TY - JOUR T1 - Pathogenicity of Vibrio penaeicida or white shrimp Litopenaeus vannamei: a cysteine protease-like exotoxin as a virulence factor A1 - Aguirre Guzman,G A1 - Ascencio,F A1 - Saulnier,Denis AD - Ctr Invest Biol Noroeste, Unidad Patol Marina, La Paz, Baja California, Mexico. AD - IFREMER, French Res Inst Exploitat Sea, Lab Genet & Pathol, F-17390 La Tremblade, France. UR - https://archimer.ifremer.fr/doc/00000/3618/ DO - 10.3354/dao067201 KW - Pathogenicity KW - Exotoxin KW - Shrimp KW - Litopenaeus vannamei KW - Cysteine protease KW - Vibrio penaeicida N2 - The pathogenicity of Vibrio penaeicida Strains KH-1 and AM101, their culture-free supernatant (CFS), and their protein fraction obtained by 40% of ammonium sulfate precipitation (PFs40) were assessed in experimental challenges against juvenile Litopenaeus vannamei. Live Vibrio cells, CFS, and PFs40 from the AM101 strain produced a significantly higher mortality (p < 0.05) compared to the KH-1 strain. Toxicity and median lethal doses (LD50) of Fast Protein Liquid Chromatography (FPLC) products were evaluated on L. vannamei. The first FPLC fraction sample (A) from PFs40 of the AM101 strain displayed LD50 values of 1.68 and 5.61 mu g protein ind.(-1), respectively. The second FPLC process from Fraction A showed a peak (A1) also with toxic effects to shrimp. PFs40, Fraction A, and Peak At showed a 38.5 kDa molecular band (SDS-PAGE), with activity on a gelatin protease zymogram. The lethal effect of PFs40 and Fraction A was inhibited by Proteinase K, CuCl2, E-64, and heat (60 and 100 degrees C) treatments, but was not inhibited by EDTA-Na-2, aprotinin, and soy trypsin treatments. These results and the zymogram inhibition test suggest the presence of a cysteine protease-like proteinaceous exotoxin as a dominant protease, secreted by V. penaeicida Strain AM101. Y1 - 2005/11 PB - Inter-Research JF - Diseases of aquatic organisms SN - 0177-5103 VL - 67 IS - 3 SP - 201 EP - 207 ID - 3618 ER -