Transcriptome analysis of Escherichia coli O157:H7 EDL933 inside Acanthamoeba using microarrays

The transcriptome of Escherichia coli K-12 has been widely studied over a variety of conditions for the past decade while such studies involving E. coli O157:H7, its pathogenic cousin, are just now being conducted. To better understand the impact of intracellular life within a ruminant and environmental protozoan on E. coli O157:H7, global transcript levels of strain EDL933 cells inside Acanthamoeba were compared to cell grown in the protozoan media (ATCC PYG712) by microarray. Nine independent RNA samples from cell from within Acanthamoeba were paired with seven independent RNA samples from control cultures for hybridization to nine two-color microarrays. For four arrays, the control RNA sample was labeled with Cy3 dye and the experimental RNA sample was labeled with Cy5 dye, the dyes were reversed for the other five arrays to overcome dye bias.