M. Maeda et al., EFFECT OF VARIOUS TREATMENTS ON WHITE SPOT SYNDROME VIRUS (WSSV) FROMPENAEUS-JAPONICUS (JAPAN) AND PENAEUS-MONODON (THAILAND), Gyobyo kenkyu, 33(4), 1998, pp. 381-387
Two causative agents of white spot syndrome (WSS), penaeid rod-shaped
DNA virus (PRDV) from infected kuruma shrimp (Penaeus japonicus) in Ja
pan and systemic ectodermal and mesodermal baculovirus (SEMBV) from bl
ack tiger shrimp (P. monodon) in Thailand, were tested for their sensi
tivities to chemicals, temperature, drying and singlet oxygen (O-1(2))
. The infectivity of the treated PRDV and SEMBV was determined by chal
lenge tests in kuruma shrimp and black tiger shrimp, respectively. Sod
ium hypochlorite inactivated PRDV at 1 ppm for 30 min and at 5 ppm for
10 min. SEMBV was inactivated by sodium hypochlorite at 10 ppm for 30
min. Povidone-iodine inactivated these viruses at a concentration of
10 ppm for 30 min. A high concentration of NaCl (12.5%) inactivated PR
DV in 24 h at 25 degrees C, and 15% NaCl inactivated SEMBV in 24 h at
28 degrees C. PRDV was inactivated by heating at 50 degrees C for 20 m
in, by drying at 30 degrees C, and by using ethyl ether. PRDV in the s
ea water maintained its infectivity for at least 120 days at 4 degrees
C, and for more than 60 days but less than 120 days when kept at 25 d
egrees C. However, PRDV, when suspended in sea water at a lower concen
tration, maintained infectivity for 10 days at 4 degrees C and for 7 d
ays at 25 degrees C. SEMBV maintained infectivity in sea water for 5 d
ays at 28 degrees C PRDV was exposed to O-1(2), which was generated by
an insoluble dye (rose bengal) and visible light. Shrimp that receive
d O-1(2)-exposed virus showed lower mortality than control shrimp, ind
icating that O-1(2) inactivated PRDV. This O-1(2) generating system is
a simple, safe and effective technique that can be applied to aquacul
ture.