-NS-controlled, temperature-regulated genes in Escherichia coli K-12.

DNA microarrays demonstrate that H-NS controls 69% of the temperature regulated genes in Escherichia coli K-12. H-NS is shown to be a common regulator of multiple iron and other nutrient acquisition systems preferentially expressed at 37 degrees C and of general stress response, biofilm formation, and cold shock genes highly expressed at 23 degrees C.

Low temperature (23 degrees C) increases expression of biofilm-, cold-shock- and RpoS-dependent genes in Escherichia coli K-12.

Temperature serves as a cue to regulate gene expression in Escherichia coli and other bacteria. Using DNA microarrays, we identified 297 genes whose expression is increased at 23 degrees C compared to 37 degrees C in E. coli K-12.

Human body temperature (37degrees C) increases the expression of iron, carbohydrate, and amino acid utilization genes in Escherichia coli K-12.

Using DNA microarrays, we identified 126 genes in Escherichia coli K-12 whose expression is increased at human body temperature (37 degrees C) compared to growth at 23 degrees C. Genes involved in the uptake and utilization of amino acids, carbohydrates, and iron dominated the list, supporting a model in which temperature serves as a host cue to increase expression of bacterial genes needed for growth. Using quantitative real-time PCR, we investigated the thermoregulatory response for representative genes in each of these three categories (hisJ, cysP, srlE, garP, fes, and cirA), along with the fimbrial gene papB.

The N-acetyltransferase RimJ responds to environmental stimuli to repress pap fimbrial transcription in Escherichia coli.

In uropathogenic Escherichia coli, P pili (Pap) facilitate binding to host epithelial cells and subsequent colonization. Whereas P pili can be produced at 37 degrees C, the expression of these fimbriae is suppressed at 23 degrees C. Previously, insertion mutations in rimJ, a gene encoding the N-terminal acetyltransferase of ribosomal protein S5, were shown to disrupt this thermoregulatory response, allowing papBA transcription at low temperature.