“…In most cases, AI-2 has been implicated in controlling bacterial virulence. For example, LuxS is known to regulate the expression of a number of virulence genes involved in the pathogenesis of bacteria like enterohemorrhagic E. coli (EHEC) (Sperandio et al, 1999), enteropathogenic E. coli (EPEC) (Sircili et al, 2004;Sperandio et al, 1999), Neisseria meningitidis (Winzer et al, 2002), Vibrio cholerae (Zhu et al, 2002), Bacillus anthracis (Jones et al, 2010) or affecting biological behaviors such as B. anthracis bacterial growth (Jones et al, 2010), Klebsiella pneumoniae and Streptococcus pneumoniae biofilm formation (Balestrino et al, 2005;Vidal et al, 2011) and V. cholerae motility (Zhu et al, 2002). Although many studies have been carried out in the above-mentioned bacteria, the association between the luxS gene and the virulence of APEC has not been determined.…”