In-vivo Test of Chlorella Protein Fragments as Nucleotide Vaccine Candidates in Grouper Viral Nervous Necrosis (VNN) Infection against Haematological Response

Abstract

Grouper (Cromileptes altivelis) is a species of fish with important economic values both in the national and international markets. The disease that has been reported by researchers is Viral Nervous Necrosis (VNN) which can cause mass death in groupers, especially in larval and juvenile stadia. Based on the problems, a research is needed on haematological analysis of groupers (Cromileptes altivelis) infected with Viral Nervous Necrosis by in-vivo testing using protein fragments of C. vulgaris. This research employed an experiment method using 5 treatments, namely (A) healthy fish, (B) VNN-infected fish, (C) VNN-infected fish with administration of C.vulgaris crude extracts of 17 μg mL-1, (D) VNN-infected fish with administration of C.vulgaris crude extract of 33 μg mL-1, and (E) VNN-infected fish with administration of C.vulgaris crude extract of 50 μg mL-1. Observations of haematological parameters included erythrocytes, leukocytes, haemoglobin, and haematocrit. The observation results showed an erythrocyte value of 97 x 104 cells/mm3 in treatment (C), 107 x 104 cells/mm3 in treatment (D), and 94 x 104 cells/mm3 in treatment (E). The observation results of leukocyte values were 150,000 cells/mm3 in treatment (C), 133,300 cells/mm3 in treatment (D), and 139,000 cells/mm3 in treatment (E). Furthermore, the observation results of haemoglobin showed a value of 5 gr/100 ml in treatment (C), 6 gr/100 ml in treatment (D), and 5 gr/100 ml in treatment (E). As for the haematocrit parameter, the results obtained from the observation were 18% in treatment (C), 22% in treatment (D), and 15% in treatment (E). Based on this research, the haematological status of VNNinfected groupers was not good. However, the results of the in-vivo testing conducted showed that administration of C. vulgaris extract gave a positive result on improving the haematological status of groupers (C. altivelis) infected with VNN with the optimal dose of 33 μg mL-1.