Lethal Attribute of Serine Protease Secreted by Vibrio alginolyticus Strains in Kuruma Prawn Penaeus japonicus

Abstract

Toxicity of the extracellular products (ECP) and the lethal attribute of serine protease secreted by five pathogenic Vibrio alginolyticus strains from various sources in kuruma prawn Penaeus japonicus were studied. The ECPs of organisms originally isolated from diseased kuruma prawn or small abalone Haliotis diversicolor supertexta were more lethal (LD50 value of 0.48 or 0.41 μg protein/g prawn) than those from diseased tiger prawn P.monodon, yellowfin porgy Acanthopagrus latus or horse mackerel (LD50 value of 0.98 -1.17 μg protein/g prawn). All the ECPs manifested strong, weak and no activities against gelatin, sheep erythrocytes and chitin, respectively. In immunodiffusion tests using rabbit antiserum to a purified 33 kDa serine protease of strain Swy against ECP of each tested strain produced one single precipitation band in each treatment. Furtherm ore, the serine protease was suggested to be the dominant protease secreted by V. alginolyticus strains tested since the majority of enzymatic activity of the respective ECP was inhibited by phenylmethanesulfonyl fluoride (PMSF). A higher inhibition of serine protease activity by PMSF resulted in lower mortality rate of the ECPs injected into the prawns suggesting that the protease is one of the major lethal factor(s) secreted by Valginolyticus.

The Extracellular Metalloprotease ofVibrio tubiashiiIs a Major Virulence Factor for Pacific Oyster (Crassostrea gigas) Larvae

“…For instance, for Vibrio harveyi, a cysteine protease acts as a major exotoxin in the tiger prawn (26), while for Vibrio alginolyticus, a serine protease is reported to be the dominant protease secreted as well as a major pathogenicity factor in the tiger prawn (5). In this study, however, only metalloprotease inhibitors severely impaired the toxicity of culture supernatants to Pacific oyster larvae.…”

Vibrio parahaemolyticus and V. harveyi cause detachment of the epithelium from the midgut trunk of the penaeid shrimp Sicyonia ingentis

“…V. proteolyticus releases a toxin that causes disassembly of zonula adherens between adjacent gut cells in the brine shrimp Artemia, the subsequent degeneration of these cells, and the penetration of the bacterium deeper into the body (Verschuere et al 2000). Work on related species of Vibrio include identification of toxins in V. cholerae that cause cell rounding by affecting the cytoskeleton (Fullner & Mekalanos 2000), a zonula occludens toxin (Wu 1997), a lethal serine protease secreted by V. alginolyticus (Chen et al 2000), and factors that affect hemostasis (Lee et al 1999). Under natural conditions, shrimp are exposed to multiple microbes, and bacteriophages may affect the toxicity of V. harveyi (Ruangpan et al 1999), and Bacillus subtilis may work as a probiotic treatment against pathogenic Vibrio (Rengpipat et al 2003, Vaseeharan & Ramasamy 2003.…”

“…Vibriosis is a bacterial disease responsible for mortality of cultured shrimp worldwide (Lightner & Lewis 1975, Adams 1991, Lavilla-Pitogo et al 1998, Chen et al 2000. Outbreaks may occur when environmental factors trigger the rapid multiplication of bacteria already tolerated at low levels within shrimp blood (Sizemore & Davis 1985), or by bacterial penetration of host barriers.…”

Anti-Bacterial Activity of Natural Plants on Fish Pathogens Isolated from Different Ponds of Dhaka City

“…Poor water quality and the commencement of disease in aquaculture claim one of the major environmental problems those could affect the overall sanitary as well health condition 9,[31][32] . This study was indeed designed a model with subsequent simulations to find out some strategies to combat these problems.…”