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Salmonella spp. are environmentally persistent pathogens that have served as one of the important models for understanding how bacteria adapt to stressful conditions. However, it remains poorly understood how they survive extreme conditions encountered outside their hosts. Here we show that the rdar morphotype, a multicellular phenotype characterized by fimbria- and cellulose-mediated colony pattern formation, enhances the resistance of Salmonella to desiccation. When colonies were stored on plastic for several months in the absence of exogenous nutrients, survival of wild-type cells was increased compared to mutants deficient in fimbriae and/or cellulose production. Differences between strains were further highlighted upon exposure to sodium hypochlorite, as cellulose-deficient strains were 1,000-fold more susceptible. Measurements of gene expression using luciferase reporters indicated that …