Table 1 Strains and plasmids used in this study

Strains

   Vibrio harveyi

   BB170

luxN :: Tn5 AI-1 sensor negative; AI-2 sensor positive

[43]

Escherichia coli

   DH5α

endA 1 recA 1 gyrA96 thi-1 hsdR17(r_k^- m_k⁺) relA1 supE44Δ( lacZYA-argF ) U169 F^- Φ80d lacZ Δ M15 deoA phoA λ^-

[21]

   DH5α LuxS

DH5α containing the plasmid pProEx-luxS_EC

[8]

   DH5α Pfs

DH5α containing the plasmid pProEx HT mtan

[8]

Helicobacter pylori

   J99 (ATCC700824)

Wild-type motile strain

[44]

   J99 ΔluxS

J99 derivative; ΔluxS :: km; Km^r

[15]

   J99ΔluxS-F

J99 derivative; ΔluxS :: km-sacB; Km^r Suc^s

This study

   J99 ΔluxS⁺

J99ΔluxS-F derivative; ΔluxS :: km-sacB replaced with original luxS locus; Suc^r Km^s

This study

   J99 ΔmccA

J99 derivative; ΔmccA :: km; Km^r

[15]

   J99 ΔmccB

J99 derivative; ΔmccB :: km; Km^r

[15]

   J99 ΔflhB

J99 derivative; ΔHP0770 Lys¹³ to Glu³⁴⁷; Km^r; non-motile

[24]

   CCUG 17874*

Wild-type strain

[29]

   17874 ΔflaA

17874 derivative; ΔflaA :: cat; Cm^r

Paul O'Toole

   17874 ΔflgE

17874 derivative; ΔflgE :: km; Km^r

[30]

Plasmids

   pGEMT

Commercial TA cloning vector; Amp^r

Promega

   pGEMTluxSXN396

pGEM-T with inserted 26695 luxS; ΔluxS :: km-sacB; Suc^s Km^r

[17]

   pGEMTluxS

pGEM-T with inserted full-length luxS fragment

This study

   pProEx-luxS_EC

pProEX HT containing the luxS gene of E. coli MG1655

[8]

   pProEx HT mtan

PProEX HT containing the pfs gene of E. coli

[8]