Table 3 Bacterial strains and plasmids used in this study

Strains

 Lactobacillus sakei Lb790

Host strain, meat isolate, non-bacteriocin producer

[22]

 Lactobacillus plantarum NC8

Host strain, silage isolate, plasmid free

[48]

 Lactobacillus casei CECT475

Host strain, cheese isolate, also recorded as strain ATCC393

CECT

 Lactococcus lactis MG1363

Source of SP _usp45 , plasmid-free and prophage-cured derivative of L. lactis NCDO 712

[51]

 Enterococcus faecium T136

Enterocin A and B producer, source of entA and entiA, control strain

DNBTA [52]

 Enterococcus faecium P13

Enterocin P producer, control strain MPA and ADT indicator

DNBTA [52]

 Listeria ivanovii CECT913

Indicator strain, sheep isolate

CECT

 Listeria grayi CECT931

Indicator strain, chinchilla faeces

CECT

 Listeria welshimeri CECT919

Indicator strain, decaying vegetation

CECT

 Listeria seeligeri CECT917

Indicator strain, soil isolate

CECT

 Listeria innocua CECT910

Indicator strain, cow brain isolate

CECT

 Listeria monocytogenes CECT911

Indicator strain, spinal fluid of man

CECT

 Listeria monocytogenes CECT935

Indicator strain, spinal fluid of child

CECT

 Listeria monocytogenes CECT936

Indicator strain, origin not described

CECT

 Listeria monocytogenes CECT939

Indicator strain, chicken isolate

CECT

 Listeria monocytogenes CECT4031

Indicator strain, rabbit isolate

CECT

 Listeria monocytogenes CECT4032

Indicator strain, soft cheese isolate

CECT

Plasmids

 pSIP409

Em^r; pSIP401 with 256_rep and P_orfX::gusA

[28]

 pSIP411

Em^r; pSIP401 with SH71_rep and P_orfX::gusA

[28]

 pMG36c

Cm^r, pMG36e derivative

RUG-MG [30]

 pSIP409UAI

Em^r; pSIP409 derivative encoding the PCR product UAI (SP _usp45 fused to mature entA and entiA genes)

This work

 pSIP411UAI

Em^r; pSIP411 derivative encoding the PCR product UAI (SP _usp45 fused to mature entA and entiA genes)

This work

 pMGUAI

Cm^r, pMG36c derivative encoding the SP _usp45 fused to mature entA and entiA genes)

[13]