A quorum sensing-based in vivo expression system and its application in multivalent bacterial vaccine

Table 1 Efficacy of vaccine candidate WED(ironQS-G) against E. tarda EIB202 and A. hydrophila LSA34 in turbot

Immunogen	Vaccination dose	Challenge strain	Challenge dose (CFU/tail)	No. of fish	Mortality ^a (%)	RPS ^b (%)	Effect ^c
Saline	0.1 ml/tail	EIB202	6 × 10³	30 × 3^d	100 ± 0^e	/	/
		LSA34	8 × 10⁷	30 × 3	85 ± 5.8	/	/
WED	10⁷ CFU/tail	EIB202	6 × 10³	30 × 3	23.3 ± 4.7	76.7 ± 4.7	+
		LSA34	8 × 10⁷	30 × 3	73.3 ± 5.8	13.9 ± 6.8	–
WED(ironQS-G)	10⁷ CFU/tail	EIB202	6 × 10³	30 × 3	27.7 ± 5.0	72.3 ± 5.0	+
		LSA34	8 × 10⁷	30 × 3	28.0 ± 7.5	67.0 ± 8.9	+

^aThe mortality was recorded for 4 weeks after challenge, and the observation of surviving fish was extended to 6 weeks.
^bRPS is the relative percent survival, which is defined relative to the saline group. RPS (%) = (1 - mortality of vaccinated fish / mortality of control fish) × 100.
^cIf RPS > 60%, it represents that the vaccine candidate showed protection against challenge, marked as “+”. If RPS < 30%, it represents no protection against challenge strain, marked as “–”.
^d“×3” represents the vaccination and challenge experiments were done in three parallels.
^eThe “±” is standard deviation.

ISSN: 1475-2859