Abstract
Recombinant bacteria secreting the transmembrane-truncated region ofwhite spot syndrome virus (WSSV)
envelope protein VP28 named DhpVB were constructed, using live Escherichia coli as a deliverer and a constitutive
secretory expression plasmid as the expression vector. With the ability to deliver recombinant protein
products outside, DhpVB couldmake VP28 directly interact with the shrimp when injected into shrimp.
In order to test the protection potential, live DhpVB were injected into the marine shrimp Exopalamon
carincauda Holthuis for three times and WSSV challenge was performed twice simultaneously at the last
two injections of the bacteria. The results showed that DhpVB displayed statistically significant advantage
over bacteria without VP28 after the second challenge with an average RI (Resistance index) of 0.67±0.08,
compared with 0.41±0.09 of bacteria without VP28 (P