Table 1.

Summary of bacterial strains and plasmids used in this study.

Bacterial strain or plasmid	Notable characteristic (s)a	Source of reference
BACTERIAL STRAINS
E. coli DH5α	Plasmid cloning host	Purchased from Invitrogen
ZY05719	Virulent strain of SS2 isolated from a dead pig	Lab collection
ZY05719 MhsdS	ZY05719 transposon mutants obtained by TnYLB-1 insertion within the open reading frame (ORF) of gene hsdS	Lab collection Liu et al., 2016
ZY05719 ΔhsdS′	Isogenic hsdS′ mutant of strain ZY05719	This study
ZY05719 ΔlysM	Isogenic lysM mutant of strain ZY05719	This study
ZY05719 ΔlysM′	Isogenic lysM′ mutant of strain ZY05719	This study
ZY05719 CMhsdS	Complemented strain of ZY05719 MhsdS, Spcr	This study
ZY05719 CΔhsdS′	Complemented strain of ZY05719 ΔhsdS′, Spcr	This study
PLASMIDS
pSET4s	S. suis thermosensitive suicide vector, Spcr	Takamatsu et al., 2001a
pSET2	E. coli- Streptococcus shuttle cloning vector, Spcr	Takamatsu et al., 2001b
pSET4s::hsdS′ UDb	Recombinant vector designed to knock out gene hsdS′, Spcr	This study
pSET4s::lysM UDb	Recombinant vector designed to knock out gene lysM, Spcr	This study
pSET4s::lysM′ UDb	Recombinant vector designed to knock out gene lysM′, Spcr	This study
pSET2::hsdS	pSET2 containing hsdS in the EcoR I-BamH I restriction sites, Spcr	This study
pSET2::hsdS′	pSET2 containing hsdS′ in the EcoR I-BamH I restriction sites, Spcr	This study

^aSpc^r, spectinomycin.

^bUD, upstream and downstream flanking sequences of a gene.