Table 1 Strains and plasmids used in this study

Escherichia coli

DH5α

F^-Φ80lacZ∆M15∆(lacZYA-argF)U169 deoR recA1 endA1 hsdR17(r_k^-, m_k⁺) phoA supE44 thi-1 gyrA96 relA1 λ^-

Laboratory collection

EC100D pir-116

F^-mcrA∆(mrr-hsdRMS-mcrBC) Φ 80dlacZ∆M15 ∆lacX74 recA1 endA1 araD139 ∆(ara, leu)7697 galU galK λ- rpsL (Str^R) nupG pir-116(DHFR)

Laboratory collection

EC100D pir-116/R995 + SPI-6

Strain carrying the T6SS_SPI-6 from S. Typhimurium cloned in plasmid R995

This study

EC100D pir-116/R995 + SPI-19

Strain carrying the T6SS_SPI-19 from S. Gallinarum cloned in plasmid R995

[25]

DH5α/R995

Strain harboring an empty R995 vector

This study

DH5α/R995-VC6

Strain harboring plasmid R995-VC6

This study

Salmonella Dublin

CT_02021853

Wild-type strain

Laboratory collection

MSD753

CT_02021853 ∆phoN::FRT

This study

MSD35

CT_02021853 ∆T6SS_SPI-6 ∆T6SS_SPI-19

This study

MSD36

CT_02021853 ∆T6SS_SPI-6

This study

MSD37

CT_02021853 ∆T6SS_SPI-19

This study

WT/R995

CT_02021853 containing an empty R995 vector

This study

MSD35R

MSD35 harboring R995 plasmid

This study

MSD35R6

MSD35 complemented with plasmid R995 + SPI-6

This study

MSD35R19

MSD35 complemented with plasmid R995 + SPI-19

This study

Plasmids

pKD46

bla P_BADbet exo pSC101 oriT^s, Amp^R

[26]

pCLF2

Red-swap redesigned vector, Cam^R

[27]

pCLF4

Red-swap redesigned vector, Kan^R

[27]

pEKA30

IncQ plasmid that constitutively express Cre recombinase, Amp^R

[28]

pVEX1212

Suicide vector harboring a loxP site followed by a Sp^R cassette

[28]

pVEX2212

Suicide vector harboring a loxP site followed by a Cam^R cassette

[28]

R995

Self-transmissible broad-host range IncP vector

[28]

R995-VC6

A derivative of plasmid R995 with a cloned 1,209 bp DNA fragment of T6SS_SPI-6 from S. Dublin

This study

R995 + SPI-6

T6SS_SPI-6 cluster from S. Dublin cloned in vector R995

This study

R995 + SPI-19

T6SS_SPI-19 cluster from S. Gallinarum 287/91 cloned in vector R995

[25]