Vibriosis is the disease that most influences shrimp culture. Bacterial Gram-negative caused vibriosis from the family Vibrionaceae, including V. harveyi, V. alginolyticus, V. parahaemolyticus, V. vulnificus, V. cholera, and V. splendidus (de Souza Valente and Wan, 2021). Acute hepatopancreatic necrosis disease (AHPND) was first reported as increasing the expression of lipid doplets protein Periliperin caused by a strain of Vibrio parahaemolyticus (Vp(AHPND)) infection (Wang et al., 2022). Vibrio parahaemolyticus Vp5 was a local isolate from Pacific white shrimp culture in Indonesia (unpublished).
All shrimp indicated high mortality in infection 106 CFU/mL as acute infection. In contrast, the challenge with V. parahaemolyticus Vp5 at a density 103 CFU/mL did not lead to any mortality. Subsequently, the L.vannamei challenged at 107 CFU/mL of AHPND positive Vibrio resulted more than 50% mortality within 48 h post-challenge (Muthukrishnan et al., 2019). Based on histopathology, severe necrosis with loss of tissue, ruptured cells, and sloughing were detected in the hepatopancreas. The hepatopancreas as a vital organ of crustacean including shrimp is involved in diverse metabolic activities, excretion, molting, and storage of energy (Verri et al., 2001). The tubule epithelial cells extensive necrosis and damaged epithelial cells were detected in the midgut. This results was positive correlation with other report that the PirABVP toxin produce focal damage in midgut and hindgut region, especially on epithelial cells of Pacific white shrimp (Kumar et al., 2019). These lesions in hepatopancreas are similar to those caused by AHPND that reported by (Lee et al., 2015). AHPND is given, including the disease-associated gross signs and histopathology changes (Kumar et al., 2021a).
Metabolomic intestine of juvenile Pacific white shrimp after different challenges concentration from 103 to 106 CFU/mL shows that no significant different metabolites with Control (significant different P < 0.05). Infection using V. parahaemolyticus Vp5 concentrations 104, 105, dan 106 CFU/mL made changing of intestine metabolites of Pacific white shrimp. Metabolite diethyl phytalate was conserved compound in Control and treatment. The dynamic of relative abundance of the Top 10 metabolites shows that pentacosane was decreased from Control to a high concentration of V. parahaemolyticus Vp5. In contrast, Spermidine was significantly increased in shrimps by EHP infection (Ning et al., 2019). Six amino acid (threonine, asparagine, 4-aminobutyric acid, histidine, ornithine, glutamine) were decreases in haemolymph challenged shrimp using V. parahaemolyticus caused AHPND (Nguyen et al., 2021). Pentacosane is a saturated hydrocarbon known as alkane and belongs to the class of organic compounds. Metabolite pentacosane can be a potential metabolite marker for acute infection of V. parahaemolyticus. The healthy shrimp have a significant high concentration of pentacosane compared infected shrimp (P < 0.05). Based on PCA and PLS-DA analysis, pentacosane was lost abundance in acute infection of V. parahemolyticus Vp5. The absense of pentacosane may have correlation with the decrease of immune system caused of V. parahaemolyticus Vp5 infection. Pentacosane may serve as important fragrant for healthy shrimp. Eight unique metabolites in average (Control) shrimp without infection of V. parahaemolyticus Vp5 were Heptadecane, 2; Octane 5 ethyl; 2,4-Ditert-bu; Triacontane 1; Phythalic acid; Nordextrometho; 9-Tricosene; and Pentadecane. On the other hand, seven metabolites unique to acute infection of V. parahaemolyticus Vp5 were 2-Isoprophyl-5; Heptadecane; Cyclononasilox; Hexadecane,2-; 9-(2’,2’-Dimet); Tetracosamethy; Squalene; and Decane,2,3,6- (Fig. 8). Metabolite correlation have 3 clusters based on clustering PCA, the first cluster was Control and dosage 103 CFU/mL that grouping in same cluster because they have high similarity, the second cluster was 104 CFU/mL and the last cluster was dosage 105 and 106 CFU/mL (Fig. 9). The important of shrimp health status after differs infection of V. parahaemolyticus Vp5 in relation to the intestine metabolome profile was identified to be species-specific. However, other factors might explain the metabolome changes in Pacific white shrimp. Key pathways altered during AHPND infection were fatty acid biosynthesis, steroid hormone biosynthesis, and primary bile acid biosynthesis (Kumar et al., 2021b). Vibrio challenge led to increases of five TCA cycle intermediates including citric acid, fumaric acid, isocitric acid, succinic acid, cis-aconitic acid, and phospophenolpyruvic acid (PEP) (Nguyen et al., 2021).
In this study, the molecular response induced by V. parahaemolyticus Vp5 were investigated at metabolite levels in intestine of L. vannamei. The metabolic biomarkers in hepatopancreas after EHP infection could induce an immune response, disturbances in hormone mechanism, and energy metabolism in shrimp after (Ning et al., 2019). We suggested that metabolite pentacosane is most suitable for metabolite marker of infection V. parahaemolyticus Vp5. Further research shows that pentacosane can be used as primary data for development of diagnostic tests based on fragrant for checking shrimp health status and quality. One strategy is to investigate the metabolite markers of various infections and diseases that come not only in Pacific white shrimp but also in common shrimp through a significant correlation between infection and metabolome data.