Construction of attenuated Salmonella typhimurium Strain expressing Helicobacter pylori conservative region of adhesin antigen and its immunogenicity

Table 1 Strain (plasmid) and genotype

Strain (plasmid)	Genotype	Source
E coli X6097	Asd-	Dr. Roy Curtiss
Salmonella
typhimurium X3181	Wild strain	Institute for the control of biological product, Ministry of Health
X3730	GalE-, hsd-, asd-	Dr. Roy Curtiss
X4072	Cya-, Crp-, Asd-	Dr. Roy Curtiss
pET-22b (+) -AB	Ampr, AB	Construction in the previous research[17-20], Dr. Roy Curtiss
pYA248	Asd+	Construction in the research
pYA248-AB	AB

Table 2 Expression of AB in X4072 (PYA248-AB) assayed by bridged ELISA

Sample	A492nm	P/N
Negtive control of X4072 (pYA248) culture supernatant	0.04
Negtive control of X4072 (pYA248) sonicate supernatant	0.04
Positive control of BL21 (pET-AB) periplasm	1.08	27.0
X4072 (pYA248-AB) culture supernatant	0.96	24.0
X4072 (pYA248-AB) sonicate supernatant	0.78	19.5

Table 3 Survival of mice after oral inoculation with virulent and recombinant S.typhimurium strains

Strain	Relevant phenotype	Inoculating dose (c.f.u)	Observation intervals (d)	Survial (live/total)
X3181	wild type	1.0 × 107	5	0/5
		2.6 × 105	30	2/5
X4072 (PYA248-AB)	Cya-Crp-AB+	1.0 × 1010	30	5/5