Bacteria—and especially those capable of persisting in diverse environments, such as Escherichia coli—provide particularly valuable models for exploring how single-celled organisms respond to environmental stresses. For example, most bacteria associated with foodborne infections (e.g., some E. coli serotypes, Salmonella enterica serovar Typhimurium, Listeria monocytogenes) can survive under diverse conditions, both inside and outside of the host.