Salmonella response to copper and zinc

Salmonella can infect a wide range of hosts and survive in the environment. This invasive pathogen has therefore evolved and acquired specific traits to cope with different, and in most cases unfavorable, conditions. In particular, transition metal ions are widely spread in these niches. These ions are essential in biology and play key roles in the structure-function of a large number of proteins. They can also be toxic, especially at high concentrations. Intracellular metal ion concentrations must therefore be tightly controlled to maintain normal metabolism. Salmonella has acquired traits to deal with the presence of toxic concentrations of some of these ions and, at the same time, to fulfill its requirement for essential metal ions when they are scarce. In this work we analyze the transcriptional response of Salmonella enterica to copper and zinc, two of these essential metals, in both rich (SLB) and defined (M9) media and at short times (10 minutes). This tiling-array based work provides a detailed description of the main transcriptional response when Salmonella detects fluctuations in copper and zinc concentrations. 14028s cells were grown up to OD 0.6, then, copper 10 uM (M9) or 1 mM (SLB) or Zn 50uM (M9) or 0.25 mM (SLB) was added and bacteria were grown for 10 minutes, RNA was isolated after this time. The RNA from bacteria grown without metal was also isolated. Each sample was analized by duplicate.