Table 1. Bacterial strains used in this study.

Strains	luxS	Description	Source or reference
C. jejuni 81-176	+	Wild type, virulent clinical isolate from a gastroenteritis outbreak	ATCC
C. jejuni NCTC 11168	+	Wild type, isolated from clinical sample in the UK in 1977	NCTC
C. jejuni 81-176ΔluxS	−	luxS- deletion mutant, Cmr	He et al. [14]
C. jejuni 81-176ΔluxS +pBQ117	+	luxS- deletion mutant complemented with pBQ117, Cmr, Kmr,	This study
C. jejuni 81-176luxS +pBQ1015	−	luxS- deletion mutant with Campylobacter vector pBQ1015, Cmr, Kmr	This study
C. jejuni 81-176::luxS	−	luxS- insertion mutant, Cmr	Quinones et al. [15]
C. jejuni 81-176::luxS +pBQ117	+	luxS- insertion mutant complemented with pBQ117, Cmr, Kmr,	Quinones et al. [15]
C. jejuni 81-176::luxS +pBQ1015	−	luxS- insertion mutant with Campylobacter vector pBQ1015, Cmr, Kmr	Quinones et al. [15]
C. jejuni NCTC 11168ΔluxS	−	luxS- deletion mutant, Kmr	Corcionivoschi et al. [34]
V. harveyi BB152		AI-2 positive control in luminescence Bioassay	Bassler et al. [16]
V. harveyi BB170		AI-2 reporter in luminescence Bioassay	Bassler et al. [16]

Cm, chloramphenicol; Km, kanamycin.