Effect of deletion of gene cluster involved in synthesis of Enterobacterial common antigen on virulence and immunogenicity of live attenuated Salmonella vaccine when delivering heterologous Streptococcus pneumoniae antigen PspA

Table 3 Bacterial strains and plasmids

Strain or plasmid	Description of the genotype or relevant characteristics	Source or reference
S. Typhimurium stains
χ3761	Wild type UK-1	[31]
χ9241	ΔpabA1516 ΔpabB232 ΔasdA16 ΔaraBAD23 ΔrelA198::araC P_BADlacI TT	[32]
χ12357	Δ (wecA-wecG)-6, Delete whole ECA operon in χ3761	This study
χ12358	Δ (wecA-wecG)-6, Delete whole ECA operon in χ9241	This study
S. pneumoniae strains	WU2, Wild-type virulent, encapsulated type 3	[34]
Plasmids
pYA4278	SacB mobRP4 R6K ori Cm⁺, pRE112-T-vector	[24]
pYA5493	Delete whole ECA operon	This study
pYA3493	Plasmid Asd⁺; pBRori β-lactamase signal sequence-based periplasmic secretion plasmid	[35]
pYA4088	852-bp DNA encoding the α-helical region of PspA from aa 3–285 in pYA3493	[27]

ISSN: 1471-2180