Quorum sensing-1 signaling of N-hexanoyl-l-homoserine lactone contributes to virulence in avian pathogenic Escherichia coli

Avian pathogenic E. coli (APEC) caused avian colibacillosis is mostly common in poultry industry worldwide. APEC virulence factors lead to pathogenesis and the quorum sensing (QS) system actively involved regulation of these factors. Signaling molecules QS are known as autoinducers (AIs). In QS-1, encodes a single LuxR homolog, i.e., SdiA, but does not express LuxI an acyl-homoserine lactone (AHL) synthase producing AI-1. regulates its genes expression response exogenous AHLs, regulatory mechanisms AHL QS-1 still unknown. This study targeted CE129 isolate reference strain, Yersinia enterocolitica yenI gene was expressed into CE129. CE129/pyenI conferred ability produce signal. The SdiA mutant strain with in-frame sdiA (AHL receptor) deletion constructed by λRed recombination system, which lost sense AHL. goal this explore function upon elucidate effect QS-1/AHL signals strain. Adherence invasion assays revealed that affected adherence survival ability. biofilm formation also suppressed under C6HSL. Interestingly, exhibited different phenotypes acid tolerance flagella when compared enterotoxigenic or enterohemorrhagic (ETEC EHEC, respectively). These findings enhance our understanding mechanism.