The various biological roles of sRNA elements encompass
the regulation of metabolism, growth processes or adaptation
to stress. Moreover, recent evidence shows that
regulatory RNAs play key roles in microbial pathogenesis
(Gong et al., 2011; Koo et al., 2011; Toledo-Arana et al.,
2007; Vogel, 2009; Waters & Storz, 2009). During infection,
bacterial pathogens have to adapt rapidly to changing
environmental conditions in the host, including survival
strategies in specific niches, avoidance of exposure to the
immune system and systemic toxicity. Among the multiple
infectious strategies that bacterial pathogens have developed,
regulatory RNAs are considered as signal transducers
of environmental cues by participating in the precise
coordination of gene expression. Several sRNAs have been
shown to regulate the synthesis of virulence factors and
other pathogenic traits by adapting the bacterial metabolism
in response to the host.